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Lithos 102 (200

Geochronology and geochemistry of the Mesozoic volcanicrocks in Western Liaoning: Implications for lithospheric

thinning of the North China Craton

Wei Yang, Shuguang Li ⁎

CAS Key laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences,University of Science and Technology of China, Hefei, Anhui 230026, China

Received 17 October 2006; accepted 24 September 2007Available online 11 October 2007

Abstract

Determining the age and petrogenesis of the voluminous Mesozoic magmatic rocks from the North China Craton (NCC) providescritical data for deducing the process and timing of lithospheric thinning. Four Mesozoic magmatic events in the northeast of the craton(Western Liaoning) are delineated by Ar–Ar and U–Pb zircon dating, i.e. the Xinglonggou Formation (177 Ma), the Lanqi Formation(166–153 Ma), the Yixian Formation (126–120Ma), and the Zhanglaogongtun Formation (∼106Ma), respectively. The Xinglonggoulavas are high-Mg# adakites with arc-like Sr–Nd–Pb isotopic compositions, suggesting that they originated from the subductedPalaeoasian oceanic crust. The typical “continental” geochemical signatures of the Lanqi basalts and basaltic andesites as well as theirlow ɛNd(t), moderate 87Sr/86Sri, and extremely unradiogenic Pb isotopes indicate significant involvement of lower crust materials in theirmagma. These features, coupled with the low Mg, Ni, and Cr contents may suggest significant olivine fractionation and a magmaunderplating event, which caused the partial melting of the low-middle crust to produce the voluminous low-Mg andesites and acidicvolcanic rocks overlying the Lanqi basalts. The Yixian high-Mg adakitic rocks with the lower-crustal Sr–Nd–Pb isotopic compositionssuggest foundering of the mafic lower crust into the underlying convecting mantle. The Yixian basalts show similar geochemicalcharacteristics to the Lanqi basalts except the relatively higher Mg, Ni and Cr contents, which could be derived from a newly enrichedlithosphere mantle hybridized by partial melts from the foundered lower continental crust. The Zhanglaogongtun lavas are alkalinebasalts with MORB-like Sr–Nd–Pb isotopic compositions, suggesting derivation from a depleted mantle. Based on the new data, amulti-stage lithospheric thinning model is proposed.© 2007 Elsevier B.V. All rights reserved.

Keywords: North China Craton; Western Liaoning; Lithospheric thinning; Geochronology and geochemistry of volcanic rocks; Magmaunderplating; Foundering of mafic lower crust

1. Introduction

The lithospheric mantle of the North China Craton(NCC) has attracted considerable attention over the last

⁎ Corresponding author.E-mail address: lsg@ustc.edu.cn (S. Li).

0024-4937/$ - see front matter © 2007 Elsevier B.V. All rights reserved.doi:10.1016/j.lithos.2007.09.018

two decades (e.g., Menzies et al., 1993; Deng et al., 1994,1996; Griffin et al., 1998; Guo et al., 2001; Gao et al.,2002; Zhang et al., 2002, 2003; Chen et al., 2003; Wuet al., 2003; Deng et al., 2004; Xu et al., 2004a,b; Rudnicket al., 2004; Zhang et al., 2004; Zhang, 2005). Studies ondiamond-bearing kimberlites and mantle xenoliths indi-cate a thick (∼200 km) and cold (∼40 mW/m2)

89W. Yang, S. Li / Lithos 102 (2008) 88–117

lithosphere existing in the NCC during the Paleozoic (Fanand Menzies, 1992; Griffin et al., 1992, 1998; Zhenget al., 2003). However, investigations of Cenozoic basalt-borne spinel lherzolite xenoliths show that the Cenozoiclithosphere is relatively thinner (b80 km) and hotter(∼60mW/m2) beneath the eastern NCC (Fan et al., 2000;Zheng et al., 2001). This was also demonstrated bygeophysical data (Ma, 1987). Therefore, it is suggestedthat about 120 km of lithosphere has been removed sincethe early Paleozoic. In addition, the Paleozoic lithosphericmantle also differs from the Cenozoic one in geochemicalcharacteristics. The former is characterized by EMIIisotopic compositions, such as high 206Pb/204Pb (∼20.2),significant variation of 87Sr/86Sr, and negative ɛNd (−5)(Zheng and Lu, 1999; Zhang et al., 2002), while theCenozoic lithospheric mantle shows Sr–Nd–Pb isotopiccompositions similar to the mid-ocean ridge basalt(MORB) and ocean island basalt (OIB) (Peng et al.,1986; Song et al., 1990; Basu et al., 1991).Apparently, thegeochemical features of the lithospheric mantle in easternChina have been significantly changed during theevolution from the Paleozoic to the Cenozoic.

The reason for the removal and replacement of thePaleozoic lithospheric mantle has not been well under-stood yet. Possible mechanisms include destabilization ofthe NCC due to the Indo-Eurasian collision (Menzieset al., 1993), mechanical–chemical erosion and replace-ment by asthenosphere upwelling (Menzies and Xu,1998; Xu, 2001; Xu et al., 2004a,b), delamination andfoundering of thickened lower continental crust (Gaoet al., 2004;Wu et al., 2005), destruction of the lithospheredue to the subduction of oceanic crust in the Paleozoic andcontinental crust in the Mesozoic beneath both thenorthern and southern margins of the NCC (Zhanget al., 2003), and hydro-weakening of the sub-continentallithospheric mantle (SCLM) due to migratory or slab-derived fluids (Niu, 2005).

In addition, the mantle sources of theMesozoic basaltsfrom the NCC are highly heterogeneous, with negativeɛNd (up to −20), variable 87Sr/86Sri, unradiogenic Pbisotope ratios, and typical “continental” geochemicalsignatures such as enrichment of large ion lithophileelements (LILE, e.g., Rb and Ba) and depletion of highfield strength element (HFSE, e.g., Nb and Ta) (Qiouet al., 1997; Fan et al., 2001; Guo et al., 2001; Qiou et al.,2002; Zhang and Sun, 2002; Zhang et al., 2002, 2003;Guo et al., 2003; Chen andZhai, 2003; Li andYang, 2003;Liu et al., 2004a; Xu et al., 2004a,b; Yang et al., 2004;Zhang et al., 2004, 2005b; Zhang, 2005). These featuresare not consistent with a source in either the Paleozoic orCenozoic lithospheric mantle (Peng et al., 1986; Songet al., 1990; Basu et al., 1991; Zhang et al., 2002). The

petrogenesis of the Mesozoic mantle-derived rocks is stillcontroversial. It has been generally suggested that such“continental” geochemical signatures were derived froman enriched SCLM or hybridized upwelling astheno-sphere and three models have been proposed. The firstmodel considers that the SCLM has an EMI-typecomposition resulting from subduction-related multiplemetasomatism processes in the Archaean and Mesopro-terozoic during the accretion of the NCC (e.g., Yang et al.,2004; Ma and Xu, 2006). The second model suggests thatthe Mesozoic SCLM has been modified by a Si–Alenriched melt from partial melting of deeply subductedcrustal materials from the South China block (SCB)(Zhang et al., 2002, 2003). The third model proposes thatthe Mesozoic SCLM was formed by hybridization of theupwelling asthenospheric mantle and SiO2-rich meltsfrom partial melting of the foundered mafic lowercontinental crust (Gao et al., 2004; Lustrino, 2005;Huang et al., 2007a,b).

Mesozoic volcanic rocks with variable ages are widelydeveloped in Western Liaoning, the north margin of theNCC (Chen et al., 1997, 1999). Four major periods ofvolcanism have been identified by stratigraphic studies(Chen et al., 1997; Wang et al., 1989): the early Jurassic(Xinglonggou Formation), the mid-Jurassic (Lanqi For-mation in Western Liaoning or Tiaojishan Formation inNorthernHebei), the early Cretaceous (Yixian Formation),and the late early Cretaceous (Zhanglaogongtun Forma-tion) (Table 1). Geochronological and geochemical studiesof these Jurassic–Cretaceous rocks provide an excellentopportunity to probe the evolution of the underlyinglithospheric mantle and to give constraints on the NCClithospheric thinning process. Previous studies havemainly focused on the origin of the Mesozoic volcanicrocks inWestern Liaoning (e.g., Chen et al., 1997; Li et al.,2001; Shao et al., 2001; Li et al., 2002; Zhang et al., 2003;Gao et al., 2004; Wang et al., 2005; Zhang and Zhang,2005; Zhang et al., 2005a; Li, 2006). However, more dataare still required, because (1) only the timing of the YixianFormation (126–120Ma) has been well dated by both U–Pb and Ar–Ar methods (Swisher et al., 1999, 2001; Wanget al., 2001a,b; Zhou et al., 2003; Ji et al., 2004; Yang et al.,2007) due to the discovery of the famous Jehol biota in theformation (Hou et al., 1995; Hou, 1996; Chen et al., 1998;Ji et al., 1998), (2) previous geochemical studies mainlyfocused on the high-Sr, low-Yandesites, but neglected thebasalts (e.g., Chen et al., 1997; Li et al., 2001, 2002; Gaoet al., 2004;Wang et al., 2005; Zhang and Zhang, 2005;Zhang et al., 2005a; Li, 2006), and (3) the publishedgeochemical data have not beenwell related to the regionaltectonic evolution, which is critical in discussion of themechanism of the lithospheric thinning.

Table 1A summary table showing the strata units in Western Liaoning, volcanic rock types, ages, geochemical characteristics, tectonic settings andinterpretations

Strata Isotopic agerange (Ma)

Rock types Geochemicalcharacteristics

Tectonics Interpretations

The SunjiawanFormation

The ZhanglaogongtunFormation

ca. 106 Basalt Alkaline basaltswith MORB-likeSr–Nd–Pb isotopic ratios.

Asthenosphericupwelling caused bythe large scale E–Wextension.

The Fuxin Formation The strike-slipTan-Lu fault wastransformed intoan extensional graben.

The JiufotangFormation

The YixianFormation

126–120 Basalt,basaltic andesite,andesite and rhyolite.

Basalts and basaltic andesitesshow the typical continentgeochemical signatures andrelative higher Mg, Ni and Crcontents. Andesites are high-Mg#adakites with the low crustalSr–Nd–Pb isotopic compositions.

Large sale strike-slipof the Tan-Lu fault,which caused thelithosphere destructionand pull apart basin.

Foundering of themafic lowercontinental crust

The TuchengziFormation

Pre-135 Ma thrusttectonics is marked bycoarseclastic depositsof the Tuchengziformation.

The Lanqi(Tiaojishan) Formation

166–148 Basalt, basalticandesite, andesiteand rhyolite.

Basalts and basaltic andesitesshow the typical continentgeochemical signatures but lowMg, Ni and Cr contents. Low Mgandesites with crustal Sr–Nd–Pbisotopic compositions

A magmaunderplating eventwith the AFCprocess.

The HaifanggouFormation

Pre-160 Ma thrusttectonics is marked byunconformity beneaththe Lanqi formation

The Beipiao FormationThe XinglonggouFormation

ca. 177 andesite and dacites High-Mg# adakites witharc-like Sr–Nd–Pbisotopic compositions

Partial melting ofthe subductedoceanic crust

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In the present study we have selected a suite ofvolcanic rocks from the region for a detailed geochro-nological and geochemical investigation. Our primaryobjectives include (1) to date each Mesozoic magmaticevent in the region precisely, (2) to characterize thesource composition of basalts with variable ages, and (3)to constrain the source and melt generation processes ofthe high-Sr, low-Y andesites with variable ages. Thenew geochronological and geochemical data provideinsights into the lithospheric evolution of the northmargin of the NCC. Using the present data, togetherwith previously published geochemical and geologicalresults from this area, we propose a multi-stage model toexplain the lithospheric thinning process of the NCC.

2. Geological background and petrography

The North China Craton is one of the oldestcontinental nuclei in the world (Jahn et al., 1987; Liuet al., 1992) and the largest cratonic block in China. It isbounded on the south by the Paleozoic to TriassicQinling–Dabie–Sulu orogenic belt (Li et al., 1993;Meng and Zhang, 2000) and on the north by the CentralAsian Orogenic Belt (Sengör et al., 1999; Davis et al.,2001). The craton is cut by the Tan-Lu Fault Zone,which is a strike-slip fault from the Jurassic to earlyCretaceous (Zhu et al., 2001a, 2005) and was transferredinto an extensional graben in the later Cretaceous andTertiary (Zhu et al., 2001b) (Fig. 1a).

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The Qinling–Dabie–Sulu belt resulted from thecontinental collision between the NCC and the YangtzeCraton in the Triassic (Li et al., 1993). The northwardsubduction of the Yangtze slab was proposed to haveaffected the upper mantle beneath the Dabie orogen andthe south margin of the NCC and influenced theMesozoic basaltic magmatism in the south margin ofthe NCC, such as the post-collisional mafic–ultramaficintrusions (Li et al., 1998; Huang et al., 2007a) and theFangcheng basalts (Zhang et al., 2002).

The Central Asian Orogen was formed to the north ofthe NCC by a southward subduction and an arc–arccollision followed by arc–continent collision during thePaleozoic (Robinson et al., 1999; Davis et al., 2001;Buchan et al., 2002). After collision of the NCC with the

Fig. 1. (a) Simplified geological map of the North China Craton and its surrCenozoic basalts and Archaean terrains in the NCC is after Liu et al. (1994) aLiaoning (modified after Zhang et al., 2003). XL-ML Fault, CF-KY Fault andand Jinxi–Yaolugou Fault, respectively.

southern Central Asian Orogen at the Solonker suture atthe end of the Permian (Xiao et al., 2003), the NCC andthe attached southern Central Asian Orogen collidedwith the northern Central Asian Orogen in the Jurassic(Tomurtogoo et al., 2005). The Solonker suture and theXilamulun River Fault form the northern boundary of theNCC. The Yanshan belt may be due to this southwardsubduction and the subsequent collision (Davis et al.,2001).

Western Liaoning lies in the east of the Yanshan beltand to the west of the Tan-Lu fault, which is bounded bythe Jinxi–Yaolugou fault on the south and the Chifeng–Kaiyuan fault on the north (Fig. 1b). VoluminousJurassic–Cretaceous volcanic rocks were erupted intoa series of small Mesozoic basins in the area.

ounding areas (modified after Huang et al., 2004). The distribution ofnd Jahn (1990). (b) Distribution of Mesozoic volcanic rocks in WesternJX-YL Fault represent Xilamulun River Fault, Chifeng–Kaiyuan Fault,

92 W. Yang, S. Li / Lithos 102 (2008) 88–117

The Xinglonggou lavas occur along a narrow belt inWestern Liaoning (Fig. 2a), which consist of high-Mgandesites, and dacites, inter-layered with tuffs andsandstones. A rhyolitic dike cutting across the volca-no-sedimentary strata has been observed in the Xin-glonggou village. Sample XLG-1 is an andesite from theXinglonggou village, Beipiao City. It is massive, darkgray and contains orthopyroxene phenocrysts. SampleXLG-4 is a light purple tuff with pyroclasts (sodicplagioclase+quartz).

The Lanqi lavas, distributed widely in the Beipiao–Yixian area (Fig. 2a), mainly consist of basalts, andesitesand rhyolites. HFG-13 and HFG-15 are basalts collected

Fig. 2. Geologic map of Beipiao (a), Fuxin. (b) (after LNGMR, 1989) and Dathe Xinglonggou Formation to the west of Beipiao, the type section of the LYixian Formation to the south of Beipiao (a), the Wuhuanchi and Jianguo sectthe Daohugou section (c), respectively.

from the lower bed of the Lanqi Formation inHaifanggou of Beipiao (N 41°50.484′, E 120°46.009′).The samples are massive and dark gray and containplagioclase and clinopyroxene phenocrysts. Sample LQ-6, LQ-9, LQ-10, LQ-11, HFG-27, and HFG-29 werecollected from the Haifanggou–Dalanqi section crossingthe Lanqi formation in Beipiao, and samples LQ-15 toLQ-29 were from the Lanqi formation near the Shuiquanvillage, Beipiao city (Fig. 2a). They consist of basalticandesite (LQ-6), andesites (LQ-15 to LQ-22), andesiteporphyrite (HFG-29), and rhyolites (HFG-27, LQ-9,LQ-10, LQ-11, LQ-27, LQ-28, and LQ-29). Theandesites are massive and gray. The rhyolites are red–

ohugou (c) (after Ren et al., 2002). Our samples are from the outcrop ofanqi Formation to the north of Beipiao, the Sihetun type section of theion of the Zhanglaogongtun Formation to the northeast of Fuxin (b) and

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brown with flow lines. A tuff sample (DHG-1) and anandesite sample (DHG-2) were collected from theDaohugou section located in the Daohugou area,Ningcheng County, Inner Mongolia (Fig. 2c). The stratain the Daohugou section are correlated with the lowerpart of the Tiaojishan/Lanqi Formation by means ofextensively regional geological survey (Ren et al., 2002;Liu et al., 2004b) and biostratigraphic studies (Shen etal., 2003).

The Yixian Formation contains the most voluminousigneous rocks with a thickness of 1000–2000 m (Fig. 2a),beginning with basalts and ending with rhyolites (Ji et al.,2004). The samples were collected from the Huangbanji-gou section (N 41°36′52.8″, E 120°48′56.8″), the Sihetunsection (N 41°34′52.6″, E 120°46′23.4″), and theZhuanchengzi section (N 41°42′33.7″, E 121°19′11.9″)of the Yixian Formation (Fig. 1). The samples fromHuangbanjigou are dark gray basalts containing olivineand plagioclase phenocrysts. Samples SHT-3 and SHT-14are basalts from Sihetun, dark gray and massive, and theyconsist of orthopyroxene, plagioclase, and sparse olivinephenocrysts. The andesite samples from Zhuanchengziare gray but lack of orthopyroxene and plagioclasephenocrysts.

Fig. 3. 40Ar/39Ar age spectrum and isochron plots for s

The Zhanglaogongtun Formation (Fig. 2b), definedby Wang et al. (1989), consists of basalts and inter-mediate-acidic volcanic rocks. The basalt samples (JG-1,2, 3 and WHC-2) of the Zhanglaogongtun Formationwere collected from Jianguo (N 42°16′42.9″, E 121°54′15.3″) and Wuhuanchi (N 42°18′29.9″, E 121°53′39.8″),respectively. All these rocks are dark gray and massivewith well-developed columnar jointing (Zhang et al.,2003).

3. Analytical methods

The geochronological study was conducted usingthe Ar–Ar dating method for basalts and the SHRIMPU–Pb zircon dating method for andesites and tuffs. ForAr–Ar dating, the rocks were crushed and sieved. Therock fractions without olivine phenocrysts (mesh 40–60 (230 to 380 μm)) were selected by handpicking, andthen the selected sample was washed for several timesin distilled water in an ultrasonic cleaner. Only freshgroundmass was separated from cleaned fractions. Thegroundmass samples were irradiated in a fast neutronflux at the Chinese Academy of Atomic Energy. After3 months, the irradiated samples were incrementally

ample HFG-13 (a and b) and WHC-2 (c and d).

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heated at the temperatures of 700–1500 °C by 18–20steps in a high-vacuum argon extraction system at theLaboratory of Ar–Ar Dating, Institute of Geology andGeophysics, the Chinese Academy of Sciences(IGGCAS). Then, the purified argon was analyzed onthe VG-5400 gas mass spectrometer. The results of40Ar/39Ar dating are presented in Supplementary Table1 and Fig. 3.

Zircons from the tuff and andesite samples wereseparated using gravitational and magnetic sorting, andthen they were handpicked under a binocular micro-scope. Measurements of U, Th, and Pb of zircons wereconducted using the SHRIMP II ion microprobe at theBeijing Center of Ion Microprobe Analysis, China,following the procedure outlined by Williams andClaesson (1987) and Song et al. (2002). The 206Pb/238Uratios were corrected using the zircon standards ofCL13 (572Ma) from Cililanca and TEM (417Ma) fromAustralia. The analytical spot size is 40 μm in averagediameter during each analytical run. Each spot wasrastered over 80 μm for 3 min prior to analysis (5 massscans) to remove common Pb on the surface orcontamination from the gold coating. One spot on thestandard zircon (TEM) was analyzed after every threeanalyses of sample-spots. Squid and Isoplot programsof Ludwig (2001) were used for data processing and agecalculation. The final age results are the weighted meanof the 206Pb/238U ages because 206Pb/238U ages aremore precise than 207Pb/235U ages and 207Pb/206Pbages for young zircons. The common lead is correctedby assuming 206Pb/238U–208Pb/232Th age-concor-dance. Errors on individual spots are based on countingstatistics and are at the 1σ level, but the averageweighted ages are quoted at 2σ or 95% confidence. Theanalytical results are listed in Supplementary Table 2and plotted on the concordia diagrams in Fig. 4.

Major elements compositions of all samples exceptXLG-4 were determined using the Vista ICP-AES at theGuangzhou Institute of Geochemistry, Chinese Acad-emy of Sciences (GIGCAS). The major elementscompositions (Supplementary Table 3) of one tuffsample (XLG-4) for zircon U–Pb dating were deter-mined using wet chemical techniques at the HebeiInstitute of Regional Geology and Mineral Resources.Analytical uncertainties for the majority of majorelements were estimated to be less than 1%. Whole-rock trace elements were analyzed with the inductivelycoupled plasma-mass spectrometry (ICP-MS) at theGIGCAS. The whole-rock powders (50 mg) weredissolved in HF+HNO3 in 15 ml Teflon screw-capcapsules at 100 °C for 1 day, dried to expel most of silicaand then dissolved with HF+HNO3 at 100 °C again for

7–10 days till completely dissolved. Dissolved sampleswere diluted to 50 ml using 1% HNO3 before ICP-MSanalyses. Six standards (GSR-1, GSR-2, GSR-3, MRG-1, W-2, and AGV-2) were analyzed using the sameprocedure to monitor the analytical reproducibility. Themeasured values of the standards are in satisfactoryagreement with the reference values (SupplementaryTable 4). Analytical procedures and precision have beendescribed in detail in Liu et al. (1996). The major andtrace elements data are listed in Table 2.

About 100–150 mg whole rock powder wascompletely decomposed in a mixture of HF-HClO4

for Sr–Nd isotopic analysis and in a mixture of HF-HNO3 for Pb isotopic analysis. For Rb–Sr and Sm–Ndisotope analyses, sample powders were spiked withmixed isotope tracers, dissolved in Teflon capsules withHF+HNO3 at 100 °C for 7–10 days. For Pb isotopedetermination, powder was weighed into the Tefloncapsules and dissolved in HF+HNO3 at 100 °C for 7–10 days. Sr and rare earth elements (REE) wereseparated on quartz columns with a 5 ml resin bed ofAG 50W-X12 (200–400mesh). Nd was separated fromother REEs on quartz columns using 1.7 ml Teflon®powder as cation exchange medium. Pb was separatedon Teflon® columns containing ∼80 μl AG1-X8, 100–200 mesh by employing HBr–HCl wash and elutionprocedure. Procedural blanks were b200 pg for Sr andb50 pg for Pb and Nd. For the measurement of isotopiccompositions, Pb was loaded with a mixture of Si-geland H3PO4 onto a single-Re filament and measured at1300 °C; Sr was loaded with a Ta-HF activator on asingle W filament; and Nd was loaded as phosphatesand measured in a Re-double-filament configuration.143Nd/144Nd ratios were normalized to 146Nd/144Nd=0.7219 and 87Sr/86Sr ratios to 86Sr/88Sr=0.1194. Pbstandard NBS 981 was used to determine thermalfractionation and measured isotopic ratios of sampleswere corrected with a value of 0.1% per atomic massunit. Sr–Nd–Pb isotopic ratios were measured on aFinnigan MAT-262 thermal ionization mass spectrom-eter (TIMS) in the Laboratory for Radiogenic IsotopeGeochemistry, Institute of Geology and Geophysics,Chinese Academy of Sciences, Beijing. Raw dataobtained were calculated using the Isoplot program(Ludwig, 2001), giving 2σm error. Analyses ofstandards during the period of analysis are as follows:NBS987 gave 87Sr/86Sr=0.710254±12 (n=27, 2σ);JMC and AMES gave 143Nd/144Nd=0.511987±7(n=8, 2σ) and 0.512145±12 (n=15, 2σ), respectively.Details of chemical separation and measurement aredescribed in Chen et al. (2000, 2002). The Sr–Nd–Pbisotopic data are listed in Table 3.

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4. Results

Since the Yixian Formation (126Ma–120Ma) has beenwell dated by zircon U–Pb and Ar–Ar methods as

Fig. 4. U–Pb zircon concordia diagrams for samples XLG-4 (a), DHG-1 (c), Dimages of the zircons in XLG-4 (b), DHG-1 (d) and DHG-2 (f). The excludedcircles in the CL images indicate the positions of the analyzed spots. The(Supplementary Table 2) and cannot be displayed in CL images.

mentioned above (Swisher et al., 1999, 2001; Wang et al.,2001a,b; Ji et al., 2004; Yang et al., 2007), the geochrono-logical study of this paper only focuses on the timing of theXinglonggou, Lanqi and Zhanglaogongtun Formations.

HG-2 (e), HFG-27 (g) and HFG-29 (h) and cathodoluminescence (CL)spot analyses are shown with shading error ellipses in (a) and (c). Thezircons in HFG-27 and HFG-29 have very high U and Th contents

Table 2Major oxides (wt.%) and trace elements (ppm) of the Mesozoic volcanic lavas from Western Liaoning

Xinglonggou Formation Lanqi Formation

XLG-1 HFG-13 HFG-15 LQ-6 LQ-9 LQ-10 LQ-11 LQ-15 LQ-16 LQ-17

Andesite Basalt Basalt Basaltic andesite Rhyolite Rhyolite Rhyolite Andesite Andesite Andesite

Sample site N 41°46′32″ E 120°38′34″ N 41°50.484′ E 120°46.009′

SiO2 63.56 53.24 52.37 54.90 65.26 65.86 64.40 56.24 57.04 55.92TiO2 0.58 1.09 1.02 1.16 0.50 0.50 0.57 1.37 1.38 1.40Al2O3 14.94 18.28 16.5 18.51 16.27 16.27 16.76 17.00 17.06 17.05Fe2O3 4.25 8.83 8.47 5.88 4.73 4.29 4.66 7.45 7.27 6.9MnO 0.05 0.14 0.19 0.10 0.06 0.06 0.03 0.13 0.13 0.17MgO 2.85 3.16 1.61 3.90 0.24 0.24 0.42 1.83 1.38 2.30CaO 3.46 6.86 8.19 4.42 1.67 1.75 1.54 4.84 4.88 5.17Na2O 3.52 3.99 3.98 4.69 4.55 4.62 4.62 4.45 4.45 4.40K2O 3.26 1.74 2.69 2.25 4.96 4.96 4.88 3.05 3.32 3.08P2O5 0.21 0.33 0.26 0.35 0.19 0.18 0.20 0.64 0.64 0.69LOI 3.00 1.61 4.96 4.02 1.57 1.31 1.84 2.87 2.47 3.14Total 99.68 99.26 100.23 100.18 100.01 100.04 99.92 99.87 100.02 100.22Mg# 57 42 28 57 9 10 15 33 28 40Sc 8.7 17.3 18.2 20.0 6.5 6.6 7.0 13.2 13.2 13.8Cr 156 2.35 5.33 6.85 0.35 1.19 0.10 ⁎ 0.45 0.03Ni 82.2 5.30 9.16 10.3 ⁎ 5.13 ⁎ 5.10 ⁎ 9.64Rb 113 35.1 76.0 36.9 162 163 159 88.4 110 95.2Sr 461 658 460 444 295 305 355 541 558 576Y 12.7 20.9 18.2 21.1 36.3 38.5 35.5 42.1 39.6 41.1Zr 164 163 130 131 440 442 439 311 311 317Nb 6.0 8.7 8.4 6.0 23.5 23.9 24.0 18.9 19.6 20.0Ba 719 621 1201 822 1318 1288 1340 992 1079 1048Hf 3.9 3.9 3.4 3.2 11.7 11.75 11.5 8.46 8.45 8.61Ta 0.42 0.52 0.48 0.28 1.15 1.17 1.16 0.89 0.94 0.97Pb 17.5 6.2 6.8 8.0 27.0 24.1 24.3 17.1 15.6 15.4Th 11.2 1.97 1.58 1.51 10.0 10.37 9.93 6.82 6.78 7.07U 2.75 0.403 0.343 0.314 2.11 2.33 1.93 1.58 1.61 1.57La 26.2 23.2 20.2 21.0 65.7 65.6 62.8 60.6 56.9 57.2Ce 45.9 51.6 43.0 46.0 109 107 104 119 120 99.9Pr 5.73 6.65 5.67 5.97 15.5 15.5 14.9 15.9 15.3 15.4Nd 20.5 28.0 23.9 23.9 53.7 54.2 52.1 60.5 57.6 59.0Sm 3.82 5.40 4.86 5.11 9.58 9.58 9.13 11.6 11.0 11.4Eu 1.02 1.59 1.48 1.46 1.81 1.80 1.79 2.52 2.43 2.47Gd 3.26 4.94 4.58 4.58 8.06 8.31 7.59 9.99 9.50 9.72Tb 0.421 0.75 0.69 0.668 1.10 1.12 1.03 1.34 1.28 1.32Dy 2.12 4.19 3.83 3.61 5.87 6.09 5.56 7.07 6.77 7.00Ho 0.42 0.80 0.75 0.765 1.25 1.28 1.18 1.47 1.38 1.43Er 1.01 2.13 1.89 1.83 3.28 3.35 3.12 3.66 3.45 3.57Tm 0.152 0.328 0.292 0.279 0.549 0.548 0.524 0.570 0.531 0.558Yb 0.97 2.04 1.85 1.73 3.70 3.70 3.57 3.68 3.44 3.57

96W.Yang,

S.Li/Lithos

102(2008)

88–117

Lu 0.143 0.320 0.300 0.244 0.559 0.547 0.542 0.544 0.501 0.532Sr/Y 36.3 31.43 25.3 21.0 8.13 7.92 10.0 12.9 14.11 14.0Ce/Pb 2.62 8.29 6.28 5.76 4.04 4.44 4.28 6.96 7.69 6.49(La/Yb)N 18.6 7.88 7.58 8.40 12.3 12.3 12.2 11.4 11.5 11.1

Lanqi Formation Yixian Formation

LQ-18 LQ-19 LQ-20 LQ-21 LQ-22 LQ-27 LQ-28 LQ-29 HBJ4-1 HBJ4-2

Andesite Andesite Andesite Andesite Andesite Rhyolite Rhyolite Rhyolite basalt basalt

Sample site N 41°36′52.8″ E120°48′56.8″

SiO2 56.46 56.16 57.96 56.86 56.92 65.62 66.06 66.14 54.83 53.16TiO2 1.44 1.35 1.44 1.42 1.43 0.47 0.47 0.48 0.86 0.9Al2O3 16.95 16.93 17.02 17.41 17.26 16.59 16.57 16.44 15.22 15.71Fe2O3 7.81 6.93 7.07 7.93 7.69 3.9 3.24 3.46 7.88 8.11MnO 0.08 0.11 0.09 0.07 0.09 0.09 0.12 0.08 0.10 0.11MgO 1.50 2.34 1.14 0.78 1.59 0.33 0.69 0.69 6.45 6.23CaO 4.79 5.21 4.17 4.38 4.54 2.17 2.08 2.29 6.73 7.16Na2O 4.62 4.29 4.55 4.55 4.35 5.10 5.00 5.20 3.79 4.18K2O 3.30 3.12 3.50 3.62 3.32 3.88 3.70 3.62 1.65 1.92P2O5 0.71 0.65 0.66 0.67 0.68 0.15 0.17 0.17 0.34 0.36LOI 2.34 3.12 2.14 2.07 2.41 1.33 1.51 1.44 2.08 2.29Total 100.00 100.21 99.74 99.76 100.28 99.63 99.61 100.01 99.93 100.13Mg# 28 40 24 16 29 14 30 29 62 61Sc 13.4 13.3 13.6 13.8 13.5 3.50 3.61 3.28 22.53 21.62Cr 0.64 ⁎ ⁎ ⁎ 0.20 0.30 0.18 ⁎ 292.4 295.6Ni 6.79 6.38 0.81 ⁎ 13.0 1.23 1.66 ⁎ 104.3 105.8Rb 102 95.2 109 129 112 105 100 89.5 41.89 40.72Sr 544 571 547 554 555 415 392 387 848 840Y 39.7 39.6 40.2 41.8 43.0 28.4 27.8 28.0 16.5 16.2Zr 309 313 318 322 313 283 276 270 154 153Nb 19.7 19.8 20.2 20.3 19.9 11.5 11.4 11.1 17.5 17.4Ba 1117 1038 1187 1246 1101 1246 1225 1140 767 752Hf 8.60 8.56 8.50 8.57 8.63 6.47 6.33 6.17 3.48 3.49Ta 0.961 0.966 0.958 0.954 0.963 0.533 0.530 0.511 1.02 1.07Pb 17.4 15.1 17.9 16.9 16.8 15.9 15.0 14.7 9.85 9.67Th 6.89 6.91 6.94 6.97 6.94 4.85 4.77 4.57 4.19 4.20U 1.51 1.49 1.59 1.49 1.59 0.730 0.749 0.731 0.909 0.909La 57.9 56.9 57.5 58.5 61.8 43.4 42.3 41.0 26.4 25.8Ce 120 119 118 106 123 77.8 80.3 78.9 54.6 54.1Pr 15.5 15.3 15.3 15.5 16.3 10.3 9.87 9.54 6.71 6.51Nd 58.9 58.2 58.0 58.9 62.3 37.0 35.1 33.8 25.9 25.5Sm 11.4 11.2 11.1 11.4 12.01 6.725 6.31 6.04 4.58 4.48

(continued on next page) 97W.Yang,

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88–117

Eu 2.49 2.41 2.46 2.50 2.67 1.63 1.56 1.50 1.31 1.32Gd 9.66 9.32 9.59 9.72 10.39 5.79 5.48 5.27 3.87 3.84Tb 1.31 1.28 1.29 1.31 1.41 0.807 0.762 0.734 0.58 0.59Dy 6.87 6.72 6.77 6.92 7.46 4.44 4.16 4.09 3.18 3.19Ho 1.42 1.40 1.39 1.42 1.54 0.961 0.907 0.892 0.611 0.606Er 3.52 3.46 3.44 3.53 3.83 2.46 2.42 2.36 1.62 1.58Tm 0.545 0.539 0.528 0.550 0.598 0.411 0.403 0.396 0.239 0.240Yb 3.54 3.52 3.40 3.56 3.87 2.77 2.77 2.65 1.55 1.53Lu 0.514 0.514 0.494 0.520 0.577 0.414 0.420 0.404 0.241 0.253Sr/Y 13.7 14.4 13.6 13.2 12.9 14.6 14.1 13.8 51.3 51.7Ce/Pb 6.89 7.88 6.59 6.27 7.32 4.89 5.35 5.36 5.54 5.59(La/Yb)N 11.3 11.1 11.7 11.3 11.0 10.8 10.5 10.7 11.7 11.6

Yixian Formation Zhanglaogongtun Formation

HBJ4-3 SHT-14 SHT-3 ZCZ1-1 ZCZ1-2 ZCZ1-3 ZCZ1-4 JG-1 JG-2 JG-3

Basalt Basaltic andesite Basaltic andesite Andesite Andesite Andesite Andesite Basalt Basalt Basalt

Sample site N 41°36′52.8″ E 120°48′56.8″ N 41°34′52.6″ E 120°46′23.4″ N 41°42′33.7″ E 121°19′11.9″ N 42°16′42.9″ E 121°54′15.3″

SiO2 52.84 55.78 56.67 60.19 59.84 61.67 62.17 45.18 44.63 45.19TiO2 0.89 1.1 0.74 0.77 0.76 0.74 0.74 2.97 2.96 2.97Al2O3 15.6 15.47 15.04 15.17 14.96 14.51 14.53 14.98 14.94 15Fe2O3 8.33 7.9 6.26 5.66 5.17 5.25 5.21 11.79 11.64 11.77MnO 0.09 0.11 0.09 0.09 0.08 0.07 0.07 0.17 0.17 0.17MgO 7.03 5.21 5.92 3.3 3.36 3.77 3.58 8.4 8.52 8.49CaO 7.17 5.92 5.36 4.14 4.24 3.82 3.83 10.39 10.27 10.38Na2O 4.13 4.06 4.26 3.52 3.71 3.65 3.63 2.98 3.06 3K2O 1.91 2.4 2.66 2.68 3.19 3.09 3.1 1.37 1.37 1.37P2O5 0.36 0.55 0.46 0.22 0.23 0.21 0.23 0.63 0.63 0.61LOI 2.34 2.36 2.63 4.05 4.53 3.05 3.68 1.35 1.35 1.42Total 100.71 100.87 100.07 99.78 100.07 99.83 100.77 100.21 99.54 100.37Mg# 63 57 65 54 57 59 58 59 59 59Sc 21.7 14.8 15.0 12.4 11.6 11.9 12.0 25.1 24.5 24.1Cr 300 193 320 171 174 175 179 207 204 201Ni 112 117 208 107 95.6 102 107 162 162 162Rb 41.6 40.2 71.8 93.9 96.1 95.9 97.9 48.9 47.8 49.6Sr 847 1046 899 560 568 560 574 769 771 727Y 16.2 15.7 12.6 12.6 12.5 12.0 12.1 26.0 25.6 25.4

Lanqi Formation Yixian Formation

LQ-18 LQ-19 LQ-20 LQ-21 LQ-22 LQ-27 LQ-28 LQ-29 HBJ4-1 HBJ4-2

Andesite Andesite Andesite Andesite Andesite Rhyolite Rhyolite Rhyolite basalt basalt

Sample site N 41°36′52.8″ E120°48′56.8″

Table 2 (continued )98

W.Yang,

S.Li/Lithos

102(2008)

88–117

Zr 152 223 198 208 212 209 209 251 247 246Nb 16.6 11.2 9.64 17.2 17.9 16.8 12.0 58.4 58.3 57.2Ba 771 1062 1078 955 997 984 988 763 754 745Hf 3.45 4.88 4.52 4.73 4.90 4.81 4.84 5.50 5.57 5.57Ta 0.96 0.69 0.65 1.04 1.01 0.91 0.74 3.70 4.01 3.98Pb 10.3 11.5 14.4 15.1 15.5 15.3 15.3 3.12 3.12 3.31Th 4.26 5.68 6.88 7.47 7.69 7.48 7.49 5.45 5.69 5.72U 0.90 1.11 1.54 1.48 1.54 1.46 1.48 1.34 1.37 1.35La 26.3 45.8 34.8 36.3 37.0 36.6 36.4 41.2 40.9 41.1Ce 54.9 93.8 69.2 70.5 71.4 70.4 71.4 82.7 81.7 82.8Pr 6.70 11.4 8.12 7.82 8.02 7.97 7.99 10.2 10.0 10.2Nd 26.1 43.5 30.3 28.8 29.4 28.7 28.8 41.1 40.9 41.6Sm 4.54 6.72 4.87 4.68 4.65 4.63 4.52 8.11 7.98 8.06Eu 1.32 1.82 1.29 1.18 1.22 1.19 1.20 2.48 2.51 2.55Gd 3.85 4.74 3.64 3.59 3.37 3.50 3.38 7.43 7.24 7.38Tb 0.594 0.692 0.506 0.520 0.516 0.512 0.499 1.10 1.08 1.08Dy 3.24 3.41 2.67 2.71 2.65 2.62 2.64 5.71 5.65 5.73Ho 0.62 0.60 0.47 0.47 0.47 0.47 0.47 1.01 1.01 1.04Er 1.64 1.61 1.22 1.26 1.25 1.23 1.23 2.50 2.53 2.57Tm 0.23 0.23 0.18 0.18 0.17 0.17 0.18 0.36 0.36 0.35Yb 1.59 1.44 1.22 1.13 1.13 1.16 1.15 2.19 2.21 2.20Lu 0.254 0.219 0.189 0.181 0.183 0.187 0.182 0.338 0.335 0.342Sr/Y 52.2 66.4 70.9 44.3 45.4 46.4 47.3 29.5 30.0 28.6Ce/Pb 5.32 8.12 4.80 4.64 4.59 4.59 4.64 26.4 26.2 25.0(La/Yb)N 11.4 21.9 19.7 22.1 22.6 21.8 21.9 13.0 12.7 12.9

Zhanglaogongtun Formation

JG-4 JG-5 WHC-1 WHC-2 WHC-3 WHC-4

Basalt Basalt Basalt Basalt Basalt Basalt

Sample site N 42°16′42.9″ E 121°54′15.3″ N 42°18′29.9″ E 121°53′39.8″

SiO2 43.89 45.75 43.57 42.71 43.37 43.31TiO2 2.98 2.96 2.99 2.96 2.97 2.94Al2O3 15.2 15.06 15.14 14.88 15.12 14.99Fe2O3 11.85 11.63 12.32 12.22 12.18 11.9MnO 0.18 0.17 0.18 0.17 0.18 0.17MgO 8.86 8.36 8.43 8.39 8.54 8.32CaO 10.46 10.22 9.76 9.67 9.78 9.5Na2O 3.33 3.04 3.91 3.76 3.95 3.94K2O 1.46 1.4 0.8 0.7 0.74 0.76P2O5 0.65 0.62 0.73 0.71 0.71 0.71LOI 1.57 1.38 2.57 3.19 3.17 2.71Total 100.42 100.59 100.38 99.35 100.7 99.26Mg# 60 59 58 58 58 58

(continued on next page) 99W.Yang,

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88–117

Sc 24.2 23.5 22.2 22.4 22.0 21.7Cr 213 200 148 152 158 146Ni 163 157 130 131 137 130Rb 50.4 49.0 14.8 10.7 9.86 12.4Sr 760 776 772 768 734 767Y 25.6 25.2 26.0 26.1 25.8 26.4Zr 245 245 249 250 249 254Nb 59.9 57.8 58.5 58.3 59.0 60.4Ba 771 752 742 856 795 754Hf 5.55 5.45 5.51 5.67 5.69 5.60Ta 3.74 3.77 3.77 3.74 3.73 3.87Pb 3.07 3.20 3.14 3.36 3.14 3.44Th 5.71 5.55 5.58 5.73 5.80 5.80U 1.39 1.37 1.45 1.39 1.40 1.47La 42.1 40.6 41.7 42.3 42.5 42.8Ce 83.0 82.2 83.4 85.4 85.6 86.4Pr 10.2 10.1 10.4 10.5 10.7 10.8Nd 41.0 41.0 42.8 42.9 43.4 43.7Sm 8.04 7.91 8.25 8.52 8.53 8.39Eu 2.50 2.45 2.59 2.61 2.68 2.65Gd 7.45 7.22 7.54 7.72 7.69 7.61Tb 1.07 1.07 1.14 1.14 1.12 1.14Dy 5.61 5.76 5.93 5.89 6.02 5.88Ho 1.00 1.03 1.06 1.06 1.06 1.07Er 2.49 2.47 2.60 2.60 2.58 2.58Tm 0.35 0.35 0.36 0.36 0.36 0.36Yb 2.21 2.18 2.29 2.29 2.30 2.34Lu 0.34 0.33 0.34 0.34 0.36 0.36Sr/Y 29.6 30.6 29.6 29.3 28.4 28.9Ce/Pb 26.9 25.6 26.5 25.4 27.2 25.0(La/Yb)N 13.1 12.8 12.5 12.7 12.7 12.6

LOI = loss on ignition; Mg#=Mg/(Mg+TFeO) atomic ratio. “⁎” stands for non-detective.

Table 2 (continued )

Zhanglaogongtun Formation

JG-4 JG-5 WHC-1 WHC-2 WHC-3 WHC-4

Basalt Basalt Basalt Basalt Basalt Basalt

Sample N 42°16′42.9″ E 121°54′15.3″ N 42°18′29.9″ E 121°53′39.8″

100W.Yang,

S.Li/Lithos

102(2008)

88–117

101W. Yang, S. Li / Lithos 102 (2008) 88–117

4.1. Geochronology

4.1.1. The Xinglonggou FormationFig. 4a show the SHRIMP U–Th–Pb analytic results

on 15 spots of zircons from the tuff sample (XLG-4). Themajor element compositions (Supplementary Table 2) ofthe tuff sample (XLG-4) are similar to those of granitesor rhyolites, suggesting that the tuff mainly consists ofvolcanic materials, while its high Fe2O3/FeO and HO2

+

contents indicate its surface deposit environment. Theanalysis of XLG-4-13 gives an apparently higher206Pb/238Pb age (240.6±3.4 Ma) and U (206 ppm),Th (149 ppm) contents than those given by other zir-cons (Supplementary Table 2), suggesting that thiszircon grain is different in origin from other zircons. Thecathodoluminescence (CL) images also show thedeference between zircon grain XLG-4-13 and theothers, i.e., the former is characterized by oscillatoryzoning with no fan-structure and others are characterizedby oscillatory zoning with well-developed fan-structure(Fig. 4b). The analysis of XLG-4-16 also gave anapparently higher 206Pb/238Pb age (205.7±7.3 Ma) thanthose of other zircons. The age of XLG-4-16 could be inerror because of its very low radiogenic Pb content(0.7 ppm) (Supplementary Table 2). Therefore, theanalyses of XLG4-13 and XLG4-16 are excluded fromthe calculation of the weighted mean age. The remaining13 analyses give a weighted mean 206Pb/238Pb age of176.7±3.5 Ma. This age is slightly younger than theprevious reported Ar–Ar ages of 188–194 Ma for theXinglonggou andesites (Chen et al., 1997), but signifi-cantly older than the U–Pb SHRIMP age of theXinglonggou rhyolites (159±3 Ma) reported by Gaoet al. (2004).

4.1.2. The Lanqi FormationFive samples (DHG-1,DHG-2,HFG-13, HFG-27, and

HFG-29) from this formation have been dated. Fig. 4cshow the SHRIMP U–Th–Pb analytic results on 10 spotsof zircons from the tuff sample (DHG-1), which given anage of 164.1±2.4 with a relative high MSWD (meansquare of weighted deviation) value of 3.5. Since theanalysis of DHG1-9 gives an apparently lower206Pb/238Pb age than those given by other zircons, whenit was excluded from the calculation of the weightedmeanage, the remaining 9 analyses give a weighted mean206Pb/238Pb age of 165.0±1.2 Ma with a relative smallerMSWD value of 1.5.

Fig. 4e shows the SHRIMP results on 10 spots ofzircons from the andesite sample (DHG-2). They yield amean age of 164.3±2.2 Ma. This age is consistent withthe SHRIMP zircon U–Pb age of 165.0±1.2 Ma for

sample DHG-1 and the Ar–Ar ages of 165 to 159 Ma forsamples from the same locality (Chen et al., 2004; Heet al., 2004).

Fig. 3a–b shows the 40Ar/39Ar spectra with plateauage and isochron plot of basalt sample HFG-13. Allerrors are reported at the 2σ level. This sample yields the40Ar/39Ar plateau age of 166.1±0.9 Ma, which isdefined by 92.2% of total released 39Ar. The isochrondiagram (Fig. 3b) indicates an age of 166.7±2.9 Maand an initial 40Ar/36Ar ratio of 290.9±16.5, which areconsistent with its plateau age and the present at-mospheric 40Ar/36Ar ratio (295.5), suggesting that ex-cess argon is insignificant and the plateau or isochron ageis reliable.

The analytical results on 11 spots of zircons fromrhyolite sample HFG-27 are shown on Fig. 4g. Theyyield a weighted mean 206Pb/238Pb age of 160±6 Ma.

The analytical results on 16 spots of zircons fromandesite porphyrite HFG-29 (intruded into the LanqiFormation) are shown on Fig. 4h. They give a mean ageof 153±2 Ma, which may indicate the last activity of theLanqi magmatism.

4.1.3. The Zhanglaogongtun FormationFig. 3c–d shows the 40Ar/39Ar spectra with plateau

age and isochron plot of WHC-2. The sample yields the40Ar/39Ar plateau age of 106.1±0.8 Ma, which is definedby 89.1% of total released 39Ar. The isochron diagram(Fig. 3d) indicates an age of 105.1±1.3 Ma and an initial40Ar/36Ar ratio of 306.6±21.5, consistent with its plateauage and the present atmospheric 40Ar/36Ar ratio (295.5).This suggests that the excess argon is minimal and theplateau age is reliable. The plateau age is consistentwith the previously reported Ar–Ar and K–Ar ages of ca.109–93 Ma (Zhang et al., 2003; Zhu et al., 2002).

4.2. Geochemistry

4.2.1. Xinglonggou andesiteBecause geochemistry of the Xinglonggou andesite

has been well studied (Gao et al., 2004; Li, 2006), onlyone Xinglonggou andesite sample (XLG-1) was analyzedfor major-trace element and Sr–Nd–Pb isotopic composi-tions. Sample XLG-1 is characterized by high SiO2

(63.56 wt.%) and Al2O3 (14.94 wt.%), high Mg# (57), Cr(156 ppm), and Ni (82.2 ppm) contents (Table 2). It is alsoenriched in light rare-earth elements (LREE), LILE, andPb, and depleted in HFSE, heavy rare-earth elements(HREE), and Y. It has high Sr/Y (36.3) and (La/Yb)N(18.6, where subscript N denotes C1-chondrite normal-ization) without negative Eu anomaly (Table 2; Fig. 6).This sample has moderate 87Sr/86Sr (0.70660), slightly

Table 3Sr–Nd–Pb isotopes of the Mesozoic volcanic rocks from Western Liaoning

87Rb/86Sr 87Sr/86Sr 87Sr/86Sr(t)

147Sm/144Nd 143Nd/144Nd 143Nd/144Nd(t)

ɛNd(t) 206Pb/204Pb 207Pb/204Pb 208Pb/204Pb 206Pb/204Pb(t)

207Pb/204Pb(t)

208Pb/204Pb(t)

Xinglonggou Fm. XLG-1

0.2767 0.707218 0.706597 0.0971 0.512459 0.512357 −1.5 18.471 15.567 38.520 18.211 15.554 38.176

Lanqi Fm. HFG-13

0.1374 0.706565 0.706247 0.1228 0.511969 0.511836 −11.5 16.485 15.253 36.619 16.385 15.249 36.459

HFG-15

0.1393 0.706565 0.706242 0.1210 0.511940 0.511809 −12.0 16.477 15.254 36.616 16.400 15.250 36.499

LQ-6 0.0507 0.706707 0.706593 0.1234 0.511970 0.511841 −11.5 16.502 15.271 36.639 16.441 15.268 36.543LQ-9 2.5478 0.710065 0.704344 0.1068 0.511921 0.51181 −12.1 16.582 15.297 36.792 16.460 15.291 36.602LQ-10 2.2643 0.710041 0.704956 0.1076 0.511930 0.511818 −12.0 16.594 15.273 36.740 16.443 15.265 36.521LQ-15 0.1390 0.707242 0.70693 0.1035 0.511965 0.511856 −11.2 16.762 15.330 36.978 16.616 15.323 36.773LQ-16 0.1881 0.707431 0.707008 0.1026 0.511947 0.511839 −11.6 16.786 15.334 37.001 16.624 15.326 36.778LQ-17 0.1450 0.707352 0.707026 0.0924 0.511934 0.511837 −11.6 16.767 15.320 36.960 16.607 15.312 36.725LQ-18 0.2252 0.707466 0.706961 0.1002 0.511956 0.511851 −11.3 16.744 15.307 36.898 16.608 15.300 36.696LQ-19 0.1481 0.707304 0.706971 0.0924 0.511967 0.51187 −11.0 16.760 15.310 36.929 16.605 15.303 36.695LQ-20 0.3219 0.707449 0.706726 0.1050 0.511958 0.511848 −11.4 16.754 15.326 36.954 16.614 15.320 36.756LQ-21 0.3500 0.707612 0.706826 0.0950 0.511935 0.511835 −11.6 16.745 15.294 36.862 16.607 15.287 36.652LQ-22 0.2662 0.707441 0.706843 0.0953 0.511981 0.511881 −10.7 16.733 15.285 36.828 16.585 15.277 36.617LQ-27 1.3529 0.708640 0.705602 0.1172 0.511852 0.511729 −13.7 16.179 15.210 36.791 16.108 15.207 36.636LQ-28 1.6876 0.708662 0.704872 0.1145 0.511847 0.511727 −13.8 16.183 15.221 36.840 16.106 15.217 36.679LQ-29 0.7523 0.708556 0.706866 0.0987 0.511847 0.511743 −13.4 16.167 15.194 36.750 16.090 15.191 36.593

Yixian Fm. HBJ4-1

0.1330 0.706475 0.706242 0.1115 0.512025 0.511934 −10.6 16.675 15.272 36.851 16.566 15.267 36.686

HBJ4-2

0.1269 0.706510 0.706287 0.1134 0.511955 0.511862 −12.0 16.669 15.270 36.843 16.558 15.265 36.675

HBJ4-3

0.1452 0.706399 0.706144 0.1114 0.512070 0.511979 −9.7 16.696 15.284 36.891 16.592 15.279 36.731

102W.Yang,

S.Li/Lithos

102(2008)

88–117

87Rb/86Sr 87Sr/86Sr 87Sr/86Sr(t)

147Sm/144Nd 143Nd/144Nd 143Nd/144Nd(t)

ɛNd(t) 206Pb/204Pb 207Pb/204Pb 208Pb/204Pb 206Pb/204Pb(t)

207Pb/204Pb(t)

208Pb/204Pb(t)

SHT-14

0.1054 0.706053 0.705868 0.0970 0.511868 0.511789 −13.4 16.554 15.250 36.789 16.440 15.244 36.599

SHT-3 0.2207 0.707022 0.706635 0.1010 0.511951 0.511868 −11.9 16.779 15.292 36.963 16.651 15.286 36.778ZCZ1-1

0.4778 0.707907 0.707069 0.1001 0.511938 0.511856 −12.1 16.331 15.225 36.550 16.216 15.219 36.361

ZCZ1-2

0.4695 0.707732 0.706908 0.1005 0.511918 0.511836 −12.5 16.358 15.230 36.578 16.242 15.225 36.388

ZCZ1-3

0.5133 0.707577 0.706677 0.1012 0.511900 0.511817 −12.9 16.370 15.230 36.578 16.258 15.224 36.392

ZCZ1-4

0.4562 0.707630 0.706830 0.0997 0.511910 0.511828 −12.7 16.338 15.225 36.562 16.225 15.220 36.375

Zhanglao-gongtunFm.

JG-1 0.1620 0.703754 0.703515 0.1232 0.512831 0.512746 4.75 18.343 15.490 38.331 17.897 15.468 37.736JG-2 0.1776 0.703782 0.703520 0.1232 0.512815 0.512730 4.44 18.328 15.490 38.317 17.871 15.468 37.696JG-3 0.1794 0.703827 0.703563 0.1235 0.512811 0.512726 4.36 18.288 15.471 38.252 17.865 15.451 37.665JG-4 0.1762 0.703725 0.703465 0.1227 0.512830 0.512746 4.74 18.359 15.487 38.341 17.889 15.465 37.709JG-5 0.1822 0.703781 0.703513 0.1232 0.512808 0.512723 4.30 18.286 15.481 38.260 17.841 15.460 37.672WHC-1

0.05359 0.703935 0.703856 0.1218 0.512869 0.512785 5.51 18.440 15.484 38.366 17.957 15.461 37.760

WHC-2

0.03560 0.703692 0.703640 0.1248 0.512883 0.512797 5.74 18.426 15.482 38.366 17.994 15.462 37.785

WHC-3

0.03776 0.703533 0.703477 0.1275 0.512824 0.512736 4.56 18.393 15.481 38.346 17.929 15.458 37.718

WHC-4

0.04183 0.703789 0.703727 0.1223 0.512822 0.512738 4.59 18.427 15.488 38.367 17.981 15.467 37.792

Chondrite Uniform Reservoir (CHUR) values (87Rb/86Sr=0.0847, 87Sr/86Sr =0.7045, 147Sm/144Nd=0.1967, 143Nd/144Nd=0.512638) are used for the calculation. λRb=1.42×10−11 year− 1,

λSm=6.54×10− 12 year−1, λU238=1.55125×10

− 0 year−1, λU235=9.8485×10−10 year−1, λTh232=4.9475×10

−11 year−1 (Steiger and Jager, 1977; Lugmair and Marti, 1978). Initial isotopicratios were calculated by using 177 Ma, 160 Ma, 125 Ma and 106 Ma for the Xinglonggou, Lanqi, Yixian and Zhanglaogongtun lavas, respectively.

103W.Yang,

S.Li/Lithos

102(2008)

88–117

104 W. Yang, S. Li / Lithos 102 (2008) 88–117

negative ɛNd(T) (−1.5), and radiogenic Pb isotopiccompositions (206Pb/207Pb= 18.211, 207Pb/204Pb=15.554, and 208Pb/204Pb=38.176) (Table 3). These

geochemical features are consistent with those of theXinglonggou andesites reported by Gao et al. (2004) andLi (2006).

Fig. 6. Primitive mantle-normalized trace element diagrams for the Mesozoic volcanic rocks. Dash lines represent basalts and basaltic andesites, whilesolid lines represent andesites in figure b and c. Normalization values for primitive mantle are from Sun and McDonough (1989).

105W. Yang, S. Li / Lithos 102 (2008) 88–117

4.2.2. Lanqi lavasThe Lanqi basalts and basaltic andesites have SiO2 of

52∼53 wt.%, high Al2O3 (N16.5 wt.%) and CaO(N6.5 wt.%), low MgO (b3.5 wt.%), Cr (b6 ppm), andNi (b10 ppm) contents (Table 2). They are enriched inLREE and Rb, Ba, Sr, Pb, and depleted in high fieldstrength element, Th, and U (see dash line in Fig. 6b). Thetwo basaltic samples (HFG-13, 15) have moderate87Sr/86Sr (∼0.706), low ɛNd(t) (∼−12), and unradiogenicPb (206Pb/207Pb b16.5, 207Pb/204Pb b15.3, and208Pb/204Pbb36.5) (Table 3). The isotopic compositionsare similar to the EMI-like component (Zindler and Hart,1986).

The Lanqi andesites and rhyolites are characterized bySiO2 of 56∼66 wt.%, high Al2O3 (N16 wt.%), and lowMgO (b2.5 wt.%), Cr (b1 ppm), and Ni (b7 ppm)

Fig. 5. Major oxide variations in theMesozoic volcanic rocks inWestern Liaoniand this paper; Lanqi formation, Li et al. (2004) and this paper; Yixian, Ji et al.Zhang et al. (2003) and this paper. Solid symbols and open symbols represent dvolcanic rocks is based on the total alkali–silica diagram of LeMaitre et al. (198basaltic andesite, andesite and trachyte except some samples from the Xinglongrelative to the others.

concentrations (Table 2). These rocks are enriched inLREE, LILE, and Pb, and depleted inHFSEwith negativeSr and Eu anomalies (Fig. 6b solid line). They havemoderate 87Sr/86Sr (0.704∼0.706), negative ɛNd(T)(−13∼−10), and unradiogenic Pb (206Pb/207Pbb16.6,207Pb/204Pbb15.4, and 208Pb/204Pbb36.8) (Table 3).These isotopic features are similar to the Lanqi basalts,but different with the Xinglonggou andesites. The Lanqiandesites and rhyolites have relatively low MgO but highAl2O3 contents, distinct from the Xinglonggou and theYixian andesites (Fig. 5).

4.2.3. Yixian lavasThe samples from the Yixian Formation exhibit a

wide compositional range with SiO2 varying from 52 to62 wt.%. CaO, Al2O3, TFe2O3, MgO, and P2O5 are

ng. Data source: the Xinglonggou formation, Gao et al. (2004), Li (2006)(2004), Wang et al. (2005), and this paper; Zhanglaogongtun formation,ata from this paper and from the literature, respectively. Classification of9). The Mesozoic volcanic rocks are alkaline and consist of trachy basalt,gou formation. The Lanqi lavas have low MgO and high Al2O3 contents

106 W. Yang, S. Li / Lithos 102 (2008) 88–117

negatively correlated with SiO2 (Fig. 5). They haveenrichments in LREE, LILE, and Pb, and depletion inHFSE. The geochemical characteristics of the Yixianbasalts and basaltic andesites are similar to the Lanqibasaltic rocks except for the higher Ni (N95 ppm) and Cr(N170 ppm) contents in the Yixian basalts.

TheYixian andesites have SiO2%N56wt.%,Al3O2%N15 wt.%, MgOb3 wt.% without negative Eu anomaly.The high Mg# (N54) and Cr (N200 ppm) and Ni(N100 ppm), high Sr (N400 ppm) and Sr/Y (N40), lowYb (b18 ppm) and Y (b1.9 ppm) contents indicate thatthe Yixian andesites are typical high-Mg# adakites. Theyalso show positive Pb and Sr anomalies on the spiderdiagram (Fig. 6c). The Yixian andesites have moderate

Fig. 7. Initial Sr–Nd–Pb isotopic compositions of the Mesozoicvolcanic rocks in Western Liaoning. Data source: lower and uppercrust is after Jahn et al. (1999); MORB, Hofmann (1997); N-MORB,Zindler and Hart (1986); marine sediments/upper crust, White(2005); NHRL stands for Northern Hemisphere Reference Line(Hart, 1984). (207Pb/204Pb)NHRLB=0.1084× (206Pb/204Pb)+13.491;(208Pb/204Pb)NHRL=1.209× (

206Pb/204Pb)+15.627; the Xinglonggouformation: Gao et al. (2004), Li (2006), and this paper; Lanqi formation,Li et al. (2004) and this paper; Yixian, Ji et al. (2004) and this paper;Zhanglaogongtun formation, Zhang et al. (2003) and this paper. Solidsymbols and open symbols represent data from this paper and from theliterature, respectively. Initial isotopic ratios were calculated by using177 Ma, 160 Ma, 125 Ma, and 106 Ma for the Xinglonggou, Lanqi,Yixian, and Zhanglaogongtun lavas, respectively.

87Sr/86Sr (∼0.706), low ɛNd(t) (∼−10), and unradio-genic Pb (206Pb/207Pbb16.6, 207Pb/204Pbb15.3, and208Pb/204Pbb36.8), similar to those of the Lanqi andesites(Fig. 7).

4.2.4. Zhanglaogongtun lavasThe Zhanglaogongtun lavas display a limited com-

positional range with low SiO2 content between 42 and45 wt.%. They have relatively high alkalis (Na2O+K2ON4 wt.%), MgO, TFeO, CaO, TiO2, MnO, andtransitional metal elements (Sc, Cr, Ni) contents (Fig. 5).They are also enriched in LREE and LILE, but withoutdepletion of HFSE. The positive Nb, Ta anomalies andnegative Pb anomalies on the spider diagram distinguishthem from the Lanqi and Yixian lavas. In addition, theyhave low 87Sr/86Sri (b0.704), high ɛNd(T) (N4), andradiogenic Pb (206Pb/207PbN17.8, 207Pb/204PbN15.4,and 208Pb/204PbN37.6), which are similar to theCenozoic basalts from the NCC and oceanic islandbasalts (Zhou and Armstrong, 1982; Peng et al., 1986;Basu et al., 1991).

5. Discussion

5.1. Geochronology of the volcanic rocks

5.1.1. The Xinglonggou FormationThe age of the Xinglonggou Formation is controver-

sial. Chen et al. (1997) reported Ar–Ar ages of 188–194 Ma for the Xinglonggou andesites, while Gao et al.(2004) reported a SHRIMP U–Pb zircon age of 159±3Ma for a rhyolite sample from the Xinglonggou village.The Ar–Ar plateau ages of 188–194 Ma (Chen et al.,1997) are not reliable because the sample has experi-enced significant alteration (Loss on Ignition=8.3%)and the age is defined by only 40% of total released 39Ar.The age of 159 Ma reported by Gao et al. (2004)contradict with the plant fossils recovered from theBeipiao Formation, which overlies the XinglonggouFormation and points to an early Jurassic age (Li, 2006).Actually, the age of 159±3Ma for Xinglonggou rhyoliteis consistent with the age of 160±6 Ma for the Lanqirhyolite reported in this paper. Furthermore, a recent fieldinvestigation demonstrates that the age of 159±3 Mareported by Gao et al. (2004) may indicate the intrusiontime of the rhyolitic dike in the Xinglonggou village, astheir samples were actually collected from a rhyoliticdike rather than any representative rocks from theXinglonggou Formation. Therefore, the SHRIMP U–Pbzircon age of 176.7±3.5 Ma reported in this paper is amore reasonable age for the Xinglonggou Formationthan the literature ages.

Fig. 8. Sr/Y versus Y diagram after Defant et al. (2002), where theadakite area is defined by Sr/YN40 (Martin, 1999; Martin et al., 2005).Most Xinglonggou and Yixian samples have high Sr/Y and La/Yb butlow Y contents similar to typical adakites, while the Lanqi andesiteshave relatively higher Y content and lower Sr/Y. Data source: theXinglonggou formation: Gao et al. (2004), Li (2006), and this paper;Lanqi formation, this paper; Yixian, Ji et al. (2004) and Wang et al.(2005) and this paper; Zhanglaogongtun formation, Zhang et al. (2003)and this paper. Solid symbols and open symbols represent data fromthis paper and from the literature, respectively.

107W. Yang, S. Li / Lithos 102 (2008) 88–117

5.1.2. The Lanqi FormationOur results indicate that the Lanqi lavas erupted from

166 to 153 Ma. These ages are consistent with theprevious reported ages of the Lanqi/Tiaojishan Forma-tion. Zhao et al. (2004) have concluded that the mainvolcanic section of the Tiaojishan and Lanqi Formationsranges in age from 165 to 156 Ma based on thepublished SHRIMP U–Pb and Ar–Ar ages. Davis(2005) suggested that the range of recently published40Ar/39Ar ages is considerably wider and concluded thatthe age of the Lanqi/Tiaojishan Formation is between175 and 148 Ma. Two of their published ages (174–173 Ma) are apparently higher than the others (166–148 Ma). Their older ages were obtained from anandesite that lies unconformably above the Paleozoic orProterozoic strata and they are not surely correlated withthe Tiaojishan and Lanqi formations. Collectively, theseages indicate an age range of ca. 166–148 Ma for theTiaojishan and Lanqi Formations.

5.1.3. The Zhanglaogongtun FormationThe Ar–Ar plateau age of ca. 106 Ma and the

previous reported Ar–Ar and K–Ar ages of ca. 109–93 Ma (Zhang et al., 2003; Zhu et al., 2002) suggest thatthe age of this formation is between 109 and 93 Ma.

5.2. Origin of the Xinglonggou andesites

The Xinglonggou Formation (ca. 177 Ma) consistsmainly of andesites with geochemical features similar tothose of typical adakites: high SiO2 (N56 wt.%), Al2O3

(N15 wt.%), and Sr contents (N400 ppm), high Sr/Y(N40) and La/Yb (N20), and low Yb (b1.9 ppm) and Ycontents (b19 ppm) (Defant and Drummond, 1990; Kayand Kay, 1993; Martin, 1999; Martin et al., 2005). Asshown in Fig. 8, the Xinglonggou andesites have highSr/Y and low Y content similar to other Mesozoicadakites observed in Eastern China, such as Ningzhen(Xu et al., 2002a), Xuzhou–Suzhou (Xu et al., 2006),and low-Mg adakites from the Dabie orogen (Wanget al., 2007; Xu et al., 2007). The high Mg# (57) of theXinglonggou andesite indicates that it is high-Mg#adakite.

Adakites were originally considered to be producedby partial melting of young and hot subducted oceanicslabs (Defant and Drummond, 1990). However, alter-native petrogenetic processes could also produceadakitic rocks, e.g., fractional crystallization of basalticmagmas and assimilation of felsic crustal materials(Castillo et al., 1999), basaltic and felsic magma mixing(e.g., Guo et al., 2007), and partial melting of maficcontinental lower crust that has foundered into the

convecting mantle (e.g., Xu et al., 2002a; Chung et al.,2003; Gao et al., 2004). Experimental studies of partialmelting of basalts at high pressure (N1.2 GPa) show thatgarnet (not plagioclase) can occur as a liquidus phase orresidual mineral in equilibrium with high SiO2 andAl2O3 adakitic melt, resulting in the high Sr and LREE,but low HREE and Y contents which are characteristicfeatures of adakitic magma (e.g., Rapp and Watson,1995; Rapp et al., 1999).

The origin of the Xinglonggou andesites is still indebate. Because of a lack of mafic rocks in theXinglonggou Formation and the high Ni+Cr contentsof the Xinglonggou andesites, it is unlikely that theXinglonggou andesites were produced by assimilationand fractional crystallization (AFC) processes involvingbasaltic magmas or mixing between basaltic and felsicmagmas (Gao et al., 2004). Gao et al. (2004) suggestedthat the Xinglonggou high-Mg# adakites were producedby partial melting of foundered lower continental crust,based on the abundant inherited Archaean zircons in theserocks. However, the following several lines of evidenceargue against the generation of the Xinglonggou high-Mg# adakite by partial melting of the foundered lowercontinental crust. First, the radiogenic Pb isotopiccomposition of the Xinglonggou high-Mg# adakitesreported in Li (2006) and this study may suggest aderivation from partial melting of subducted oceaniccrust, instead of lower continental crust. As shown in

108 W. Yang, S. Li / Lithos 102 (2008) 88–117

Fig. 7b, the 207Pb/204Pbi of the Xinglonggou high-Mg#adakites are higher than those of both the lowercontinental crust and N-MORB, but they are similar tothat of the upper continental crust and the marinesediments. Thus, reactions between melt derived fromthe lower continental crust and the mantle cannot producesuch radiogenic Pb isotopic compositions of the Xin-glonggou high-Mg# adakites. Second, the ɛNd(T) valuesand initial 87Sr/86Sr ratios of theXinglonggou adakites areunlikely to be produced by reactions of partial melts fromthe foundered eclogitic lower continental crust withmantle peridotite, either. Gao et al. (2004) suggestedthat the Sr–Nd isotopic compositions of the Xinglonggouadakites could be interpreted as a result of mixing of theXuhuai eclogites and whole peridotite of the uppermantle. However, experimental studies show that, duringmelt-peridotite interaction, because olivine is under-saturated in SiO2, the SiO2-rich melt may only assimilateolivine (Rapp et al., 1999, 2005). Considering theextremely low olivine/meltDNd (e.g., 7×10

−5 in Suhr et al.(1998)) and thus lowNd content in olivine, assimilation ofolivine may not significantly change the Nd isotopiccomposition of adakitic melts. Experimental studies alsoshow that while the reaction between melt and olivine canincrease the incompatible element concentrations, but itdoes not significantly modify the ratios between thoseincompatible trace elements (Rapp et al., 1999, 2005).Therefore, assimilation ofmantle olivine by adakiticmeltscannot change either incompatible element ratios (e.g.,LILE/HFSE) or Sr–Nd–Pb isotopic compositions, whilethe highMg, Cr, andNi contents of the high-Mg# adakitesmight result from interaction between silicic melts andmantle peridotite.

In summary, the Sr–Nd–Pb isotopic compositionsand high MgO, Cr, and Ni contents suggest that theXinglonggou high-Mg# adakites are more likely to beproduced by reaction between partial melts fromsubducted oceanic crust and mantle peridotite. Theabundant inherited Archaean zircons may come fromterrigenous sediments carried by subducted oceaniccrust. Such terrigenous sediments, derived from theupper continental crust of the NCC, could containabundant Archaean zircons, and have evolved Sr–Nd–Pb isotopic compositions.

5.3. Origin of the Lanqi lavas

5.3.1. The Lanqi basaltsThe Lanqi basalts have SiO2 of 52–53 wt.%, high

Al2O3 (N16.5 wt.%), CaO (N6.8 wt.%), low MgO(b3.5 wt.%), Cr (b6 ppm), Ni (b10 ppm), Th (b2 ppm),and U (b0.5 ppm) contents, enrichment of LILE and

LREE, and depletion of HFSE, and positive Pb anomaly(Fig. 6). These trace element signatures are similar to arcmagmas or continental crust. It has been suggested thatsuch trace element signatures of arc magmas could reflectthe mantle source metasomatized by slab-derived fluids.Because LREE, LILE, and Pb are more fluid-soluble thanHREE and HFSE (e.g., Brenan et al., 1995; Keppler 1996;Kogiso et al., 1997; Peate et al., 2001; Manning 2004),fluids derived from subducted oceanic crust and sedimentsusually have high LREE/HREE and LILE/HFSE ratiosand positive Pb anomaly as well as high 87Sr/86Sr. Themantle wedge metasomatized by the subducting slab-derived fluids can account for the trace element signaturesof arc lavas, and also increase the Rb/Sr ratios and result inthe EMII isotopic features. However, as shown on Fig. 7,the Lanqi basalts have moderate 87Sr/86Sr, low ɛNd(t), andunradiogenic Pb isotopic ratios. Therefore, it is unlikelythat the Lanqi basalts derived from fluid-metasomatizedmantle because of their EMI-type isotopic features.

The known terrestrial reservoirs able to evolve suchlow 206Pb/204Pb are the ancient (Archaean/Proterozoic)continental lower crust and EMI-type sub-continentallithopheric mantle (e.g., Smoky Butte lamproites, Fraseret al., 1985). The Lanqi basalts are also unlikely to bederived from partial melting of an EMI-type sub-continental lithospheric mantle, because this suggestionrequires that the lithospheric mantle not only preserves alow-μ signature for a long time, but also have higher Ce/Pb ratio (N40). For example, the EMI-type mantlexenoliths discovered in the Tertiary alkaline basalt informthe Taihang region have ɛNd(T) values ranging from −6.9to−10.6 and their Ce/Pb range from 41.5 to 72.0 (Ma andXu, 2006), similar to the Ce/Pb (N40) of the Smoky Buttelamproites with negative Pb anomalies (Fraser et al.,1985). But these features are inconsistent with the Lanqibasalts with positive Pb anomalies and low Ce/Pb ratios(b10). In addition, the unradiogenic Pb isotopes are notconsistent with the observation that the mantle xenolithshosted in the Paleozoic kimberlites from Shandong andeastern Liaoning have EMII-type Sr–Nd isotopic featureswith 206Pb/207Pb varying between 18 and 20 (Zheng andLu, 1999). Indeed, a 206Pb/204Pbi as low as 16.2 incontinental lower crust is most likely related to the timeeffect of U–Th depletion resulting from granulite-faciesmetamorphism (Rollinson, 1993; Rudnick and Fountain,1995). Thus, the lower continental crust of the NorthChina Craton may be important in generating thegeochemical features of the Lanqi basalts.

The contribution of the lower continental crust to thesource of mantle-derived basaltic igneous rocks has beenrecognized in the genesis of the Plio-Pleistocene tholeiiticand alkaline volcanic rocks in Sardinia (Italy) (Lustrino

109W. Yang, S. Li / Lithos 102 (2008) 88–117

et al., 2000). In this case, the lavas have lowNb/U, Ce/Pb,and unradiogenic Pb isotopes. Consequently, the negativeNb anomaly, lowCe/Pb, and low 206Pb/204Pb of the Lanqibasalts may also suggest involvement of the lower crustmaterials in their formation process.

The Lanqi basalts have extremely low Ni and Crcontents and lower Th, U contents than the Yixian lavas,suggesting that the Lanqi basalts might have experi-enced significant olivine fractional crystallization fromprimary melts. Fig. 9 shows Ni–MgO relationships forpartial melting and fractional crystallization models(Hart and Davis, 1978). Ni content decreases signifi-cantly with olivine fractional crystallization. If primarymagmas have MgO contents of 12%, N20% olivinecrystallization of these primary melts could produce theresidual liquids with such low Ni (b16 ppm) and lowMgO (b3%) contents. However, olivine fractionalcrystallization alone will increase Th, U contents ofthe melt, which is not the case for the Lanqi basalts.Therefore, we propose that the basalts underwent AFCprocess at the crust–mantle boundary so that assimila-tion of plagioclase from the mafic granulites canproduce very low Th, U, Cr, and Ni, but high Al2O3

and CaO contents in the Lanqi basalts.

5.3.2. The Lanqi andesites and rhyolitesThe very low ɛNd(T) values and negative Sr and Eu

anomalies of the Lanqi andesites and rhyolites distin-

Fig. 9. Ni–MgO relationships for partial melting-fractional crystalli-zation models (after Hart and Davis, 1978). Model mantle peridotitecomposition and Ni partition coefficients are after Hart and Davis(1978). Partial melting curves are shown for batch partial melts of 5%and 20%. Fractional crystallization curves are shown for liquidsstarting on the 5% melting line with MgO contents of 8, 12, 16 and20%. Numbers at cross-tics are the amount of olivine crystallized.Solid squares represent the Lanqi basaltic samples. This diagramshows that the Lanqi basalts with low MgO and Ni contents could beproduced by 20% olivine fractional crystallization of a primary basalticmagma with MgO=12%.

guish them from the Xinglonggou and the Yixianandesites. Enrichment of LREE relative to HREE, highLILE/HFSE, positive Pb anomalies, low Ce/Pb ratios,and EM-I type isotopic compositions of the Lanqiandesites indicate a derivation from partial melting ofthe continental lower crust. In addition, the negative Srand Eu anomalies suggest plagioclase as a residual orcrystallizing phase. Thus, the Lanqi andesites could beformed by partial melting of the lower crust duringbasaltic magma underplating.

5.4. Origin of the Yixian lavas

5.4.1. The Yixian basaltsBasalts from the Yixian Formation are similar to the

Lanqi basalts in trace elements and isotopic composi-tions except for their higher Cr and Ni contents(Supplementary Tables 2 and 4 and Fig. 2). Enrichmentof LREE relative to HREE, high LILE/HFSE, positivePb anomalies, EMI-type isotopic compositions, and lowNb/U and Ce/Pb ratios strongly indicate the “continentallower crust” signatures for the basalts from the YixianFormation. Thus, the continental lower crust might alsoplay an important role in generating the Yixian lavas.Because the basalts from the Yixian Formation havehigher MgO, Cr, Ni, Th, U contents and lower Al2O3,CaO contents than those from the Lanqi Formation, themodel of magmatic underplating with AFC process isnot suitable for the Yixian basalts. The Yixian basaltscould be derived from a newly enriched lithospheremantle formed by ascending asthenosphere hybridizedby melt produced by partial melting of the founderingmafic lower continental crust (see below) (Lustrino,2005). In addition, relatively high ɛNd(T) values (0∼−2)for the basalts with K–Ar age of 133 Ma developed onthe bottom of the Yixian Formation in the Xinkailingvillage, Yixian county have been reported in theliterature (Ji et al., 2004; Shao et al., 2006) (seeFig. 11). These olivine basalts with high ɛNd(T) valuesmay suggest an earlier partial melting of the upwellingmantle before hybridization by partial melts from thefoundered mafic lower continental crust.

5.4.2. The Yixian high-Mg# adakitesThe Yixian high-Mg# adakites show similar geo-

chemical characteristics to the Xinglonggou high-Mg#adakites, such as SiO2%N56 wt.%, Al3O2%N15 wt.%,MgOb3 wt.%, Yb18 ppm, Ybb1.9 ppm, SrN400 ppm,no negative Eu anomaly, Mg#N54, CrN200 ppm,and NiN100 ppm. However, the Yixian adakites aredifferent from the Xinglonggou high-Mg# adakites inthe Sr–Nd–Pb isotopic compositions. The Yixian

110 W. Yang, S. Li / Lithos 102 (2008) 88–117

adakites have unradiogenic Pb (206Pb/207Pbb16.7,207Pb/204Pbb15.3, and 208Pb/204Pbb36.7), moderate87Sr/86Sri (∼0.706), and low ɛNd(T) (b−9.7). These Sr–Nd–Pb isotopic compositions and positive Ba anomalyrelative to Rb and Th are similar to those of the lowercontinental crust (Rudnick and Gao, 2003). Therefore,the Yixian high-Mg# adakites are more likely to bederived by partial melting of a foundered mafic lowercontinental crust instead of subducted oceanic crust.

In addition, although the Yixian lavas are evolved interms of major elements and compatible trace element,all the Yixian lavas can be divided into two groups asshown by the two negative correlations in the Nb/Ta–SiO2 diagram (Fig. 10): the basaltic series and theadakitic series. Therefore, it is unlikely that the Yixianadakites were produced via AFC processes involvingbasalt and magma mixing.

5.5. Origin of the Zhanglaogongtun basalts

The geochemical and isotopic compositions of theZhanglaogongtun basalts are similar to those of theCenozoic Kuandian and Hannuoba basalts (Zhou andArmstrong, 1982; Peng et al., 1986; Song et al., 1990;Basu et al., 1991; Liu et al., 1995a,b; Barry and Kent,1998) and Mesozoic Jianguo basalts (Zhang et al.,2003). Because Zhanglaogongtun basalts show low87Sr/86Sri (b0.704), high ɛNd(T) (N4), and radiogenicPb, sharing some common features of modern MORBand OIB, they are interpreted to derive from theasthenospheric mantle. However, the enriched LREEand LILE as well as the positive Nb and Ta anomaliessuggest that the upwelling asthenosphere must have

Fig. 10. Nb/Ta vs. SiO2 diagrams for the Yixian lavas showing twonegative correlation trends: basaltic series and andesite series,indicating two independent magma evolution trends. Data source: Jiet al. (2004), Wang et al. (2005) and this paper. Solid symbols and opensymbols represent data from this paper and from the literature,respectively.

been metasomatized by a SiO2-rich melt before the lateearly Cretaceous to reconcile the contradiction betweenthe depleted Nd isotopic and LREE enriched traceelement signatures. The relatively high Nb and Tacontents of the Zhanglaogongtun basalts suggest that theSiO2-rich melt for mantle metasomatism may beproduced by partial melting of the dehydrated subductedoceanic crust (Sajona et al., 1996).

Large scale E–W extension in Eastern Chinaoccurred during the period of the Zhanglaogongtunbasalt eruption (109∼94 Ma), responding to thesubduction of the western Pacific oceanic plate beneaththe eastern Asiatic continental margin (Zhao et al.,2004). Geochronologic studies indicate that the timingfor the strike-skip deformation of the Tan-Lu fault zonewas ca. 143∼114 Ma, and then the Tan-Lu faulttransferred into extension in the late early Cretaceousand the Tertiary (Zhu et al., 2001a,b, 2005). Theextensional activities resulted in development of a seriesof basins. The Fuxin Formation, discomformablyunderlying the Zhanglaogongtun Formation, is cut bythe fault-bounded depressions (Cheng et al., 1999). Thisobservation indicates that the Zhanglaogongtun basaltserupted during the large-scale extension. The extensioninduced upwelling and de-compressional partial meltingof asthenosphere. Lavas derived from the upwellingasthenosphere accordingly have the isotopic signaturesof depleted mantle.

The Nd isotope data and ages of the Mesozoic basaltsin western Liaoning are summarized in Fig. 11, showingthat the basalts with depleted Nd isotopic compositionserupted twice in Western Liaoning at about 133 Ma and109–94 Ma. This indicates two tectonic extensions andmantle upwelling events. The first upwelling of theasthenospheric mantle is of relatively short duration,which could be due to the foundering of the mafic lowercontinental crust, as indicated by the Yixian high-Mg#adakites. The second upwelling of the asthenosphericmantle is significant and related to the large scale E–Wextension mentioned above, which occurred earlier thanthat (75 Ma) in Shandong Province (Xu et al., 2004a andreferences therein). This observation indicates that the lateMesozoic extensional activities in Eastern China occurredearlier in the north than in the south, which is consistentwith the clockwise rotation of the Korea Peninsularelative to the Eurasia plate since Early Cretaceous (Zhuet al., 2002).

5.6. A lithospheric evolution model

The mechanism for the lithospheric thinning of theNCC is still controversial. There are tree representative

Fig. 11. Variation of ɛNd(T) with time of the mafic rocks from WesternLiaoning. Data source: Lanqi formation, this paper; Yixian, Ji et al.(2004), Shao et al. (2006), and this paper; Zhanglaogongtun formation,Zhang et al. (2003) and this paper.

111W. Yang, S. Li / Lithos 102 (2008) 88–117

models, i.e., the thermal mechanical and chemicalerosion model (Menzies and Xu, 1998; Xu, 2001; Xuet al., 2004a,b), the delamination model (Gao et al.,2004; Wu et al., 2005), and hydro-weakening of thesubcontinental lithospheric mantle due to subductiondehydration (Niu, 2005). The first model proposes thatthe lithosphere was gradually removed by thermal andchemical erosion from upwelling asthenosphere, whichis supported by their complied data showing continuousmagmatism in the eastern China during the Mesozoicfrom 180 to 90 Ma (e.g. Xu, 2001). However, this modelis not consistent with our new dating results showingfour Mesozoic magmatic episodes in the WesternLiaoning instead of a continuous magmatism from180 Ma to 90 Ma. The second model proposes that thelithospheric thinning resulted from foundering of themafic lower continental crust (together with theunderlying lithospheric mantle). This is supported bythe discovery of the Xu-Huai eclogite (Xu et al., 2002b),which suggests the existence of thickened continentalcrust of the NCC during the Mesozoic. It is generallysuggested that following the lithospheric delamination,de-compressional melting of the ascending astheno-spheric mantle will take place, creating basaltic melt withdepleted isotopic signature. Thus the geochemicalsignatures of the mantle-derived rocks should changeabruptly following delamination. Therefore, this modelwas inconsistent with foundering of the thickened lowercontinental crust at 159 Ma, as suggested by Gao et al.(2004), because the basalts with depleted isotopicsignatures in the NCC are not been observed until134 Ma (Shao et al., 2006). The third model suggestedthat hydro-weakening of the SCLM due to subductiondehydration may transfer the lithosphere mantle to

asthenosphere (Niu, 2005). Obviously, hydro-weaken-ing of the SCLM is very important for lithosphericthinning or destruction, however, weakening alone cannot explain theMesozoic high-Mg# adakites in the NCC.Perhaps the lithospheric thinning of the NCC is acomplex and multi-stage process and was not caused byany single event.

The reported age and geochemical data for theMesozoic volcanic rocks in the Western Liaoning arevery useful in understanding the lithospheric evolution.Based on the geochronological, geochemical data of theMesozoic volcanic rocks, we propose a geodynamicmodel for the lithospheric evolution of the North marginof the NCC.

5.6.1. Partial melting of the Palaeo-oceanic crustThe Palaeo-oceanic lithosphere subducted beneath

the northern margin of the NCC along the Solonkersuture at 300–250 Ma (Xiao et al., 2003). TheXinglonggou adakite is likely to be produced by partialmelting of this subducted oceanic crust. We suggest thatthe Palaeo-oceanic lithosphere was underplating be-neath the north margin of the NCC after subduction, andthen it was foundered in the Jurassic, which was causedby the collision between the NCC with the attachedsouthern Central Asian Orogen and the northern CentralAsian Orogen in the early middle Jurassic (Tomurtogooet al., 2005). The foundered oceanic crust was partiallymelted at 177 Ma.

5.6.2. Basaltic magma underplatingThe geochemical features of the Lanqi basalts

indicate a magma underplating event which causedpartial melting of the low-middle crust to produce thevoluminous low-Mg andesites and acidic volcanic rocksoverlying the Lanqi basalts. Foundering of the Palaeo-oceanic crust may trigger mantle upwelling and itspartial melting, which resulted in the magma under-plating event at ca. 166 Ma. Accordingly, the maficlower continental crust in the western Liaoning area wasthickened. The newly formed mafic lower crust hadtypical geochemical features of the lower continentalcrust of the NCC, which was overprinted by the AFCprocess as mentioned above.

5.6.3. Pre-135 Ma thrust tectonicsThe Pre-135 Ma thrust tectonics in the Yanshan belt

is marked by coarseclastic deposits of the Tuchengziformation (Davis et al., 2001; Zhao et al., 2004). Thisprocess may further thicken the crust, resulting ineclogitic facies transformation in the mafic lowercrust.

112 W. Yang, S. Li / Lithos 102 (2008) 88–117

5.6.4. Lower crustal founderingThe large-scale strike-skip of the Tan-Lu fault in the

early Cretaceous caused regional extension and thedestruction of the lithosphere underneath the northernmargin of the NCC. This triggered foundering of thethickened mafic lower continental crust. We emphasizethat this process was unlikely to have been caused byany single event. Both convective removal of themantle lithosphere from the bottom, and founderingof the mafic lower crust could have significantlythinned the lithosphere. Reaction of partial meltsfrom the foundered eclogitic lower continental crustwith mantle peridotite produced the Yixian high-Mg# adakites. Partial melting of the upwelling as-thenospheric mantle in response to foundering of lowercontinental crust produced the Yixian high ɛNd(T)basalts, and then the ascending asthenosphere hybrid-ized by partial melts from the foundered mafic lowercontinental crust formed a newly enriched lithosphericmantle which could be the source of the Yixian low ɛNd(T) basalts.

5.6.5. Large-scale extensionLarge-scale late Cretaceous extension in eastern

China, responding to the subduction of the westernPacific plate beneath the eastern Asiatic continentalmargin, resulted in further thinning of the lithosphere.The Zhanglaogongtun basaltic lavas were derived fromupwelling asthenosphere and accordingly show astheno-sphere isotopic signatures.

6. Conclusions

Integrated geochronologic, major and trace elementaland Sr–Nd–Pb isotope studies of the Mesozoic lavas inWestern Liaoning allow us to reach the followingconclusions:

(1) Geochronologic studies suggest that there were fourepisodes of Mesozoic volcanism in Western Liaon-ing, corresponding to the Xinglonggou Formation(ca. 177 Ma), the Lanqi Formation (166–148 Ma),the Yixian Formation (126–120 Ma), and theZhanglaogongtun Formation (∼ 106 Ma),respectively.

(2) The Xinglonggou high Mg andesites with typicalisland arc-type Sr–Nd–Pb isotopic features wereproduced by partial melting of the subductedoceanic crust at ca. 177 Ma.

(3) The basalts from the Lanqi Formation are high inAl2O3 and CaO, low in MgO, Ni, Cr, Th, and Ucontents, enriched in LREE, LILE, and Pb,

depleted in HFSE. They also have low Ce/Pb,Nb/U ratios, low ɛNd(t) (− 14∼− 9), high87Sr/86Sr (0.705∼0.707), and unradiogenic Pbisotopes. These features suggest the involvementof lower continental crustal materials in theirmagma source followed by olivine fractionalcrystallization. Thus, magmatic underplatingwith an AFC process at the crust–mantleboundary is a reasonable model for the originof the Lanqi lavas, which could provide the heatrequired for partial melting of the low-middlecrust to produce the voluminous andesites andrhyolites overlying above the basalts in the LanqiFormation.

(4) The Yixian high-Sr, low-Y andesites are high-Mg# adakitic rocks. Their Sr–Nd–Pb isotopecompositions show typical “lower continentalcrust” features. This suggests that the Yixianhigh-Mg# adakitic rocks are likely to be derivedfrom partial melting of foundered lower conti-nental crust, which resulted in the initial litho-sphere thinning in the early Cretaceous. TheYixian basalts and basaltic andesites show similargeochemical characteristics to the Lanqi basaltsexcept the lower Mg, Ni, and Cr contents of thelatter. The Yixian basalts could be derived from anewly enriched lithospheric mantle formed byascending asthenosphere hybridized by partialmelts from foundered lower mafic continentalcrust.

(5) The geochemical and isotopic compositions ofthe Zhanglaogongtun basalts are similar to thoseof the Cenozoic alkali basalts in Eastern China.They could be derived from the long-termdepleted mantle enriched by metasomatism ofSiO2-rich melt derived from subducted oceaniccrust of Western Pacific plate in the Cretaceous.This depleted mantle upwelling event occurred inresponse to large-scale late Cretaceous extensionin Eastern China and resulted in further thinningof the lithosphere.

Acknowledgements

This work was funded by the Natural ScienceFoundation of China (Grant. No. 40573010) andChinese Academy of Sciences (CX0767). We thankZ.W. Lu, J.G. Sha, S. Gao, J.A. Shao, H.F. Zhang for fieldsupport, and X.L. Tu, H. Qian, A.L. Zheng, Fei Wang,Fang Wang, P. Jian for technical assistance with ICP-MS,TIMS analyses and Ar–Ar, U–Pb dating. Discussionswith G.A. Davis were very helpful. This paper benefited

113W. Yang, S. Li / Lithos 102 (2008) 88–117

from comments and suggestions from Y.L. Niu, S. Gao,R.L. Rudnick, Y.L. Xiao, and F. Huang.

Appendix A. Supplementary data

Supplementary data associated with this articlecan be found, in the online version, at doi:10.1016/j.lithos.2007.09.018.

References

Barry, T.L., Kent, R.W., 1998. Cenozoic magmatism in Mongolia andthe origin of central and east Asian basalts. In: Flower, M.F.J.,Chung, S.L., Lo, C.H., Lee, T.Y. (Eds.), Mantle Dynamics andPlate Interactions in East Asia. American Geophysical Union,Geodynamics Series, vol. 27, pp. 347–364.

Basu, A.R., Wang, J.W., Huang, W.K., Xie, G.H., Tatsumoto, M.,1991. Major element, REE and Pb, Nd and Sr isotopicgeochemistry of Cenozoic volcanic rocks of eastern China:implications for origin from suboceanic-type mantle reservoirs.Earth and Planetary Science Letters 105, 149–169.

Brenan, J.M., Shaw, H.F., Ryerson, F.J., Phinney, D.L., 1995.Mineral-aqueous fluid partitioning of trace elements at 900 °Cand 2.0 GPa: constraints on the trace element chemistry of mantleand deep crustal fluids. Geochimica et Cosmochimica Acta 59,3331–3350.

Buchan, C., Pfänder, J., Kröner, A., Brewer, T.S., Tomurtogoo, O.,Tomurhuu, D., Cunningham, D., Windley, B.F., 2002. Timing ofaccretion and collisional deformation in the Central AsianOrogenic Belt: implications of granite geochronology in theBayankhongor ophiolite zone. Chemical Geology 192, 23–45.

Castillo, P.R., Janney, P.E., Solidum, R.U., 1999. Petrology andgeochemistry of Camiguin island, southern Philippines: insights tothe source of adakites and other lavas in a complex arc setting.Contributions to Mineralogy and Petrology 134, 33–51.

Chen, B., Zhai, M., 2003. Geochemistry of late Mesozoic lamprophyredykes from the Taihang Mountains, north China, and implicationsfor the sub-continental lithospheric mantle. Geological Magazine140, 87–93.

Chen, Y.X., Chen, W.J., Zhou, X.H., Li, Z.J., Liang, H.D., Li, Q., Xu,K., Fan, Q.C., Zhang, G.H., Wang, F., Wang, Y., Zhou, S.Q., Chen,S.H., Hu, B., Wang, Q.J., 1997. Liaoxi and Adjacent MesozoicVolcanic rocks: Chronology, Geochemistry and Tectonic Settings.The Seismological Press, Beijing. (in Chinese).

Chen, P.J., Dong, Z.M., Zhen, S.N., 1998. An exceptionally well-preserved theropod dinosaur from the Yixian Formation of China.Nature 391, 147–152.

Chen, W.J., Zhou, X.H., Li, Q., Yang, J.H., Li, D.M., Chen, S.H.,Zheng, D.W., Wan, J.Q., Zhang, G.H., Wang, F., 1999. Researchon Mesozoic volcanic chronology, geochemistry and tectonicsettings around the Liaohe River. Internal Report of the Institute ofGeology, Seismological Bureau of China. (in Chinese).

Chen, F., Hegner, E., Todt, W., 2000. Zircon ages, Nd isotopic andchemical compositions of orthogneisses from the Black Forest,Germany — evidence for a Cambrian magmatic arc. InternationalJournal of Earth Sciences 88, 791–802.

Chen, F., Siebel, W., Satir, M., Terzioglu, N., Saka, K., 2002.Geochronology of the Karadere basement (NW Turkey) andimplications for the geological evolution of the Istanbul zone.International Journal of Earth Sciences 91, 469–481.

Chen, B., Jahn, B.M., Zhai, M., 2003. Sr–Nd isotopic characteristicsof the Mesozoic magmatism in the Taihang–Yanshan orogen,North China Craton, and implication for Archaean lithospherethinning. Journal of the Geological Society (London) 160,963–970.

Chen, W., Ji, Q., Liu, D.Y., Zhang, Y., Song, B., Liu, X.Y., 2004.Isotope geochronology of the fossil-bearing beds in the Daohugouarea, Ningcheng, Inner Mongolia. Geological Bulletin of China 23,1165–1169. (in Chinese).

Cheng, R.H., Cao, S.L., Wang, D.P., Liao, X.M., 1999. The basementstructures and tectonic patterns of the Mesozoic basins in WesternLiaoning Province and its northern adjacent area. Journal ofChangchun University of Science and Technology 29, 29–32.(in Chinese).

Chung, S.L., Liu, D.Y., Ji, J.Q., Chu, M.F., Lee, H.Y., Wen, D.J., Lo,C.H., Lee, T.Y., Qian, Q., Zhang, Q., 2003. Adakites fromcontinental collision zones: melting of thickened lower crustbeneath southern Tibet. Geology 31, 1021–1024.

Davis, G.A., 2005. The Late Jurassic “Tuchengzi/Hongcheng”formation of the Yanshan fold thrust belt: an analysis. EarthScience Frontiers 12, 331–345.

Davis, G.A., Zheng, Y.D., Wang, C., Darby, B.J., Zhang, C.H., Gehrels,G., 2001. Mesozoic tectonic evolution of the Yanshan fold and thrustbelt, with emphasis on Hebei and Liaoning provinces, northernChina. In: Hendrix, H.S., Davis, G.A. (Eds.), Paleozoic andMesozoic Tectonic Evolution of Central Asia: From ContinentalAssembly to Intracontinental Deformation. Boulder Colorado,Geological Society of America Memoir, vol. 194, pp. 171–197.

Defant, M.J., Drummond, M.S., 1990. Derivation of some modern arcmagmas by melting of young subducted lithosphere. Nature 347,662–665.

Defant, M.J., Xu, J.F., Kepezhinskas, P., Wang, Q., Zhang, Q., Xiao,L., 2002. Adakites: some variations on a theme. Acta PetrologicaSinica 18 (2), 129–142.

Deng, J.F., Mo, X.X., Zhao, H.L., Luo, Z.H., Du, Y.S., 1994.Lithosphere root/de-rooting and activation of the east China.Modern Geology 8, 349–356. (in Chinese).

Deng, J.F., Zhao, H.L.,Mo,X.X.,Wu, Z.X., Luo, Z.H., 1996. ContinentalRoots-Plume Tectonics of China — Key to the ContinentalDynamics. Geological Publishing House, Beijing. (In Chinese).

Deng, J.F., Mo, X.X., Zhao, H.L., Wu, Z.X., Luo, Z.H., Su, S.G.,2004. A new model for the dynamic evolution of Chineselithosphere: “continental roots-plume tectonics”. Earth ScienceReviews 65, 223–275.

Fan, W.M., Menzies, M.A., 1992. Destruction of aged lowerlithosphere and accretion of asthenosphere mantle beneath easternChina. Geotectonica et Metallogenia 16, 171–180.

Fan, W.M., Zhang, H.F., Baker, J., Jarvis, K.E., Mason, P.R.D.,Menzies, M.A., 2000. On-craton and off-craton Cenozoic spinelperidotites in eastern China: similarity and difference. Journal ofPetrology 41, 933–950.

Fan, W.M., Guo, F., Wang, Y.-J., Lin, G., Zhang, M., 2001. Post-orogenic bimodal volcanism along the Sulu orogenic belt in easternChina. Physics and Chemistry of the Earth (A) 26, 733–746.

Fraser, K.J., Hawkesworth, C.J., Erland, A.J., Mitchell, R.H., Scott-Smith, B.H., 1985. Sr, Nd and Pb isotope and minor elementgeochemistry of lamproites and kimberlites. Earth and PlanetaryScience Letters 76, 57–70.

Gao, S., Rudnick, R.L., Carlson, R.W., McDonough, W.F., Liu, Y.S.,2002. Re–Os evidence for replacement of ancient mantlelithosphere beneath the North China craton. Earth and PlanetaryScience Letters 198 (3–4), 307–322.

114 W. Yang, S. Li / Lithos 102 (2008) 88–117

Gao, S., Rudnick, R.L., Yuan, H.L., Liu, X.M., Liu, Y.S., Xu,W.L., Ling,W.L., Ayers, J., Wang, X.C., Wang, Q.H., 2004. Recycling lowercontinental crust in the North China craton. Nature 432, 892–897.

Griffin, W.L., O'Reilly, S.Y., Ryan, C.J., 1992. Composition andthermal structure of the lithosphere beneath South Africa, Siberiaand China: proton microprobe studies. On Cenozoic VolcanicRocks and Deep-seated Xenoliths in China and its Environments.Abstracts of International Symposium on Cenozoic VolcanicRocks and Deep-seated Xenoliths in China and its Environments,Beijing, pp. 65–66.

Griffin, W.L., Zhang, A.D., O'Reilly, S.Y., Ryan, C.G., 1998.Phanerozoic evolution of the lithosphere beneath the Sino–Koreancraton. In: Flower, M.F.J., Chung, S.L., Lo, C.H., Lee, T.Y. (Eds.),Mantle Dynamics and Plate Interactions in East Asia. AmericanGeophysical Union, Geodynamics Series, vol. 27, pp. 107–126.

Guo, F., Fan, W.M., Wang, Y.J., Lin, G., 2001. Late Mesozoic maficintrusive complexes in North China Block: constraints on theNature of subcontinental lithospheric mantle. Physics andChemistry of the Earth (A) 26, 759–771.

Guo, F., Fan, W.M., Wang, Y.J., Lin, G., 2003. Geochemistry of laterMesozoic mafic magmatism in west Shandong Province, easternChina: characterizing the lost lithospheric mantle beneath theNorth China Block. Geochemical Journal 37, 63–77.

Guo, F., Nakamuru, E., Fan, W., Kobayoshi, K., Li, C., 2007.Generation of Palaeocene adakitic andesites by magma mixing;Yanji Area, NE China. Journal of Petrology 48, 661–692.

Hart, S.R., 1984. A large-scale isotope anomaly in the southernhemisphere mantle. Nature 309, 753–757.

Hart, S.R., Davis, K.E., 1978. Nickel partitioning between olivine andsilicate melt. Earth and Planetary Science Letters 40, 203–219.

He, H.Y., Wang, X.L., Zhou, Z.H., Zhu, R.X., Jin, F., Wang, F., Ding,X., Bowen, A., 2004. 40Ar/39Ar dating of ignimbrite from InnerMongolia, northeastern China, indicates a post-Middle Jurassic agefor the overlying Daohugou Bed. Geophysical Research Letters31, L20609. doi:10.1029/2004GL020792.

Hofmann, A.W., 1997. Mantle geochemistry: the message fromoceanic volcanism. Nature 385, 219–229.

Hou, L.H., 1996. A carnate bird from the upper Jurassic of westernLiaoning, China. Chinese Science Bulletin 41, 1861–1864. (inChinese).

Hou, L.H., Zhou, Z.H., Martin, L.D., Feduccia, A., 1995. A beakedbird from the Jurassic of China. Nature 337, 616–619.

Huang, X.L., Xu, Y.G., Liu, D.Y., 2004. Geochronology, petrologyand geochemistry of the granulite xenoliths from Nushan, eastChina: implication for a heterogeneous lower crust beneath theSino–Korean Craton. Geochimica et Cosmochimica Acta 68,127–149.

Huang, F., Li, S.G., Dong, F., Li, Q.L., Chen, F., Wang, Y., Yang, W.,2007a. Recycling of deeply subducted continental crust in theDabie Mountains, central China. Lithos 96, 151–169.

Huang, F., Li, S.G., Yang, W., 2007b. Contributions of the lower crustto Mesozoic mantle-derived mafic rocks from the North ChinaCraton: implications for lithospheric thinning. In: Zhai, M.G.,Windley, B.F., Kusky, T.M., Meng, Q.R. (Eds.), Mesozoic Sub-Continental Lithospheric Thinning Under Eastern Asia. GeologicalSociety Special Publication, vol. 280, pp. 55–75.

Jahn, B.M., 1990. Origin of granulites: geochemical constrains fromArchaean granulite facies rocks of the Sino–Korean craton, China.In: Vielzeuf, D., Vidal, Ph. (Eds.), Granulites and Crustal Evolution.Khrwer Academic Publishers, Netherlands, pp. 471–492.

Jahn, B.M., Auvray, B., Cornichet, J., Bai, Y.L., Shen, Q.H., Liu, D.Y.,1987. 3.5 Ga-old amphibolites from eastern Hebei province,

China: field occurrence, petrography, Sm–Nd isochron age andREE geochemistry. Precambrian Research 34, 311–346.

Jahn, B.M., Wu, F., Lo, C.H., Tsai, C.H., 1999. Crust–mantleinteraction induced by deep subduction of the continental crust:geochemical and Sr–Nd isotopic evidence from post-collisionalmafic–ultramafic intrusions of the northern Dabie complex.Chemical Geology 157, 119–146.

Ji, Q., Currie, P.J., Norell, M.A., Ji, S.A., 1998. Two feathereddinosaurs from northeastern China. Nature 393, 753–761.

Ji, Q., Chen, W., Wang, W.L., Ji, X.C., Zhang, J.P., Liu, Y.Q., Zhang,H., Yao, P.Y., Ji, S.A., Yuan, C.X., Zhang, Y., You, H.L., 2004.Mesozoic Jehol Biota of western Liaoning, China. Geologicalpublishing house, Beijing.

Kay, R.W., Kay, S.M., 1993. Delamination and delaminationmagmatism. Tectonophysics 219, 177–189.

Keppler, H., 1996. Constraints from partitioning experiments on thecomposition of subduction zone fluids. Nature 380, 237–240.

Kogiso, T., Tatsumi, Y., Nakano, S., 1997. Trace element transportduring dehydration processes in the subducted oceanic crust:1. Experiments and implications for the origin of ocean islandbasalts. Earth and Planetary Science Letters 148, 193–205.

Le Maitre, R.W., Bateman, P., Dubek, A., Keller, J., Lameyre, J.,Le Bas, M.J., Sabine, P.A., Schimid, R., Sorensen, H., 1989.A Classification of Igneous Rocks and Glossary of Terms:Recommendations of the International Union of Geological SciencesSubcommission the Systematics of Igneous Rocks. Blackwell,Oxford.

Li,W.P., 2006. Geochemical characteristics of the early Jurassic dacitesof the Xinglonggou Formation in Beipiao area, western Liaoningprovince. Acta Petrologica Sinica 22 (6), 1608–1616. (in Chinese).

Li, S.G., Yang, W., 2003. Decoupling of surface and subsurfacesutures in the Dabie orogen and a continent-collisional lithospher-ic-wedging model: Sr–Nd–Pb isotopic evidences of Mesozoicigneous rocks in eastern China. Chinese Science Bulletin 48,831–838.

Li, S.G., Xiao, Y., Liou, D., Chen, Y., Ge, N., Zhang, Z., Sun, S.S.,Cong, B., Zhang, R., Hart, S.R., Wang, S., 1993. Collision of theNorth China and Yangtze Blocks and formation of coesite-bearingeclogites: timing and processes. Chemical Geology 109, 89–111.

Li, S.G., Nie, Y.H., Hart, S.R., Zhang, Z.Q., 1998. Interaction betweensubducted continental crust and the mantle — II. Sr–Nd isotopicgeochemistry of post-collisional mafic–ultramafic rocks from theDabie mountains. Science in China (D) 41, 632–638.

Li, W.P., Li, X.H., Lu, F.X., 2001. Genesis and geological significancefor the middle Jurassic high Sr and low Y type volcanic rocks inFuxin area of west Liaoning, northeastern China. Acta PetrologicaSinica 17, 523–532. (in Chinese).

Li, W.P., Li, X.-H., Lu, F.-X., Zhou, Y.-Q., Zhang, D.-G., 2002.Geological characteristics and its setting for volcanic rocks of earlyCretaceous Yixian Formation in western Liaoning province,eastern China. Acta Petrologica Sinica 18, 193–204. (in Chinese).

Li, X.Y., Fan, W.M., Guo, F., Wang, Y.J., Li, C.W., 2004. Modificationof the lithospheric mantle beneath the northern North China Blockby the Palaeoasian Ocean: geochemical evidence from the maficvolcanic rocks of the Nandaling Formation in the Xishan area,Beijing. Acta Petrologica Sinica 20, 557–566. (in Chinese).

Liu, D.Y., Nutman, A.P., Compston, W., Wu, J.S., Shen, Q.H., 1992.Remnants of 3800 crust in the Chinese Part of the Sino–Koreancraton. Geology 20, 339–342.

Liu, C.Q., Masuda, A., Xie, G.H., 1994. Major- and trace-elementcompositions of Cenozoic basalts in eastern China: petrologenesisand mantle source. Chemical Geology 114, 19–42.

115W. Yang, S. Li / Lithos 102 (2008) 88–117

Liu, C.Q., Xie, G.H., Masuda, A., 1995a. Geochemistry of Cenozoicbasalts from eastern China—I. Major element and trace elementcompositions: petrogenesis and characteristics of mantle source.Geochemistry 24, 1–19. (in Chinese).

Liu, C.Q., Xie, G.H., Masuda, A., 1995b. Geochemistry of Cenozoicbasalts from eastern China—II. Sr, Nd and Ce isotopic composi-tions. Geochemistry 24, 203–213. (in Chinese).

Liu, Y., Liu, H., Li, X., 1996. Simultaneous and precise determinationof 40 trace elements in rock samples using ICP-MS. Geochimica25, 552–558. (in Chinese).

Liu, Y., Hu, R., Zhao, J., Feng, C., 2004a. Petrogenesis and sourcecharacteristics of the late Cretaceous mafic dike from the Luxi area:petrology and geochemistry. Geological Review 50, 577–586.(in Chinese).

Liu, Y.Q., Liu, Y.X., Li, P.X., Zhang, H., Zhang, L.J., Li, Y., Xia, H.D.,2004b. Daohugou biota-bearing lithostratigraphic succession on thesoutheastern margin of the Ningcheng basin, Inner Mongolia, and itsgeochronology. Geological Bulletin of China 23, 1180–1185. (inChinese).

LNGMR (Liaoning Bureau of Geology and Mineral Resources), 1989.Regional Geology of Liaoning Province. Geological PublishingHouse, Beijing. (in Chinese).

Ludwig, K.R., 2001. Isoplot/Ex, rev. 2.49: a geochronological toolkitfor Microsoft Excel. Berkeley Geochronological Center, SpecialPublication, vol. 1a, p. 58.

Lugmair, G.W., Marti, K., 1978. Lunar initial 143Nd/144Nd:differential evolution of the lunar crust and mantle. Earth andPlanetary Science letters 39, 349–357.

Lustrino, M., 2005. How the delamination and detachment of lower crustcan influence basalticmagmatism. Earth ScienceReviews 72, 21–38.

Lustrino, M., Melluso, L., Morra, V., 2000. The role of lowercontinental crust and lithospheric mantle in the genesis of Plio-Pleistocene volcanic rocks from Sardinia (Italy). Earth andPlanetary Science Letters 180, 259–270.

Ma, X.Y., 1987. Lithospheric dynamics map of China and adjacentseas (1:4000000) and explanatory notes. Geological PublishingHouse, Beijing. (in Chinese).

Ma, J.L., Xu, Y.G., 2006. Sm–Nd isotopic features of the mantle-derived xenolith from Yangyuan in the Hebei Province indicatingEM-I type ancient enriched mantle in the North China Craton.Chinese Science Bulletin 51 (10), 1190–1196. (in Chinese).

Martin, H., 1999. Adakitic magmas: modern analogues of Archaeangranitoids. Lithos 46, 411–429.

Martin, H., Smithies, R.H., Rapp, R., Moyen, J.F., Champion, D.,2005. An overview of adakite, tonalite–trondhjemite–granodiorite(TTG), and sanukitoid: relationships and some implications forcrustal evolution. Lithos 79, 1–24.

Manning, C.E., 2004. The chemistry of subduction-zone fluids. Earthand Planetary Science Letters 224, 1–16.

Meng, Q.R., Zhang, G.W., 2000. Geologic framework and tectonicevolution of the Qinling orogen, central China. Tectonophysics323, 183–196.

Menzies, M.A., Xu, Y.G., 1998. Geodynamics of the North Chinacraton. In: Flower, M.F.J., Chung, S.L., Lo, C.H., Lee, T.Y. (Eds.),Mantle Dynamics and Plate Interactions in East Asia. AmericanGeophysical Union, Geodynamics Series, vol. 27, pp. 155–165.

Menzies, M.A., Fan, W.M., Zhang, M., 1993. Palaeozoic andCenozoic lithoprobe and the loss of N120 km of Archaeanlithosphere, Sino–Korean craton, China. In: Prichard, H.M.,Alabaster, T., Harris, N.B.W., Neary, C.R. (Eds.), MagmaticProcesses and Plate Tectonics. Geological Society specialpublication, pp. 71–81.

Niu, Y., 2005. Generation and evolution of basaltic magmas: somebasic concepts and a new view on the origin of Mesozoic–Cenozoic basaltic volcanism in eastern China. Geological Journalof China Universities 11, 9–46.

Peate, D.W., Kokfelt, T.F., Hawkesworth, C.J., Calsteren, P.W.V.,Hergt, J.M., Pearce, J.A., 2001. U-series isotope data on LauBasin glasses: the role of subduction-related fluids duringmelt generation in back-arc basins. Journal of Petrology 42,1449–1470.

Peng, Z.C., Zartman, R.E., Futa, E., Chen, D.G., 1986. Pb-, Sr- andNd-isotopic systematics and chemical characteristics of Cenozoicbasalts, eastern China. Chemical Geology 59, 3–33.

Qiou, J.S., Wang, D.D., Zeng, J.H., 1997. Trace element and Sr–Ndisotopic geochemistry of the K-rich volcanic rocks and lamproitefrom Luxi area. Geological Journal of China University 3,384–395. (in Chinese).

Qiou, J.S., Xu, X.S., Lo, C.-H., 2002. Potash-rich volcanic rocks andlamprophyres in western Shandong Province: 40Ar–39Ar datingand source tracing form Luxi area. Chinese Science Bulletin 47,91–99.

Rapp, R.P., Watson, E.B., 1995. Dehydration melting of metabasalt at8–32 kbar: implications for continental growth and crust–mantlerecycling. Journal of Petrology 36 (4), 891–931.

Rapp, R.P., Shimizu, N., Norman, M.D., Applegate, G.S., 1999. Reactionbetween slab-derived melts and peridotite in the mantle wedge:experimental constraints at 3.8GPa. Chemical Geology 160, 335–356.

Rapp, R.P., Laporte, D., Martin, H., 2005. Adakite inducedmetasomatism of the mantle wedge: a systematic experimentalstudy at 1.6 GPa. American Geophysical Union, Fall Meeting2005, abstract #V31C-0628.

Ren, D., Gao, K.Q., Guo, Z.G., Ji, S., Tan, J.J., Song, Z., 2002.Stratigraphic division of the Jurassic in the Daohugou area,Ningcheng, Inner Mongolia. Geological Bulletin of China 21,584–591. (in Chinese).

Robinson, P.T., Zhou,M.F., Hu, X.F., Reynolds, P., Bai, W.J., Yang, J.S.,1999. Geochemical constraints on the origin of the Hegenshanophiolite, Inner Mongolia, China. Journal of Asian Earth Sciences17, 423–442.

Rollinson, H., 1993. Using geochemical Data: Evaluation, presenta-tion, interpretation. Longman, London, p. 352.

Rudnick, R.L., Fountain, D.M., 1995. Nature and composition of thecontinental crust: a lower crustal perspective. Review of Geophysics33, 267–309.

Rudnick, R.L., Gao, S., 2003. Composition of the continental crust. In:Rudnick, R.L. (Ed.), The Crust. Volume 3 of Treatise onGeochemistry. Elsevier-Pergamon, Oxford, pp. 1–64.

Rudnick, R.L., Gao, S., Ling,W.L., Liu, Y.S.,McDonough,W.F., 2004.Petrology and geochemistry of spinel peridotite xenoliths fromHannuoba and Qixia, North China craton. Lithos 77, 609–637.

Sajona, F.G., Maury, R.C., Bellon, H., Cotton, J., Defant, M., 1996.High field strength element enrichment of Pliocene–PleistoceneIsland Arc Basalts, Zamboanga Peninsula, Western Mindanao(Philippines). Journal of Petrology 37, 693–726.

Sengör, A.M.C., Natal'in, B.A., Burtman, V.S., 1999. Evolution of thealtaid tectonic collage and Palaeozoic crustal growth in Eurasia.Nature 364, 299–307.

Shao, J.A., Li, X.H., Zhang, L.Q., Mao, B.L., Liu, Y.L., 2001.Geochemical condition for genetic mechanism of the Mesozoicbimodal dyke swarms in Nankou Guyaju. Geochimica 31, 517–524.(in Chinese).

Shao, J.A., Chen, F.K., Lu, F.X., Zhou, X.H., 2006. Mesozoicpulsative upwelling diapirs of asthenosphere in west Liaoning

116 W. Yang, S. Li / Lithos 102 (2008) 88–117

province. Journal of China University of Geosciences 31, 807–816.(in Chinese).

Shen, Y.B., Chen, P.J., Huang, D.Y., 2003. Age of fossil conchos-tracans from Daohugou of Ningcheng, Inner Mongolia. Journal ofStratigraphy 27, 311–313. (in Chinese).

Song, Y., Frey, F.A., Zhi, X.C., 1990. Isotopic characteristics ofHannuoba basalts, eastern China: implications for their petrogen-esis and the composition of subcontinental mantle. ChemicalGeology 85, 35–52.

Song, B., Zhang, Y.H., Liu, D.Y., 2002. Introduction to the Naissanceof SHRIMP and its contribution to isotope geology. Journal ofChinese Mass Spectrometry Society 23, 58–62. (in Chinese).

Steiger, R.H., Jager, E., 1977. Subcommission on geochronology:convention on the use of decay constants in geochronologyand cosmochronology. Earth and Planetary Science Letters 36,359–362.

Suhr,G., Sech,H.A., Shimizu, Z., Gunther,D., Jenner,G., 1998. Infiltrationof refractory melts into the lowermost oceanic crust evidence fromdunite- and gabbro-hosted clinopyroxenes in the Bay of islandsophiolite. Contributions to Mineralogy and Petrology 131, 136–154.

Sun, S.S., McDonough, W.F., 1989. Chemical and isotopicsystematics of oceanic basalts: implication for mantle compo-sition and processes. In: Saunders, A.D., Norry, M.J. (Eds.),Magmatism in the Ocean Basins. Geological society, London,pp. 313–345.

Swisher, C.C., Wang, Y.Q., Wang, X.L., Xu, X., Wang, Y., 1999.Cretaceous age for the feathered dinosaurs of Liaoning, China.Nature 400, 58–61.

Swisher, C.C., Wang, X.L., Zhou, Z.H., Wang, Y.Q., Jin, F., Zhang, J.Y.,Xu,Q., Zhang, F.Y.,Wang,Y., 2001. Further support for a Cretaceousage for the feathered-dinosaur beds of Liaoning, China: new40Ar/39Ar dating of the Yixian and Tuchengzi Formations. ChineseScience Bulletin 47, 135–138.

Tomurtogoo, O., Windley, B.F., Kroner, A., Bandarch, G., Liu, D.Y.,2005. Zircon age and occurrence of the Adaatsag ophiolite andMuron shear zone, central Mongolia: constraints on the evolutionof the Mongol–Okhatsk ocean, suture and orogen. Journal of theGeological Society (London) 162, 125–134.

Wang, W.L., Zheng, S.L., Zhang, L.J., Pu, R.G., Zhang, W., Wu, H.Z.,Ju, R.H., Dong, G.Y., Yuan, H., 1989. Mesozoic Stratigraphy andPaleontology of Western Liaoning (1), vol. 168. GeologicalPublishing House, Beijing. (in Chinese).

Wang, S.S., Hu, H.G., Li, P.X., Wang, Y.Q., 2001a. Further discussionon the geologic age of Sihetun vertebrate assemblage in westernLiaoning, China: evidence from Ar–Ar dating. Acta PetrologicaSinica 17, 663–668. (in Chinese).

Wang, S.S., Wang, Y.Q., Hu, H.G., Li, H.M., 2001b. The existingtime of Sihetun vertebrate in western Liaoning, China — evi-dence from U–Pb dating of zircon. Chinese Science Bulletin 46,779–782.

Wang, X.R., Gao, S., Liu, X.M., Yuan, H.L., Hu, Z.C., Zhang, H.,Wang, X.C., 2005. Geochemistry of high-Mg andesites from theearly Cretaceous Yixian Formation in Sihetun, Western Liaoning:indication on lower crustal dalamination and Sr/Y variation.Science in China (D) 35, 700–709. (in Chinese).

Wang, Q., Wyman, D.A., Xu, J., Jian, P., Zhao, Z., Li, C., Xu,W.,Ma, J.,He, B., 2007. Early Cretaceous adakitic granites in the NorthernDabie complex, central China: implications for partial melting anddelamination of thickened lower crust. Geochimica et CosmochimicaActa 71, 2609–2636.

White, W.M., 2005. Geochemistry, p. 339. An on-line text book, http://www.geo.cornell.edu/geology/classes/geo455/Chapters.HTML.

Williams, I.S., Claesson, S., 1987. Isotope evidence for thePrecambrian provenance and Caledonian metamorphism of highgrade paragneisses from the Seve Nappes, Scandinavian Caledo-nides, 2 ion microprobe zircon U–Th–Pb. Contributions toMineralogy and Petrology 97, 205–217.

Wu, F.Y., Walker, R.J., Ren, X.W., Sun, D.Y., Zhou, X.H., 2003.Osmium isotopic constraints on the age of lithospheric mantlebeneath northeastern China. Chemical Geology 196, 107–129.

Wu, F.Y., Lin, J.Q., Wilde, S.A., Zhang, X.O., Yang, J.-H., 2005.Nature and significance of the Early Cretaceous giant igneousevent in eastern China. Earth and Planetary Science Letters 233,103–119.

Xiao, W.J., Windley, B.F., Hao, J., Zhai, M.G., 2003. Accretionleading to collision and the Permian Solonker Suture, InnerMongolia, China: termination of the central Asian orogenic belt.Tectonics 22 (6), 1069. doi:10.1029/2002TC001484.

Xu, Y.G., 2001. Thermo-tectonic destruction of the Archaeanlithospheric keel beneath the Sino–Korean craton in China:evidence, timing and mechanism. Physics and Chemistry of theEarth (A) 26, 747–757.

Xu, J.F., Shinjo, R., Defant, M.J., Wang, Q., Rapp, R.P., 2002a. Originof Mesozoic adakitic intrusive rocks in the Ningzhen area of eastChina: partial melting of delaminated lower continental crust?Geology 289, 1912–1916.

Xu, W.L., Wang, D.Y., Liu, X.C., Wang, Q.H., Lin, J.Q., 2002b.Discovery of eclogite inclusions and its geological significance inearly Jurassic intrusive complex in Xuzhou, northern Anhui,eastern China. Chinese Science Bulletin 47, 1212–1216.

Xu, Y., Huang, X., Ma, J., Wang, Y., Iizuka, Y., Xu, J., Wang, Q., Wu,X., 2004a. Crust–mantle interaction during the tectono-thermalreactivation of the North China Craton: constraints from SHRIMPzircon U–Pb chronology and geochemistry of Mesozoic plutonsfrom western Shandong. Contributions to Mineralogy andPetrology 147, 750–767.

Xu, Y.,Ma, J., Huang,X., Izuka, Y., Chung, S.,Wang, Y.,Wu,X., 2004b.EarlyCretaceous gabbroic complex fromYinan, Shandong Province:petrogenesis and mantle domains beneath the North China Craton.International Journal of Earth Sciences 93, 1025–1041.

Xu, W.L., Wang, Q.H., Wang, D.Y., Guo, J.H., Pei, F.P., 2006.Mesozoic adakitic rocks from the Xuzhou–Suzhou area, easternChina: evidence for partial melting of delaminated lowercontinental crust. Journal of Asian Earth Sciences 27, 454–464.

Xu, H., Ma, C., Ye, K., 2007. Early cretaceous granitoids and theirimplications for the collapse of the Dabie orogen, eastern China:SHRIMP zircon U–Pb dating and geochemistry. Chemical Geology240, 238–259.

Yang, J.H., Chung, S.L., Zhai, M.G., Zhou, X.H., 2004. Geochemicaland Sr–Nd–Pb isotopic compositions of mafic dikes from theJiaodong Peninsula, China: evidence for vein-plus-peridotitemelting in the lithospheric mantle. Lithos 73, 145–160.

Yang, W., Li, S.G., Jiang, B.Y., 2007. New evidence for Cretaceousage of the feathered dinosaurs of Liaoning: zircon U–Pb SHRIMPdating of the Yixian Formation in Sihetun, north-east China.Cretaceous Research 28, 177–182.

Zhang, H.F., 2005. Transformation of lithospheric mantle throughperidotite-melt reaction: a case of Sino–Korean craton. Earth andPlanetary Science Letters 237, 768–780.

Zhang, H.F., Sun, M., 2002. Geochemistry of Mesozoic basalts andmafic dikes, Southeastern North China craton, and tectonicimplications. International Geological Review 44, 370–382.

Zhang, H., Zhang, Q., 2005. Rare earth, trace element characteristicsof high-Mg volcanic rocks of Yixian formation in Sihetun, West

117W. Yang, S. Li / Lithos 102 (2008) 88–117

Liaoning province and its apocalypse. Journal of the Chinese RareEarth Society 23, 736–741. (in Chinese).

Zhang, H.F., Sun, M., Zhou, X.H., Fan, W.M., Zhai, M.G., Yin, J.F.,2002. Mesozoic lithosphere destruction beneath the North ChinaCraton: evidence from major-, trace-element and Sr–Nd–Pbisotope studies of Fangcheng basalts. Contributions to Mineralogyand Petrology 144, 241–253.

Zhang, H.F., Sun, M., Zhou, X., Zhou, M., Fan, W., Zheng, J., 2003.Secular evolution of the lithosphere beneath the eastern NorthChina Craton: evidence from Mesozoic basalts and high-Mgandesites. Geochimica et Cosmochimica Acta 67, 4373–4387.

Zhang, H.F., Sun, M., Zhou, M., Fan, W., Zhou, X., Zhai, M., 2004.Highly heterogeneous Late Mesozoic lithospheric mantle beneaththe North China craton: evidence from Sr–Nd–Pb isotopicsystematics of mafic igneous rocks. Geological Magazine 141,55–62.

Zhang, H., Liu, X.M., Li, Z.T., Yang, F.L., Wang, X.R., 2005a. EarlyCretaceous large-scale crustal thinning in the Fuxin–Yixian basinand adjacent area in Western Liaoning. Geological Review 51,360–372. (in Chinese).

Zhang, H.F., Sun, M., Zhou, X.H., Ying, J.F., 2005b. Geochemicalconstraints on the origin of Mesozoic alkaline intrusive complexesfrom the North China Craton and tectonic implications. Lithos 81,297–317.

Zhao, Y., Zhang, S.H., Xu, G., Yang, Z.Y., Hu, J.M., 2004. TheJurassic major tectonic events of the Yanshanian intraplatedeformation belt. Geological Bulletin of China 23, 854–863. (inChinese).

Zheng, J.P., Lu, F.X., 1999. Mantle xenoliths from kimberlites,Shandong and Liaoning: paleozoic mantle character and itsheterogeneity. Acta Petrologica Sinica 15, 65–74. (in Chinese).

Zheng, J.P., O'Reilly, S.Y., Griffin, W.L., Lu, F.X., Zhang, M.,Pearson, N.J., 2001. Relict refractory mantle beneath the easternNorth China block: significance for lithosphere evolution. Lithos57, 43–66.

Zheng, J.P., Sun, M., Lu, F.X., Pearson, N., 2003. Mesozoic lowercrustal xenoliths and their significance in lithospheric evolutionbeneath the Sino–Korean Craton. Tectonophysics 361, 37–60.

Zhou, X.H., Armstrong, R.L., 1982. Cenozoic volcanic rocks ofeastern China — secular and geographic trends in chemistry andstrontium isotopic composition. Earth and Planetary ScienceLetters 59, 301–329.

Zhou, Z.H., Barrett, P.M., Hilton, J., 2003. An exceptionally preservedLower Cretaceous ecosystem. Nature 421, 807–814.

Zhu, G., Song, C.Z., Wang, D.X., Liu, G.S., Xu, J.W., 2001a. Studieson 40Ar/39Ar thermochronology of strike-slip time of the Tan-Lufault zone and their tectonic implications. Science in China (D) 44,1002–1009.

Zhu, G., Wang, D.X., Liu, G.S., Song, C.Z., Xu, J.W., Niu, M.L.,2001b. Extensional activities along the Tan-Lu fault zone and itsgeodynamic setting. Chinese Journal of Geology 36, 269–278. (inChinese).

Zhu, R.X., Shao, J.A., Pan, Y.X., Shi, R.P., Shi, G.H., Li, D.M., 2002.Paleomagnetic data from Early Cretaceous volcanic rocks ofwestern Liaoning: evidence for intracontinental rotation. ChineseScience Bulletin 47, 1832–1837.

Zhu, G., Niu, M.L., Liu, G.S., Wang, Y.S., Xie, C.L., Li, C.C., 2005.40Ar/39Ar dating for the strike-slip movement on the Feidong partof the Tan-Lu fault belt. Acta Geologica Sinica 79, 303–316. (inChinese).

Zindler, A., Hart, S., 1986. Chemical geodynamics. Annual Review ofEarth Planetary Sciences 14, 493–571.