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2ndThe Int’l Symposium of International Geoscience Programme IGCP Project 608
Tectono-magmatic Development of Accreted West Burma Blockfrom
Naing Maw Than (MGSS)
Gondwana Land6th Sept, 2014, Wasewda
1Photo courtesy by Dr. Win Swe (2012)
The Second International Symposium ofInternational Geoscience Programme (IGCP) Project 608"Cretaceous Ecosystems and Their Responses to
Western Pacific"Paleoenvironmental Changes in Asia and the
I_UG_S
_ ...._..,._
EDU-"
·"
-.
2
± Naing Maw Than, he received B.Sc. (Hons), M.Sc.Univ. of Mandalay and Dip. in Computer Science ofand M.Sc. (Petroleum Geoscience), Univ. of Brunei,
(Geology) fromI.C.S.T (Yangon)life member of
MGS (Myanmar Geosciences Society), AAPG and executive member ofMGSS (Myanmar Geologists Society, Singapore).He presently works as I/M manager Cum
basingeologist in SK E&C
(Singapore) and main interests in study and reservoircharacterization.
_,.,I
Eastelock
Fig.1 ' I
Sunde Prati orSundaland' Block
/
Bay ofBengal
lndanOoean
4
INTRODUCTION Two Hypothesis
It seems probable that the WMB and the Sibumasu were formerly independent blocks or slivers which rift at different times off a supercontinent known as the Gondwanaland in the southern hemisphere (Ridd, 1971, Stauffer, 1974), and drifted northward across different generations of Tethys Oceans, and collided and amalgamated with Asia, and also with each other (Metcalfe, 1997).
The present available data supported the above tectonic scenariofor the Sibumasu Block, more convincingly than for the earlyhistory of the WMB which needs more research work to verify.
5
6
Fore –Arc Sliver Model (Mac Caffrey,2009)
The Sibumasu Block probably rift off the NW Australia which was attached to therigid Antarctica to the south, both forming parts of the Gondwanasupercontinent until Carboniferous, and drifted northward in late Early Permian.
It collided and sutured in Late Triassic with the Indochina Block (IndosinianOrogeny), also of the Gondwana origin, to form the Sunda Block or Plate,covering much of the mainland of Southeast Asia and its offshore continentalshelves and also the southern margin of Asia (Figure 2 & 3).
7Hall et al. 2010 IPA
Fig.2
Sibumasu
Fig.3
) Collision
of Subumasu
Block
with
Indochina Block
r,
- Indochina
Song Gp
Hua/ Hin Lat Fms
- Fig. Cartoon sections across
Indochina
I Sibumasu
or
Indochina block in the Late..,I_
Sukholhai Arr; ..._
Accretionary
& granite
---• Oceanic crust
.. plate-tectonic setting. NUS: Nnn•-
8
Sibumasu
PALAEOTETHYS CLOSED BACK-ARC
Earliest Triassic ~--'--1 BASIN
Mae Slllfang Fm
Fanr; Chell
~Gp
MESOTETHYS
!Late Triassic!INTHANON ZONE Nam Pa/Gp
Nam Phong&
MESOTETHYS
Nonhern and NE Thailand to show the narrowing of the Palaeotethys ocean in the earliest Triassic and the final collision of the Sibumasu block with the Sukhothai Arc/
'----' Shan-Thai Terrane Terrane ._ ..,! Indochina Terrane Triassic (modified from
Sonc &
Metcalfe 2008}. Triassic lirhostratigraphic units have beenAcid volcanic rocks added to show their interpretedcomplex (S & I types) Utturndit Suture.
The south Asian margin remained passive until Jurassic when itbecame an active margin with repeated magmatic andmetamorphic episodes, the latest thermal event occurring in lateMiocene.
WMB extending into West Sumatran block carrying an intra-oceanic magmatic island arc with continental basement alsofollowed suit from the other part from the northern margin ofAustralia probably in Late Triassic to Early Jurassic, and frontalmagmatic arc collided with the Sunda Block (Sibumasu part) inMid-Cretaceous,
while much farther south of their present position (Mitchell et al.,2007), leading to the formation of high-grade metamorphicMogok Belt along the collision zone and generating both I-typeand S-type granites in the belt. Subduction shifted to the westmargin of the WMB .
9
Fig.4)
Myanmar
at the
junction
of four
tectonic
plates (After Win Swe. 2012)EHS
1. Eurasian Plate2. Indian Plate3. SE Asia/Sunda Plate4. Burma Plate
Major Structures in the region
1. MBT= Main boundary Thrust2. EHS= East Himalayan Syntaxis3. Sunda Mega thrust4. Sagaing Fault5. Andaman Spreading
(After Win Swe 2012)
10
WEST MYANMAR BLOCK OR BURMA PLATE Composed of CMB, WR and RCB
CMB is probably a continental fragment overlain by Triassic –Recent clastic strataintruded by a volcano-plutonic arc (Mid-K-R) along its medial axis, forming an intra-oceanic magmatic island arc.Collided with Sibumasu block in mid-K creating high-to medium-grade metamorphicbelt and emplacement of both I-type & S-type granitoids along the suture zone,Mogok Belt.
Further subducted by the oceanic lithosphere from the west; Up K- Eocene., flysch ofaccretionary wedge (WR) and coeval sequence of Western Outcrops depositedrespectively in a trench and fore arc trough of the magmatic arc along the medial axisof CMB.
In Oligocene the accretionary wedge was uplifted in the W, dextral shear basins andSagaing Fault were formed in the E due to hyper-oblique subduction by theIndian/Australian Plate and subsequent indentation in Himalayan Arc followingcollision in the Himalayan Arc.
Dextral slip SF transects mostly along the old suture zone, and Andaman Basinopened in Miocene, offsetting Burma Plate northward for ~333 km and pushing WSumatra farther southwards 11
Fig.5) FOUR MAJOR PHYSIO-TECTONIC BELTS OF MYANMAR
1. Eastern HighlandsProvince(EHP),Central Myanmar Belt (CMB)Western Ranges (WR),Rakhine Coastal Belt (RCB).
2.3.4.
WEST MYANMAR BLOCK ORBURMA PLATE Composed ofCMB (Triassic-Q) Wt.Metamorphic Basement ,WR (Up K- Plio)RCB (Eocene-Plio) andCVL Central Volcanic Line
12
Three Continental Blocks : East Malaya_Sibumasu_West Sumatara (Barber & Crow, 2009)
Southeast Asia is made up of a series of continental blockswhich separated from northern Gondwana during the LatePaleozoic and Mesozoic and were subsequently accreted to thesouthern margin of Asia with the subduction of the interveningoceanic crust.
From east to west the Malay peninsula and Sumatra arecomposed of three continental blocks: East Malaya, Sibumasuand West Sumatra (Barber and Crow , 2009).
13
A Hypothesis of West Sumatara and West Burma Detachement outbord of Subamu in TR
Hutchison (1994) and Barber et al.(2003) proposed a hypothesis,during the Triassic an elongated slice, including West Sumatra andWest Burma, became detached from Cathaysia (Indochina) along amajor transcurrent fault and was translated along the westernmargin ofterrane.
SE Asia to its present position outboard of the Sibumasu
14
Fig.6) Continental tectonic blocks in Southeast Asia (after Metcalfe 2005).
The contact between theSibumasu block and theWest Sumatra block ismarked by the MedialSumatra Tectonic Zone(MSTZ), a distance of 1760km and interpreted as amajor transcurrent fault.
Barber and Crow (2005)correlated the MSTZ withthe Mogok Belt ofMyanmar and the WestBurma block is theextension of the WestSumatra block, from whichit was separated by theformation of the AndamanSea in the Miocene(Curray, 2005).
15
,94°EFig
~ -\
I
I
C
- ,,,. ,-,
' \
I
PLATEAU
I
I '
,_-' THAILII
' ' '' '-
16°
0
Shan Thai(Sibumasu) BlockD
290'' ' Late Cretaceous
Granites','
-Mogok Meta•morphic Belt = MSTZ
'
--
HINA
West Burma Block= West Sumatra Block Jurassic to Early K and were
24 Mawgyi Nappe= Woyla Nappe
Ophiolites
'
-
Mount Victoria metamorphics
-Cenozoic AccretionaComplexes
'} Deformation Front
AND
1 i
Strike-Slip Fault
QuaternaryVolcanoes
16°
16
Metcalfe (1996, 2005) suggested that the Sikuleh microcontinental terrane, incorporated in the Woyla terranes and the West Burma block, separated in the Late
accreted in the mid K.
The Woyla nappe is interpreted as an intraoceanic arc thrust over the West
rySumatra block and the WoylaArc was certainly accreted toSE Asia as part of the Woylanappe in the mid K.(Barber 2000; Barber & Crow2008).
.7
Fig.8) Outline Map of Mawgyi Nappe in Western SE Asia (After Mitchell, 1993)
East-ward vergingMawgyi nappe of maficarc rocks and ophiolite inMyanmar andequivalents in Sumatra,Borneo and Tibet in Mid-K.
Myanmar west ofSagaing Fault restored toMid-K position.(After A. Mitchell, 1993)
17
Fig.9)
Latest
Arrival
of Indian
Platform
to Eurasia at Eocene (After Win Swe. 2012)
The latest arrival of a majorblock of Gondwana origin inour part of Asia is the Indianplatform or subcontinentwhich left the parentGondwanaland in EarlyCretaceous, collided andsutured in Eocene with theEurasian Plate,an assembly of suturedblocks, leading to theformation of the greatHimalayan Mountain Rangeand the high TibetanPlateau.
18
GIAC Project (1999-2002)
Fig.10)
Myanmar
at the
junction
of four
tectonic plates (After Win Swe.
2012)
1.2.3.4.
Sunda PlateBurma PlateIndia PlateEurasian Plate
Major Structures in the region
1. MBT= Main boundary2. EHS= East HimalayanSyntaxis3. Sunda Megathrust4.Sagaing Fault5. Andaman Spreading
Thrust
(After Win Swe 2012)
19
Fig.11)
Present
Day
Tectonic
Setting
of Myanmar
(Win
Swe,
2012)
20
Present Day Tectonic Setting of Myanmar (Win Swe, 2012)
During northward indentation of India into Asia the region eastand southeast of Tibet underwent large scale right-lateral shearand clockwise rotation, the right-lateral Sagaing fault in Burmawhich marks the eastern margin of the NNE moving Indian plateduring the Neogene.
The consequences of this collision (Himalayan Orogeny) andcontinuing convergence between the two blocks are, amongothers, propagation of major lateral shears, in part probably byreactivating the pre-existing structures, to the east and southeast,translating continental blocks out of the collision zone androtation of the Sunda block or plate clockwise (Tapponner et al.,1986,2008), the processes commonly known as "Extrusion orEscape Tectonism”. (After Win Swe, 2012)
21
g.12) CoIr)• llision in the Himalayan Arc (Tapponier et al, 2008) 105'
110 •
TAR J .UNOIITN
8 AST V
CHINA
oRoo•
35'
22
Fi
Regional DEM of Asia with outlines of key basins,Escape Tectonismand structural features
Molnar and Tapponnier model 23
CVL (Central Volcanic Line) in Myanmac / Tettono Magmatic Development
Igneous rocks ranging in age from Lower Jurassic to Pleistocene or earlyRecent occur sporadically in a1500 km long ‘volcanic arc’ throughout the Central Lowlands (Chhibber1934). The arc coincides with an axis within the Central Lowlandssedimentary basin (Central Burma Basin), dividing it into Western andEastern Troughs that represents arc volcanism above an east-dippingsubduction zone . The Central Volcanic Line (CVL) arc is terminated by Southat Andaman sea spreading center which has been active since Mid-Miocene(Curray, 1979).
Mitchell (1981), Stephenson and Marshall (1984) stated that prior to theinitiation of the Andaman Sea spreading centers the volcanic arc wascontinuous southwards with the Sumatra and Sunda arcs of Indonesia(Hutchison 1982), in which many high-K calc-alkaline volcanic centers havegeochemical and mineralogical similarities to the Burma volcanics (Whitford1975; Whitford & Nicholls 1976; Leo et al. 1980).This is particularly true in northern Sumatra where fault controlled Miocene toRecent volcanoes, with remarkable similarity to those of comparable age inBurma, are developed on the southwestern continental margin of the
Sundaland Craton (Rock & Syah 1983) (See in Stephenson and Marshall, 1984).24
Fig.13) Geological
Map
of Myanmar
(MGS,
2014)
Mitchell et al. (2012)speculated that, inCretaceous the Wuntho–Popa arc (United Nations1978c) was much furthersouth, within the westernpart of the presentAndaman Sea andpossibly Sumatra–Wuntho–Popa–Mokpalin arccontinued northwardsthrough diorite andgranodiorite intrusionswithin the TagaungMyitkyina Belt (TMB) ofBurma.
Kaw Lin-Wuntho
Popa
25
Mokpalin
Fig.14)Generalized Geological cross-section of Myanmar
,along Lat. 21˚
N
26
Southern Chin Hills MinbuBasin Chauk ML Popa Meiktila-Thazi PindayaPlain Range
GENERALLIZED GEOLOGICAL CROSS-SECTION MYANMAR,APPROXIMATELY ALONG LATITUDE 2 r NORTH
(Vertical scale greatly exaggerated)
I - Chaung Magyi Group; 2 - Lower Paleozoic units; 3 - Lower Carboniferous units;
4 - Plateau Limestone; 5 - Jurassic units; 6 - Mesozoic granitoids; 7 - Upper Cretaceous Paleocene ultrabasic rocks;
8 - Mesozoic-Eocene flysch; 9 - Eocene molasse; 10 - Pegu Group; l I - Irrawaddy sandsones; 12 - Upper Cenozoic volcanics; 13- Alluvium
Dr. U Thein, 2000
• 6 L9',t·C.,.- .. -- (t •
c:, '-"-• Fig.15
45
622•
7
8
THAILAND
....
1• tt,•
2
3
N
Lahar Deposits
Basalt, Basaltic Andesite & Pyroclastic ofComposite ConesBasalt & Lava Plateau
Dacite and/or Rhyolitic Pumice Flow
Rhyodacite ? Lava Domes
Andesitic Flows
Silicified/ Argilized Lava
Kyoukpodoung
~--··- ·-··--·--·- ...
N
Younger Volcanics
Older Volcanics
·
LJ lffowodd1on HO•tntntJ -Plioctnt
E!!J Peguon Mdrl're' -nts
·Miocene
• PlugO Cr(lflf
+ * Ao!;clone ond
>yn<I"'<Torrood
~Flow
·
f
Schematic section Vertical exoggeratioo i 2
27
Fig.1 A) 1.Narcodam, 2. Myaung Mya; 2, Narcodam Island, 3.Barren Island, 4. Mt.Loime & Jade Mine area, 5. Taungthonlon Volcano, 6. Lower Chindwin Cones, 7.Sone Taung Flows, 8.Mt.Popa, 9. Pegu Yoma Hills, 10. Tigyaing Flow, 11. Kabaw Flows, 12. Yezin,13.Thaton, 14. Medaw Island, Tectonic Features of Andman Sea from Curray et al. (1979)
Fig.16) Location ofet. al. 2004)
Samples on the Mt. Popa
Area Geological Map (After Stephenson et. al. 1984) (Mauay
1: sedimentary substratum of the volcano(Miocene to Lower Pleistocene);2: dacitic and/or rhyolitic pumice flows;3: andesitic flows;4: dacitic domes and flows;5: basaltic and basaltic andesitic flows;6: basaltic and andesitic basaltic pyroclasticdeposits from Mt. Popa cone;7: Popa (Taunggala) neck.
28Older Volcanics
Irrawaddy Fm.Pegu Group
Younger Volcanics
29
Fig.17) Satellite Image of Mt.Popa and Taungni Area
Mt.Popa
Dangyin
Taungni
Mongan
Microscopic Study of the Popa_Taungni Area
a
Fig. 18A) Mongan Andesite : the penetrated
twin plagioclase altered to sericitesubparallel with mcrophenocrysts of plagioclase (a) showing flow
directionFig. 18B) A phenocryst of hornblende (b) was replaced
and etched
around
itsboundarywit
hPerlitic
crck
(c) as
contraction
of cooling
stage
Fig. 19A) Orthopyroxene (d) was replaced by clinopyroxeneform the rim, while the inner core is fresh indicates the slow
(e) and magnetite torate of crystallizationFig .19B) Zoning and Twinning in auguite phenocryst with ophitic
texture andmicro phenocrysts of plagioclase in fine-grained groundmass
30
d
e
c
b
XRF
data of
Taungni Volcanic
Rocks
Plot
in Alkali
Vs.Silica
Diagrams
2
Fig.20 A & B ) XRF data of the Taungni volcanic
rocks
are plotted
in the alkali Vs. silicadiagram and K2O Vs. Silica diagrams indicate that most of samples are in the
alkaline andhigh K-calc alkaline fields.
Although such high - K Calc alkaline suite are known from island arcs, they are moreprevalent on continental margin where they are often associated with extremely K rich shoshonitic rocks.
31
K2 O
(W
t %
)
Alkaline
Sub Alkaline
4
Shoshonitic
3
High –K Alkaline
1
Calc Alkaline
Low_K
040 45 50 55 60 65 70
Si O2 (Wt %)
32
Volcanic
Rocks
Plot
for Mt.Popa
and other
environs
Singu,
Monywa,
Narcodam,
Barren Islands
Fig.21A) Plot of the studied
lavas in the classification diagrams Na2O + K2Ovs. SiO2 [Le Bas et
al., 1986] and K2O-SiO2 [Peccerillo and Taylor, 1976].
Fig. 21B )Filled circles: Mt. Popa basalts; empty circles: Mt.Popa basaltic andesites; empty
crosses: Mt. Popa andesites; empty diamonds: Mt. Popa dacites;
empty squares: Singu lavas; empty triangles: Monywa lavas;
empty inverted triangles: Tengchong lavas.(Maury et. al. 2004)
33
Genesis of Magma
Although such high - K Calc alkaline suite are known from islandarcs, they are more prevalent on continental margin where they areoften associated with extremely K rich shoshonitic rocks. A generalincrease in K2 O in lavas (for any given Si O2 contents) is usual withincreasing depth of magma generation along a subduction zone.
Most XRF data of the volcanic rocks in the Taungni area are plottedin the field of Potassium-rich Calc-alkaline suite which is attributedto the waning stage of orogeny as the obliquely eastwardsubduction of the Indian Plate beneath the Eurasian Plate that gaveway to strike-slip movement associated with the Andaman Seaspreading-centre.
34
Genesis of Magma
Within this tectonic model, the generation of potassic magma involved the partial
melting of phlogopite-bearing garnet peridotite at relatively deep levels in the
upper mantle (120 Km+), below the amphibole stability (Gupta & Yagi, 1980)
and the more siliceous lavas may have been derived by fractional crystallization
of such magmas at crustal levels (See in Stephenson and Marshall, 1984).
Stephenson & Marshall (1984) cited the observed spatial
continental margin is that in which sub-solidous aqueous
the dehydration of subducted oceanic crust, rise through
enriched mantle, scavenging incompatible elements.
variation beneath
solutions, released by
the overlying, possibly
The overall amount of enrichment would be in proportionate to the thickness of
overlying mantle and steepening of the subduction zone.
35
Genesis of Magma
The volume relationship tend to support a fractional crystallization for the origin of more
silicic rocks. The basalt and basaltic andesite of the Mt.Popa (Younger Volcanics) are
volumetrically far more abundant than andesite and silicified tuff (Older Volcanics) of the
Taungni area.The overall trend towards more primitive composition with volcanic time which is contrary
to other areas of calc-alkaline volcanicity. During the earlier stage, the
magma may have risen to the surface fairly, slowly allowing time for
fractional crystallization of plagioclase and Mg-bearing mafic phase to modify
the magma to older volcanic composition.Later activity, which followed a period of deformation, consisted almost entirely of
relatively undifferentiated Basalts and basaltic Andesite (Younger Volcanics).
These magma exploited newer-formed weakness and risen to the surface
rapidly, not allowing time for fractonation.
36
Fig.22) The three dimensional geometry of the Burma Wadati Benioff Zone (WBZ) , James. F. Ni. et al.(1989)
It was based upon the 184 hypocenters fromInternational Seismological Center (ICS).
The dip of the
inclined
Burma WBZ(subduction
IndianPlate) varies from about
the north near the east50 Southeast
inHimalayan syntaxis
to about 30
Northeast inthe bay of Bangal
area .the
extrapolated
trend surface
160
Kmcontour would pass through the volcanic arc inmap view.
Mt.Popa
The Main Large –Scale Tectonic features of The Myanmar_Thailand Area Cross~18° N. (Searle & Morley,2011)
Fig. 23)
Cross-section across southern Myanmar and northern Thailand illustrating some of themain large-scale tectonic features of the area. The surface geology used is taken
from ~18° N.(Searle & Morley, 2011). CVL was probably generated at the depth 180 Km..
37
Fig.24)
The Characteristics of the Burma Seismic Zone (Stroke et. al., 2008)
Current findings of
Stroke (2008) and
Searle & Morley
(2011) also
supported the
magma generation
depth range
(160-
180)
Km.
west-vergent fold-
FB
38
CMBFault
Himalaya Jade Mine Katha-
Belt GangawRange
Shilong PlateauPop-up Structure
Mogok Belt
Indo-Burma Ranges
Mt.Popa
thrust belt
Sagaing DI
Shan-Thai Block
Relation of Sedimentation, Volcanism and Tectonic Occurrences in Popa-Taungni Area
Pivnik et.al (1998) proposed :(1) Miocene extensional deformation of the20°N uplift and in the southeastern part of the Salin subbasin and the formation of grabens;(2) late Miocene uplift of the eastern side of the basin due to emplacement of the Mount Popa volcanics along basement-involved faults;(3) late Miocene–Pleistocene motion of the basin-center thrust sheets and formation ofthe Salin synclinorium (including uplift of the western outcrops); and(4) Pleistocene inversion of previously existing normal faults to form the southeastern uplifts and the 20°N uplift.
39
Relation of Sedimentation, Volcanism and Tectonic Occurrences in Taungni Area
From the Polyphase deformation of the Salin basin by Pivnik et.al (1998), firstly the Taungni area(the Older Volcanics) related with late Miocene uplift of the eastern side of the basin alongbasement-involved faults , secondly Pleistocene inversion of previously existing normal faults to form the southeastern uplifts and the 20°N uplift that related to Popa area (The Younger Volcanics).It could be extracted that the intraformational Irrawaddy unconformity in Gwegyo area alsosuggesting that transpression related uplift occurred after or during deposition of the upperIrrawaddy Formation, (Pleistocene), coeval with the basin-center thrust sheets.
40
Fig. 16) The Older Volcanics of Taungni Silicified Tuff and Dangyin Trachy Andesite intefingerring and overlying withIrrawaddy Fm. (Stephenson et. al. 1983).
Fig. 17) Schematic inversion of Gwegyo Thrust, unconformbly overlying Irrawaddy Fm. date the Pliocene_Pleistocene time.
Irrawaddy Fm.Altered Argillized & Silicified Rocks
Kyauktaga Volcanics
Trachyandesites
Irrawaddy Fm.
Depth-to-magnetic basement map of Central Myanmar Popa-Taungni area (Pivnik & et. al. 1998)
This inversion occurred in the Popa region as
resultant of Subduction co-exist with lateral strike-
slip fault forming the compressional and
transpressional deformation in Central Myanmar
basins.
The Mount Popa volcanics are interpreted to coincide
with basement fractures or faults; thus uplift in the
region also may be related to basement-involved41
Fig.15) Tomographic Patterns indicate E-NE trending uplifts possibly related to the Mount Popa volcanic trend, whichalso may be related to the normal faults (Pivnik, & et. al1998).
Regional uplift related to intrusion and extrusion of the Mount Popa volcanics appears to have tilted the footwall of the Gwegyo thrust
Fig. 16) Schematic inversion of Gwegyo Thrust, unconformbly overlying Irrawaddy Fm. date the Pliocene_Pleistocene time.
Mt.Popa
42
Genesis of Magma, Depth of Magma Generation
Morrison (1980) suggested that steepening of subduction plate can occur beneath a
thickening crust towards the end of an orogenic phase and prior to a flip (overturning) of
the zone or a change to strike-slip movement such as has recently occurred in Myanmar.It can be concluded that the magma generation of the Popa-Taungni area indicate a depth
range of (120-160 ) Km at relatively deeper part of the upper mantle related with
compressional and/or transpressional movement.Current findings of Stroke (2008) and Searle & Morley (2011) also supported the magma
generation depth range (160-180) Km.
Maury & et. al (2004) proposed The dehydration of this slab led to metasomatism and
subsequent melting of the Central Myanmar mantle wedge, and finally to the emplacement
of calc-alkaline and shoshonitic magmas in those volcanoes.These evidences provide a most useful local tectono-magmatic analogy and supportive for
West Burma block is the extension of the West Sumatra block.
Conclusion
1) Continental blocks of SE Asia separated from northern Gondwanaduring the Late PZ and MZ and were subsequently accreted to thesouthern margin of Asia with the subduction of the interveningoceanic crust.
2) From east to west the Malay peninsula and Sumatra are composed ofthree continental blocks: East Malaya, Sibumasu and West Sumatra.
3) Myanmar exits at the junction of four plates : Sunda PlateBurma Plate, India Plate and Eurasian Plate.
4) Myanmar is composed of two paleo-micro-continental blocks: Eastand West Blocks, both believed to be of Gowndana origin in MidCretaceous).
5) West Burma Block (Burma Plate) can be correlated withSumatra by Magamatism and intraoceanic arc thrust.
West
6) For correlation of Woyla Nappe and Mawgyi Nappe is needed moreresearch works to do.
Magmatic Activity Vs. Tectonic Stress, Time of Volcanism
Times of volcanism were drawn by the reviewing on Polyphase deformation of the Salin
basin (Pivnik et.al,1998) and stratigraphic evidences, firstly the Taungni area (The Older
Volcanic) related with late Miocene uplift of the eastern side of the Salin basin along
basement-involved faults.
Secondly, late Miocene–Pleistocene motion of the basin-center thrust sheets and formation
of the Salin synclinorium that probably related to Popa area (The Younger Volcanic)
supported by the age determination on samples of Mt. Popa’s area which indicate the early
Pleistocene age (0.80 to 0.96 m.a.) (Maury et. al. 2004).
44
Acknowledgement
• I tender my sincere thanks to Dr. Win Swe (Past President ofMGS
(Myanmar
Geoscience
Society)
who
drawn
acomprehensive
picture
of Myanmar1970.
Tectonic
Map
and
firstlynamed the Sagaing
Fault in
• Extended warmly
thanks
to those
referred chance
in context
andorganize
rsof IBCP60
8who
gave
a to meet
shadyWaseda
Campus.
REFERENCES :
1)Barber A. J. 2000. The origin of the Woyla Terranes in Sumatra and the Late Mesozoicevolution of the Sundaland margin. Journal of Asian Earth Sciences 18, 713–38.2) Barber A. J. & CROW M. J. 2003. Evaluation of plate tectonic models for the developmentof Sumatra. Gondwana Research 20, 1–28.3) Barber A. J., CROW M. J. & MILSOM J. S. (eds) 2005. Sumatra: Geology, Resources andTectonics. Geological Society Memoir 31. Geological Society of London, London.4) Barber A. J. & CROW M. J. 2009. Structure of Sumatra and its implications for the tectonicassembly of Southeast Asia and the destruction of Paleotethys : 2 Island Arc (2009) 18, 3–205)Chibber, H.L., 1934, The Geology of Burma : New Jersy, Prentice-Hall, Inc6)Curay J.R., Moore D.G., Lawver L.A., Emmel F.J., Raitt R.W., Henry M. & Kieckhfer R. (1979).– Tectonics of the Andaman Sea and Burma. In: T.S. Watkins, L. Martadet & P.W. Dickerson,Eds, Geological and geophysical investigations of continental margins. AAPG Mem., 29, 189-198.7) Curray, J.R. 2005. Tectonics and history of the Andaman Sea region. Journal of Asian EarthSciences, 25, 187-232.8) Gerven.M.van. and Pichler.H., 1995, Some aspects of volcanology and geochemistry ofthe Tengger Caldera, Java, Indonesia : Eruption of a K-rick tholeitic series, Jour. SE AsianEarth Sci. V.1, No.2, P.125-1339) Gupta, A.K and Yagi,K., 1980, Minerals and rocks . V.14; Petrology and genesis of lucite –bearing rocks. Sprimger- Verlag, Newyork
45
10) Hutchison, C.S., 1989. Geological Evolution of Southeast Asia. Oxford University Press.11) Khin Maung Tun, 1993, Petrology of the Shin Ma Taung Area, Pakkoku Tsp., Univ. ofMandalay, unpub. Master’s thesis12) Maung Maung, Aung Naing Thu, Suzuki, H., 2008. Latest Jurassic radiolarian faunafrom the Chyinghkran area, Myitkyina Township, Kachin State (Region),13) Maury. R.C., et. al., 2004, Quaternary calc-alkaline and alkaline volcanism in an hyper-oblique convergence setting, central Myanmar and western Yunnan (Bull. Soc. géol. Fr.,2004, t. 175, no 5, pp. 461-472)14) Metacalfe I. 1996. Pre-Cretaceous evolution of SE Asian terranes. In Hall R. & BlundellD. J. (eds).Tectonic Evolution of Southeast Asia. Geological Society, London, SpecialPublication 106, 97–122,Geological Society of London, London.15) Metacalfe I. 2005. Asia: South-East. In Selley R. C., Cocks L. R. M. & Plimer I. R. (eds).Encyclopedia of Geology, pp. 169–96. Elsevier, Amsterdam.16) Mitchell, A.H.G., 1981. Phanerozoic plate boundaries in mainland SE Asia, theHimalayas and Tibet. Journal of the Geological Society, London 138, 109–122.17) Mitchell, A.G.H. 1989. The Shan Plateau and WesternBurma: Mesozoic-Cenozoic plateboundaries and correlation with Tibet. In: Sengör, A.m.C. (ed.)Tectonic Evolution of theTethyan Region. KluwerAcademic Publishers, 567-583.18) Morrison, G.W. 1980, Charcteristics and tectonic setting of the shoshonite rockassociation : Lithos, 13, P. 101-12.19) Naing Maw Than, 1993, Petrology of the Taungni-Pingadaw Area, Kyaukpadaung Tsp.,Univ. of Mandalay, unpub. Master’s thesis
46
20) Naing Maw Than, 2012, Nature of the Central Volcanic Line in Taung Ni area, CentralMyanmar (Presented at AOGS 1012, Asia Oceania Geoscience Society, August 2012,Singapore)21) Ni, James F. Marco, Gunzman Speziale et al.,1989, Accreationary tectonics of Burmaand the three dimensional geometry of the Burma subduction zone: Geology, No.17, P.68-71.22) Marshall.T.R, Amos.B.J. & Stephenson.D, 1983, Base Metals Concentrations inSilicified and Argilized lavas of the The central Burma Volcanics (Geological Society,London, Special Publications 1983, V 11, P.59-68.)23) Oo,TIN H. & NYUNY H. 2002. Permian of Myanmar.Journal of Asian Earth Science 20,683–9.24) Stephenson, D. and Marshall.T.R. , 1984, The petrology and mineralogy of Mt. Popavolcano and the nature of the late Cenozoic Burma volcanic arc; Jour Geology. SocietyLondon, V.141, P.747-762.25) United Nations, 1978c. Geology and Exploration Geochemistry of the Salingyi-Shinmataung area, Central Burma. Technical Report No. 5, DP/UN/BUR-72-002/14,Geological Survey and Exploration Project, United Nations Development Programme.United Nations, New York, p. 29.26) Win Swe (2012) The Tectonic Evolution Of Myanmar: A Brief Overview, GEOSEA 2012(Bangkok, Thailand)27) Ye Min, 1992, Petrology of the Banmauk-Pinlebu Area, Kawlin-Wuntho Tsp., Univ. ofMandalay, unpub. Master’s thesis
47
Back Up
48
A) SOUTH SOUTH
CHINA CHINA
INDIA
INDIAv Transhimalayan arc
· ·· Yarlung Tsangpa-lrrawaddy·
1....~~......;;;;;;..~~~~~~~M.;.;.;.;;id~d~le~E~o~c~e~ne.;;..;;;c.~4~0~M~a;;..i~M~id~d~le;.:.;.M~io~.c.~..e~~-n-~-e'~Fig. 5. Paleogeographic reconstruction. A. Schematic reconstruction of rivers and suture zonesfor Late Eocene time (c. 40 Ma). Note the major rivers, including the Tsangpo–Irrawaddysystem, run parallel to the orogen. The continuous Transhimalayan arc includes the Gangdesebatholith, eastern Transhimalayan batholiths and the Mogok Metamorphic Belt and SlateBelt of Myanmar. B. During Early Miocene time (c. 20 Ma), the Tsangpo–Irrawaddy river keepspace with deformation around the syntaxis. C. By the Middle Miocene (c. 15 Ma), theYarlung Tsangpo–Irrawaddy river has disconnected, and the Yarlung Tsangpo has been capturedby the Lohit River (a tributary of the modern Brahmaputra). Namche Barwe is onlyshown to locate position of the syntaxis. Tectonic reconstructions and position of theWest
49Burma block relative to the Lhasa terrane and SE Asia are based on Hall (2002) and Metcalfe
90° 110°
China
ust Maler strike-slip fault
zones~ 20°: SMS
•.. •
•:
:NUS
7 :
. : LS•••••
Tersang, located along the Bentong-Raub Suture
Zone (RBS)
500 km
Regional Setting
IndiaMai
spreading centre
and Sewell Rises
Attenuated continental cr ene oceanic crust
Pliocene-Holocene oceanic crust 0 1 = Gaoligong Shear zone
2 = Chongshan Shear zone3 = Ailao Shan-Red
River hear zone4 = Sagaing Fault zone
s = Mae Ping Fault zone6 = Three Pagodas Fault zone7 = Ranong Fault zone8 = Khlong Marui Fault zone9 = West Andaman Fault zone10 = Sumatra Fault zone
·•
SSukhothai Zone
lnthanon Zone
Region underlain by accretedc oceanic crust, western ntains Woyla Terranes and
Mawgi NappeTerranes derived from Gondwana in the late Early Permian
••: Suture zones
MSS = Myitkyina Suture 10° ASS= Ailao Shan SutureMES= Menglian SutureSMS = Song Ma Suture CMS= Chiang Mai Suture NUS= Nan-Uttaradit Suture MS= Mae Sariang SutureLS = Loei SutureSKS= Sa Kaeo SutureRBS = Rharb Benthong Suture
ISibumasu (Shan-Thai) Terrane
Terranes derived from Gondwanalandin
Indochina Terrane
South China Terrane
• West Burma Terrane
Regional tectonic setting of the gold deposit (Sone and Metcalfe 2008)
50
CM = ChiangL = Lancang
.,/ Modem
• Alcock
Attenuor Mioc
• Pliocen
Sukhot
lnthan
Region Mesozoi edge co Mawgi
Terranes deriv the late Early P
Sibum
Terranes der the Devonian
Fig.6South China
N
Andaman 10Sea
Mesozoic
• volcanic arc___ Terrane
boundary------- ( nferred)X X X Suture4 4 Active trench
6 6 Thrust & extinct trench
Here is thesimple
subdivision
Terranes of
Cathaysian
affinity and
Gondwana
affinity,
DD
Terranes separated fromGondwanaland in Devonian
Terranes separated fromGondwanaland inEarly PermianTerranes separated from Gondwanaland in Late Triassic-Jurassic
India separated fromGondwanaland in Cretaceous
into
~~
depending uponwhen they
separated from
Gondwanaland.
Cathaysian
terranes are
characterised by
the equatorial
Gigantopteris
flora while
Gondwana
affinity terranes
contain glacial
pebbly
mudstones in
the
Carboniferous•
~~
~~
Blocks _se_Parated fromAustraha m Cenozoic
Blocks of East Asia resulting from South China Sea Tertiary riftingName
sof numbered terranes '
horsts or continental1 = Hainan Island2 = Sikuleh
3 = Paternoster4 = Mangkalihat5 = West Sulawesi6 = Semitau7 = Luconia8 = Kelabit-Longbawan9 = Spratly Islands
fragments
oo
(Dangerous Grounds)10 = Reed
Bank11 = North Palawan12 = Paracel Islands13 = Macclesfield BankC-M = Changning-
Menglian
Suture 100°
fragments, terranes and principal sutures of South-East Asia redrawn from
120° Perm ian 51Fig. 14.1. Distribution of continental
blocks,=W=ak=1ta~a~n~d~M~et~ca~lf~e~(2~00~5~)-~~~~~~~~~~~~~~~~~~~~-·~~~..~..~..~..._..J....
I
Fig.7) SE Asia Regional Tectonic Map with Major Cpmponents Terranes & Fold Belts
SE Asia regionaltectonic mapshowing majorcomponent terranesand fold belts.SRTM data fromhttp://srtm.csi.cgiar.org/; geological mapmodified after e.g.,Barber and Crow(2003), Metcalfe(2013) and Burrett etal. (2014).
52
Fig.8 110"China
ust
,::, ' 0
,,,c:
,,,E SMS
'~ 'e- ' '~ ' '
'
:,V'I
'\
\I I I
I •I :I :I •
II
IIII\\
SOOkm
---
-Outline of Sundaland
Modem spreading centre
Alcock and Sewell Rises
Attenuated continent.al cr or Miocene oceanic crust
Major strike-slip fault zones1 = Gaoligong Shear Zone2 = Chongshan Shear Zone3 = Ailao Shan-Red River
Shear Zone4 = 5againg Fault ZoneS = Mae Ping Fault Zone
20•
Pliocene-Holocene
oceanic crust
Sukhothai Zonelnthanon Zone
Region underlain by accreted Mesozoic oceanic crust. western edge contains WoylaTerranes and Mawgyi Nappe
Terranes derived from Gondwana in the late Early Permian
6 = Three Pagodas Fault Zone7 = Ranong Fault Zone8 = Khlong Marui Fault Zone9 • West Andaman Fault Zone10 = Sumatra Fault ZoneSuture zones
MSS = Myitkyina Suture 10-ASS= Ailao Shan Suture MES ~ Menglian Suture SMS = Song Ma Suture CMS = Chiang Mai SutureNUS= Nan-Urtaradit Suture
Sibumasu (Shan-Thai) Terrane
Terranes derived from Gondwanaland in the Devonian• Indochina
TerraneMS = Mae Sariang
SutureLS = Loei SutureSKS = Sa Kaeo Suture
• South China Terrane
· • West lkirma
Terrana6RS = Bento
-Raub Suture
Geological terrane map of SE Asia (modified fromSearle & Morley 2011) and the distribution of the Sukhothai and lnthanon zones in orthemand SE Thailand proposed by Sonc & Metcalfe (2008) (a. Khlong Lan Bend in the Mac Ping Fault Zone: b. Mae
Yuan Fault).53
CM= Chiang MaiL= Lancang
Cenozoic basin
•
..Fig.10
.. li
If,
'
\Andaman SIBUMA.,. Sea BLOC
"
54
l
97" 98" 100° 102"
PRE-TERT ARY TECTON C UN T0 100 200---======i
EAST SUMATRA BLO (SIBUMASU)
Triassic D Kaloiunconformity
Permo-Ca~boniferous ~ Alas Li(Tapanuh Group) ~ Bohor
(pebbly
MSTZ
WOYLANAPPE
Jurass c- D Woyla
Group retaceous
mestone)- 104°
104°
I I I S IN SUMATRAkm
5'
CK
, Batumilmil, Kualu
mestone (Visean)
ok, Tigapuluh Group mudstones)
Medial SumatraTectonic Zone
3'
2'
,.
o-Island arc and accretionary
1•
Permian D Palepat, Mengkarang
I
data from the 1:250000 geological map sheets published
Fig. 5
Distribution of the pre-Tertiary stratigraphic and tectonic units in Sumatra, based onby the Indonesian Geological Research and Development Centre, Bandung (after Barber et al 2005). Darker
tones indicate areas of outcrop, lighter tones indicate that the pre-Tertiary is overlain by Tertiary and Quaternary sedimentary and volcanic rocks.
55
95°E
S'N
3'
1•
i
O' C
complex
WEST SUMATRA BLOCK
i-s
(CATHAYSIAN)
Triassic D Tuhur
unconformity
Carboniferous0 Kluet, Kuantan (with Visean li
95°E 96" 97" 98" 99'
1 oo
ACCRETIONARY
BLOCK
Bintan Formationr-----~--~-•n•o
(oceanic and volcanic
enc,
:-::,:>
~:,-
-ai ea
~·c
en and Kualu ............
..............................................
,.
<a:w
::::>0
w!=
Formations
limestones)-c
a:
Fig. 6
Stratigraphic relationships between tectonic and stratigraphic units in Sumatra and East Malaya. Triassic rocks in similar facies extend across theEast Malaya, West Malaya-East Sumatra (Sibumasu) blocks, the Medial Sumatra Tectonic Zone and the West
Sumatra block and that all tectonic units arecut by Triassic and younger granites (after Barber et al 2005).
56
WOYLAGROUPWEST SUMATRA BLOCK
(Schiefer Barisan, Vorbarlsan, Kluet and
Kuantan UnHs)
MSTZ
WEST MALAYAEAST SUMATRA
(SIBUMASU)
BENTONG-BILLITON
COMPLEX
en::::>0
ow
~a:
Granitic Intrusions
Granitic Intrusions
u,
jj
!
Granitic Intrusions
----·--------· ...-----·-···---··--
•-•n•Hn-•-••·~
?
?...... ..................................
.
WoytaGroup
arc assemblages)
............................................
Limestone blocks in melange
Qen~
oen$a:I-
SiMup & TuhurFormations
,.
.................. --·-···--·--···-·
Situtup, Silungkang, Palepat and Mengkarang
Formations(tropical Jambi flora)
5
s: Et-=5...... u.....
a,:::,0ex:(!)
-zce
-z
c(/)
:::::,
w e,
Semanggol, Kodlang
Kaloi, Batumilmil
.......F..o...r.m...a..t.i.o..n..s....
··-··-····--······-·-·····
Kaloi and Batumilmil Formations
(.) "!l
=-1
Tempilang
....
Formation ....
-· ........ ··-.....................
....
z~
Q.
~IiJ-
••·············•····················
Pemali Group
a.:::::,0a:e:J:::::,z
~
~ .... 8ryozoen Bed
Bohorok (tilloids) and Alas
Formations (temperate fauna
in limestones)
en
a:
sz
<3
Kluet and Kuantan
(tropical fauna in