II/ c im a cht M Bch H1/ khi qut b Cu Long v M Bch HB Cu Long1.1. Gii thiu v bn trng Cu Long 1.1.1. V tr a l

Hnh 11 Bn phn b cc b trm tch thm lc a Vit NamB trm Cu Long nm ch yu trn thm lc a pha Nam Vit Nam v mt phn t lin thuc khu vc ca sng Cu Long. B c hnh bu dc, vng ra v pha bin v nm dc theo b bin Vng Tu-Bnh Thun. B Cu Long tip gip vi t lin v pha Ty Bc, ngn cch vi b Nam Cn Sn bi i nng Cn Sn, pha Ty Nam l i nng Khorat-Natuna v pha ng Bc l i ct trt Tuy Ha ngn cch vi b Ph Khnh. B c din tch khong 36.000 km2.

1.1.2. Lch s pht trin a chtB trm tch Cu Long l b rift ni lc in hnh, c hnh thnh v pht trin trn b mt mng kt tinh trc Cenozoic. Lch s pht trin a cht b Cu Long tri qua 3 giai on: Thi k trc to rift t Jura mun n Paleocene: l giai on c kt mng trc Tam ca bn, lin quan n s hi t ca cc lc a vo cui Mesozoi m pha tn d ca chng ko di ti Eocen. S hi t ca hai lc a n-c v u- nng ton b thm Sunda ln cao v lm tiu bin hon ton i dng Tethys ng Nam . Thm Sunda pht trin mnh cc di magma xm nhp v phun tro c tui t Juras n Eocen. Cc trng tn d ca thi k Mesozoi cn li l cc thung lng hp hoc cc h nc mn b kh cn. Hot ng mnh m ca magma xm nhp v phun tro xung quanh khu vc bn Cu Long, i km vi cc chuyn ng khi tng, kin to do s va cham ca cc mng lc a, hnh thnh hng lot cc t gy lm phn ct, phn d phc tp b mt c a hnh cui Mesozoi u Kainozoi. Bn Cu Long c hnh thnh trn cc vng st khu vc thuc thi k tin tch gin Paleocen - Eocen. Thi k ng to rift t cui Eocene n cui Oligocene: l giai on tch gin hnh thnh bn trm tch theo cu trc ring. Vo thi k ny, y bn b phn ct bi cc t gy ln thnh to cc khi ko di, sau b b gy bi cc t gy ngang, to nn cc khi nh v khi st, hnh thnh nhiu bn a ho. l n v cu trc c bn bn rift ra la a Cu Long. Cc hot ng tch gin c tng lm cho bn st ln su hn. Trong giai on u, ngun cung cp vt liu trm tch t, iu kin kh hu thun li to nn cc h su vi s tch t cc tng trm tch st h dy trn din rng thuc tp D( h tng Tr Tn di). Cc trm tch giu ct hn thc tp C (h tng Tr Tn trn) lp u bn rift. Vng trung tm bn c b dy trm tch ln, gy ra s st ln trng lc to ra cc tt gy ng trm tch v ko xoay cc trm tch Oligocen Hnh 1-2: cc b trm tch Vit Nam trong phn nn kin to ng Nam Thi k sau to rift: Bt u t Miocen sm n nay, qu trnh tch gin kt thc, ch cn cc hot ng t gy vi cng yu. Giai on bin tin bt xut hin v trn vo bn Cu Long t phn ng Bc, y li trm tch la a v oha Nam.

Vo cui Miocen sm, cc trng trung tm tip tc st ln cng thm s on vng do st ln trng lc ca cc trm tch Oligocen, lm phn ln din tch bn b chm su di mc nc bin. Cc trm tch Miocen di ph chm hu ht ln a hnh Oligocen

Thi k Miocen gia l thi k nng ln ca bn Cu Long, mi trng bin nh hng t hn, phn ng Bc b ch yu chu nh hng ca cc iu kin ven b.

Giai on Miocen mun, bin trn ngp ton b bn Cu Long. Vo cui thi k ny, sng M Kng vo bn Cu Long nn lm thay i mi trng trm tch, ngun cung cp vt liu, kiu tch t v c hnh thi cu trc ca bn. Phn din tch pha Ty Nam ca bn cng c m rng hn v pha ng bng chu th ngy nay.

Thi k Pliocen- T, l giai on to nn bnh cu trc hin nay ca thm lc a Vit Nam. Bn Cu Long khng cn hnh dng cu trc ring m n ha chung vo cu tc ton thm.1.1.3. Cc thnh to a cht.

Bn trng Cu Long gm cc thnh to a cht mng trc Cenozoic, trm tch Eocene, Oligocene, Miocene, Neogene v t. Trong tng mng nt n lm nhim v l tng cha vi khi lng ln du kh trong khi cc tng trm tch Miocene di, Oligocene trn, Eocene trn+Oligocene di l cc tng sinh du quan trng.Mng trc Cenozoic

V mt thch hc, mng c th xp thnh 2 nhm chnh: granite v granodiorite-diorite. Da vo c im thch hc v tui tuyt i, cc mng kt tinh c xp tng ng vi 3 phc h: Hn Khoai, nh Qun v C N.Phc h Hn Khoai l phc h magma c nht c tui Trias mun, granite gm ch yu l amphybol-biotie-diorite, monzonite v adamelit. b bin i, c nt mnh. Phn ln cc khe nt c lp y khong vt th sinh. thuc phc h ny phn b ch yu cnh ca cc khi nng mng nh cnh ng Bc Bch H.

Phc h nh Qun c tui Jura, ch yu l granodiorite, i ch gp monzonite-biotite-thch anh a sc. b dp v v bin i cao, hu ht cc khe nt c lp y bi khong vt th sinh. thuc phc h ny gp ph bin nhiu cu to nh vm Bc Bch H, Hng Ngc, Rng ng, S T en v S T Vng.

Phc h C N l phc h magma pht trin v gp ph bin nht trn ton b Cu Long, c tui Jura mun. Phc h ny c trng l granite thy mica v biotite. b dp v, nhng mc bin i th sinh yu hn so vi 2 phc h trn.

Hnh 13 Ct a tng b Cu Long

TuiH tngc trng thnh hcc trng c sinhPhn b

NeogenePliocene - tBin ngCh yu ct ht trung-mn, lp mng bn, st mu xm nht phong ph ha bin v glauconit mi trng bin nng, ven bGp ph bin cc ha : foraminifera, dng ru, rong to v bo t phn: Dacrydium

Tri u ton b, b dy kh n nh 400-700m, gn nh nm ngang

Miocene trnng NaiCh yu ct ht trung xen k bt v cc lp mng st mu xm, mi trng trm tch m ly-ng bng ven b (pha Ty) v ng bng ven b-bin nng (pha ng v Bc b)Phong ph bo t v nannoplankton, ngho ha foraminiferaB dy t 500-700m, gn nh nm ngang, nghing thoi v pha ng

MiocenegiaCn SnCh yu ct kt ht th-trung, bt kt xen k vi st kt mu xm 5-15m. Trm tch thnh to trong mi trng sng (pha Ty), m ly-ng bng ven b (pha ng, ng Bc)Ph bin cc bo t phn v trng l, rong to nh h tng Bch HB dy thay i 250-900m, gn nh nm ngang hoc un nh theo mt nc h tng Bch H, nghing thoi v pha ng, trung tm b

Miocene diBch HChia lm 2 phn: phn trn gm st kt xm, xm xanh xen k ct kt v bt kt, trn cng l st kt Rotalid; phn di gm ct kt, bt kt, xen k st kt xm, vng, Ha thch bo t phn v t vi c sinh Synedra fondaena. Tp st Rotalid gp ph bin ha thch c trng nhm Rotalia. B dy trung bnh ca h tng 400-1000m, ph bt chnh hp gc ln trm tch h tng Tr Tn

PaleogenOligocene trnTr TnChia lm 3 phn: phn trn gm st kt mu nu-nu m, ct kt v bt kt, ct/st 35-50%; phn gia l st kt nu m, nu en, ct kt v bt kt, ct/st 40-60%; phn di l ct kt ht mnh n th, xen st kt nu m, ct/st 20-50%. Mi trng trm tch ng bng sng, ng bng ven b v h.Ha thch bo t phn F. Trilobata, VerutricolporiteB dy phn trn 200-400m; phn gia 400-1000m; phn di 200-1000m.St kt c hm lng v cht lng VLHC cao n rt cao, l tng sinh du kh tt v l tng chn tt cho mng nt n

Oligocene diTr CCh yu st kt, bt kt v ct kt tch t trong iu kin sng hi khi gp ni la porphyr diabas, gabro diabas, tuf basalt Bo t phn Oculopollis, MagnastriatitesChiu dy dao ng 0-800m.Cc va ct kt cha du kh ch yu trn m ng Nam Rng, S T Trng

EoceneC CiTrm tch vn th: cui sn kt, ct kt a khong, xen bt kt v st kt. Trm tch mu nu , tm, chn lc km c trng kiu molas l tch lc aBo t phn thuc nhm thc vt kh cn: Klukisporires, TriporopolleniteChiu dy c th t ti 600m

M Bch H V tr a l m Bch HM Bch H l m du ln nht hin nay ti thm lc a Nam Vit Nam, nm trn thm i nng trung tm ca bn trng Cu Long, cch thnh ph-cng Vng Tu 120 km v pha ng nam, ni c cc c s cn c k thut - sn xut ca XNLD Vietsovpetro (hnh 1.1).

Hnh 1.1 S phn b cc m du kh trn thm lc a pha nam Vit Nam-c im kh hu thy vn su nc bin ti vng m khong 50m, thun li cho vic s dung cc gin khoan t nng. Cc kt qu nghin cu a cht cng trnh bin cho thy phn trn ca y bin thun tin cho vic xy dng cc cng trnh bin. Cng a chn ca khu vc khng vt qu 6 Richter. Khu vc m c kh hu nhit i - gi ma, ma vo ma h, nhit khng kh 25-350C, ma ng l ma kh vi nhit 24-300. Gi ma ty-nam thng xut hin vo thi gian t thng 6 n thng 10. Thi im c cc trn ma ln khng ko di, km gi lc vi tc ti 25 m/s. m khng kh tng ti 87 - 89%. Ma ng bt u t thng 11 ti thng 3 nm sau vi gi ng-bc l ch yu, tc t 20 m/s, gy nn cc t sng bin cao ti 10 m. Thi gian thch hp tin hnh cc cng vic ngoi bin l ma gi ty-nam: thng 6 n thng 9, v thi k chuyn tip: thng 4-5 v thng 11, khi gi chuyn hng cc dng hi lu ph thuc vo ch gi ma v thy triu. Tc dng chy su 15-20 m t 85m/s, ti tng y: khong 20 30 m/s. Nhit nc trong nm thay i t 25 n 300. mn nc bin dao ng t 33 n 35g/l. Lch s pht trin v khai thc mGing khoan u tin pht hin m l -1, do cng ty "Mobil" khoan vo nm 1975 trn phn vm ca cu to c pht hin theo kt qu thm d a chn 2D. Khi th va, dng du thu c t ct kt thuc Mioxen di. Cc cng vic tip theo c thc hin vo nm 1983, sau khi XNLD Vietsopetro c thnh lp, a n vic pht hin cc thn du ln trong trm tch Oligoxen nm 1985, trong mng nm 1986. thi k u (1983-1987) i tng thm d chnh l cc tng Mioxen di v Oligoxxen, sau nm 1987 l mng. Trc 1992 v tr cc ging thm d c thit k da trn bn cu to, lp theo ti liu a chn thm d 2D, vo cc nm sau, theo ti liu a chn thm d 3D, ln u tin thc hin theo hp ng gia XNLD l vi hng GECO ca Na-Uy vo nm 1991 1992. Trong cc nm gn y (2002-2005), nghin cu m c thc hin ch yu theo ti liu khai thc m, kt qu khoan khai thc, ti x l v ti minh gii ti liu a chn thm d 3D, cng vi mt khi lng hn ch - theo kt qu thm d a chn, kt qu khoan thm d v khai thc sm. Vi mc ch tn thm d cc vng c mc nghin cu thp, tin hnh khoan pha Nam (GK.BH-16, 17, 1201, 1202), Ty-Nam (BH-18) v trn khi ty (GK.BH-11, 12001). Tng cng trn ton m cho n nay khoan c 17 ging tm kim-thm d, trong s 14 ging thu c dng du cng nghip. Mt khoan thm d l 1 ging trn din tch 9 km2M Bch H c a vo khai thc t thng 6.1986. Du c khai thc t cc thn du:- Mioxen di - t 26.06.1986 (ging BH-1)- Oligoxen trn - t 25. 11. 1987 (ging BH-700)- Oligoxen di - t 13. 05. 0987 (ging BH-14)- Mng - t 06. 09. 1988 (ging BH-1) Theo hin trng ti 01. 01. 2006, trn phm vi m xy dng 11 gin c nh v 8 gin nh (hnh 1.2), vi cc h thng bm nn kh cho khai thc bng gazlift v duy tr p sut va. Vic vn chuyn ngi, vt t thit b thc hin bng my bay trc thng v tu bin hoc x lan. Ngun nng lng trn gin c cung cp bi cc ng c t trong. Cn c sn xut ca XNLD Vietsopetro c t thnh ph Vng Tu v c cung cp nng lng nh h thng li in Quc gia t cc nh my in B Ra, Ph M v thnh ph H Ch Minh.

Hnh 1.2 S cng trnh xy dng trn m Bch H

2/ a cht M Bch HM Bch H nm bn trng Cu Long thuc i nng Trung Tm, i nng chia bn trng thnh hai cu to bc hai: pha ng v pha Ty. Trong phm vi ca i nng Trung Tm, Bch H l cu to c trng v c kch thc ln (hnh 2.1.). Ton b cc cu to nng c cu trc phc tp.Trong cu trc a cht ca bn trng trm tch loc nguyn c tui t Oligoxen-Eoxen n t chim u th ph trn mng bng cc bt chnh hp gc v a tng.2.1 a tng Mt ct a cht m Bch H theo kt qu khoan gm cc tng mng kt tinh tui trc tam v ch yu l trm tch loc nguyn (hnh 2.2.1). Tng chiu dy theo chiu thng ng m vo mng l 1990m, ca trm tch l 4740m (BH-11).

Mng l macma kt tinh hon ton vi cc ai mch pocfirit v diabaz anezit bazal phn nh tnh bt ng nht thch hc. Theo ti liu nghin cu mu li cho thy granite biotit hai mica ch yu phn b trong phm vi khi Trung Tm, khi Bc c granodiorit biotit sng xm v adamellit cha nhiu monzonit thch anh, monzodiorit thch anh v diorit kim, khi Nam c granit (BH-8), granodiorit (BH-17) v monzodiorit thch anh (BH-7). mng b bin i th sinh cc mc khc nhau. Trong s cc khong vt th sinh c zeolit v canxit pht trin mnh. Theo s liu phng x, tui tuyt i ca kt tinh dao ng trong khong t 2457 (Triat mun) n 893 (Creta mun) triu nm. Granitoid m Bch H c nt n v hang hc cao. Nhng s liu mi thu c phn ln xc nhn s phn b mng trc y (hnh 2.2.2), cn phn pha nam ca khi pha ty theo s liu nghin cu mu li ca ging khoan BH-11 v mu vn ging khoan 12001 cho thy s pht trin c thnh phn kim l diorit, vi c trng thm cha thp. Mu li ging khoan khai thc 1113 cho thy su 4900m (-4375m tuyt i) c s chuyn tip t phc h granit sang c thnh phn kim.

Mt ct a tng tng hp m Bch HS phn b mng m bch h.

trm tch ph bt chnh hp a tng v gc trn mng c tui Paleogen, Neogen v t c phn chia trn c s cc du hiu thch hc, bo t phn, c sinh a tng theo thang a phng (t di ln): Tr C (Oligoxen di), Tr Tn (Oligoxen trn), Bach H (Mioxen di), Cn Sn (Mioxen gia), ng Nai (Mioxen trn) v Bin ng (Plioxen khng phn chia v t). S thay i ln nht ca chiu dy v thnh phn thch hc l cc tp trm tch c s c tui Olioxen di, chng hon ton vng mt trong phm vi cc khi mng nh cao. ip Tr C (P31) c chiu dy 0-412m nm gia cc tng a chn SH-BSM v SH-11 gm xen k cc va ct kt v cc tp st kt. Cng vi mc ln chm ca trm tch v pha np lm, chiu dy ca h tng tng ng thi vi vic gim c trng thm cha ca cc va ct kt. phn y ca ip l cui v sn kt vi cc mnh mng, to nn tng lt y. Trong mt ct ca ip c cc tng cha du: VI+VIa, VII+VIII, IX, X+XI, vi chiu dy v thnh phn cha khc nhau. Phn u ca cc tng sn phm nm k mt mng. Theo kt qu khoan ging thm d mi BH-11 v ging khai thc nhanh BH-12001 nm vng pha Ty, ti liu a vt l ging khoan v th va xc nh mc nn p gim chiu dy v c tnh thm cha ca chng. Theo ti liu a vt l ging khoan, th va v khoan cc ging khai thc sm (BH-1202) v ging khai thc (BH-1201) vng pha nam th trm tch ca ip ny cng c c tnh thm cha thp, chiu dy cc va ct - bt kt khng ln, hm lng st tng cao. Theo ti liu nghin cu mu li trong c ln vt liu ni la. ip Tr Tn (P32) c chiu dy thay i t 50 n 1800m nm gia cc tng a chn SH-7 v SH-11. ip ny st v st kt chim u th, bn trong bt gp cc thu knh ct kt v bt kt c ghp vi nhau thnh cc tp: Ia, Ib, I, II, III, IV, V. Trong mt vi tp c cc va du. Trong hng lot cc ging khoan gp c ngun gc ni la, thnh phn kim vi chiu dy t n 20m. Ti liu khoan cc ging khoan mi xc nhn quan nim trc y v cu trc v thnh phn ca ip. ip Bch H (N11) c chiu dy t 770-900m nm gia cc tng a chn SH-7 v SH-3. H tng ny gm cc lp mng st, st kt, bt kt v ct kt mu xm, xm ti v mu sc sc s nm xen k. Trn nc ip Bch H trng vi tng ta l tp st montmolinolit v st kt pht trin rng khp din tch vi tn thng dng l st Rotalid. Chiu dy tng ny dao ng t 35m ( pha Nam m) n 150m ( mt vi ging khoan phn ng Nam). Di tng a chn SH-5 trong mt ct ca ip c cc tng sn phm 23, 24, 25, 26, 27 l ct kt thch anh v ackoz. Cc tng sn phm 25, 26, v 27 pht trin th cc thu knh ring bit. Trong lt ct cc ip Cn Sn (N12), ng Nai (N13) v Bin ng (N2 + Q) c lp cc trm tch ct kt - bt kt xen k vi cc tp st bt kt, st v than nu. Khng thy cc tng cha sn phm trong mt ct ca ip ny.2.3 Kin toTheo ti liu a chn 3D v khoan su, cu to m Bch H l khi nng a ly ca mng granitoid b chn vi, chy theo hng nm ng - Bc, m c kch thc 28 x 6km v bin 1400m theo ng ng mc khp kn -4450m. Do s hin din nhiu t gy nn m c cu trc phc tp b chia ra nhiu khi . T di ln trn theo mt ct, cu to phng dn v gim dn kch thc. Bin t gy gim dn n tt hn (hnh 2.3.1- 2.3.2, ph lc 1-16).

pha ty cu to gii hn bi cc t gy nghch F1, F2, F3 c xc nh trn cc mt ct a chn v mt s cc ging khoan nh: 450, 924, 485, 2001, 140, trong c s lp li ca lt ct trm tch. Hng ca cc t gy nghch trng vi ng phng ca cu to. pha ng, khi nng c gii hn bi cc t gy thun F5, F6, F7. cc phn nh chng c phn chia thnh cc t gy nh hn: F 5.1, F 5.2, F6.2, F6.3. Mng c chia thnh cc khi cu kin to (hnh 2.3.5) theo cc t gy chnh c tnh n s phn b thch hc ca mng. - Khi Ty-Bc gii hn pha ng bi t gy thun knh tuyn F8, pha Ty v Nam bi cc t gy nghch F1 v F2, pha Bc bi t gy thun ln F9. - Khi Bc gii hn pha ng bi t gy thun F5, pha Ty bi t gy F8, pha Nam bi ranh gii thch hc ranh gii thy ng hc vi khi Trung Tm. - Khi Trung Tm gii hn pha ng bi cc t gy thun F5 v F5.3, pha Ty bi t gy nghch F3, pha Nam bi t gy thun F6.1 v pha Bc bi ranh gii thch hc. - Khi ng-Bc gii hn bi cc t gy thun F5, F5.3, F6. - Khi ng gii hn bi cc t gy thun F6, F7, F6.3. - Khi Nam gii hn bi cc t gy thun F6.1, F6.2, F6.3 v pha Nam bi ranh gii gi nh gii hn phn cu to c nghin cu.

Hnh 24 S phn chia cu trc Mng m Bch H thnh cc khi cu-kin to

Khi Bc nm su hn so vi khi Trung Tm. khi ny c hai vng nh cao mang tnh a phng c kch thc khng ln khu vc cc ging khoan 810, 811 v 68. t gy ln F4 chia khi ny thnh hai phn. Theo ti liu a chn, bn trong phn pha Ty c mt vi t gy phn nhnh bin nh. Phn pha ng ca khi khng c t gy. Kch thc khi 3.5 x 6 km. Khi Trung Tm chim v tr cao nht v c din tch ln nht trn cu to. Khi ny gm nhiu khi nng a phng nh. Theo ti liu a chn, bn trong khi b chia ct bi nhiu t gy bin nh c hng khc nhau v di khng ln. Kch thc ca khi l 12 x 5 km. Khi ng Bc chm su n 1000m so vi khi Trung Tm, s lng t gy khng nhiu chia ct thnh cc khi nh.a s cc n nghing ln su v pha ng. Kch thc ca khi l 1.5 x 9km. Khi ng ngn cch bi t gy ln F6 theo hng ng -Bc pha Ty. Theo ti liu a chn, trong khi ny ch c vi t gy khng ln v hai trng a phng c su b mt mng n 5200m. Khi Nam, theo kt qu minh gii ti liu a chn nm 2005 khng thy khp kn pha Nam v c gii hn bi ng ranh gii gi nh ca vng nghin cu cu to. Bn trong khi c cc vng nng a phng v nhiu t gy c hng v bin khc nhau. Pha Bc ca khi l phn kt thc ca khi Trung Tm. Kch thc ca khi ny l 10 x 5 km. Khi Ty-Bc pha ng nm k vi t gy thun F4 hng v khi pha Bc. Theo s liu a chn, bn trong khi c t gy nghch ln v hai t gy thun chy ngang v ngn. B mt mng l n nghing chm su v pha Ty. Kch thc khi l 11 x 1.5 km.Cu to ca m theo phc h Oligoxen di c cu trc phc tp hn. Theo s liu khoan v a chn 3D khng c trm tch ca phc h ny phn khi nng cao ca mng. Trm tch ca phc h ny c chiu dy n nh nhng ch khng bng phng mang tnh cc b ca b mt mng. Phn ln cc t gy pht hin mng u pht trin c trong Oligoxen di. Trm tch ca phc h nm k trn mt mng. Trn c s c im cu to, cu trc, phc h Oligoxen di c chia thnh ba vng cha cc thn du, l vng pha Bc, Nam v Ty (hnh 2.3.6). Vng pha Bc c gii hn pha Nam v pha Ty bng ng ranh gii vt nhn ca trm tch Oligoxen di k trn b mt mng, cn pha ng gii hn bi t gy F6. Bn trong vng ny xc lp s hin din ca cc t gy thun F4 v F5 vi nhiu t gy phn nhnh theo nhng t gy ln, vng ny c chia thnh nhiu khi nh: I, II, III . Bn trong cc khi c np un nh c hh thnh do iu kin trm tch. Kch thc cc khi ny thay i t : 7-10 x 1.5 - 2km, ca c vng ny l 6 x 10 km. Vng pha Nam gii hn pha Bc bng ng g k a tng vo b mt mng, pha Ty v ng gii hn theo cc t gy ring bit v ng ng su gi nh -4250m. Bn trong khu vc c mt vi t gy thun v nghch v cc np li nh dng vm. Kch thc vng ny l 4 x 8 km. Khu vc pha Ty gii hn pha Bc v ng bng ng g k a tng ca phc h Oligoxen di vi b mt mng. nhng phn k lin vi mng cu to c dng n nghing v pha Ty, chuyn tip sang np lm vng. Kch thc vng ny l 2 x 4 km.

Phc h Oligoxen trn so vi Oligoxen di c s lng v chiu di cc t gy gim, bin ca cc t gy cn li cng gim, khng cn cc t gy nghch. Cu trc c hnh dng np un b phc tp bi np un nh, mi cu trc v bc thm. Trong phm vi m, cu trc khp kn ch phn cui pha Bc. pha Nam c khi nng mi c chiu su th nm nh phn Trung Tm. Trn c s cha du kh v kin to ca phc h Oligoxen trn, cu trc c chia thnh by khu vc (vng): Trung Tm, Bc, ng- Bc, Ty-Bc, Ty, ng v Nam (hnh 2.3.7). Ranh gii gia cc khu vc mang tnh c l v lin quan n ranh gii pht trin cc tp ct kt. Vng Bc bao gm phn pha Bc ca cu trc, trong c thy s hnh thnh vm c lp khp kn theo bnh -2975m. Ngoi ra, vng ny cn c mt s cc np li nh. Cc t gy n l, bin nh v khng ko di. Kch thc vng 5.5 x 7 km. Vng Trung Tm c phn ra xung quanh mt np un c khp kn bnh -3025 m. Theo ti liu a chn, bn trong vng c cc t gy bin nh, di khng ln v rt nhiu np un nh lm phc tp cu trc ca cu to. Ranh gii pha Bc c vch st vi ng bnh khp kn -3025 m, pha Nam, ng, v Ty theo cc ng c l. Vng pha Nam phn ra xung quanh nhm cc np li bin nh. Theo ti liu a chn, trong vng c cc t gy bin nh, ngn. Cc vng pha Ty v ng bao gm phn cnh ca cu to.

Theo phc h Mioxen di hng cu to gn trng vi kinh tuyn. S lng t gy gim nhiu hn, gc phn cnh cu to gim, hnh thnh ba vm kh r rng: Bc, Trung Tm v Nam (hnh 2.3.8). Tt c cc vm ny b phc tp bi cc t gy ngn.

Thng tin thu nhn c v cu - kin to m cho php rt ra cc kt lun sau:- Cu trc m pht trin tha k. iu ny c thy khi quan st v tr vm cu to ca tt c cc phc h, s thay i chiu dy cc phc h t nh n phn ra, s gim dn ca gc cc tng gim t di ln trn theo mt ct, s gim s lng v bin cc t gy (hnh 2.3.9-2.3.11); - Trn c s phn tch s pht trin cu to xc lp s c mt ba tng cu trc: di-mng trc tam, trung gian v tng nn bn trn;- Tng cu trc phn cch nhau bng cc bt chnh hp;- Cu to b phn chia bi t gy cc loi v c cu trc phc tp.