Tuyen tap bao cao Hgi nghj KHCN "30 nam Dau khi Viet Nam Co hdi mdi, thach thiic moi" 87 TIEN HOA KIEN TAO KAINOZOI SU HINH THANH CAC BE CHlTA HYDROCARBON 6 VIET NAM Ngd Thudng San, Cii Minh Hoang Con[.]
Tuyen tap bao cao Hgi nghj KHCN "30 nam Dau Viet Nam: Co hdi mdi, thach thiic moi" 87 TIEN HOA KIEN T A O KAINOZOI: SU HINH T H A N H C A C BE CHlTA H Y D R O C A R B O N VIET N A M Ngd Thudng San, Cii Minh Hoang Cong ty Thdm - Khai thde Ddu Le Van Truong Cong ty Ddu tw - Phdt triin Ddu TOM TAT Vdo Kainozoi binh dd kien tgo Viet Nam vd Dong Nam A noi chung bi chi phoi b&i sir tdc dong tuang ho cua cdc mdng l&n Au - A, An Do, vd Thdi Binh Duang, kit hgp v&i sir chuyen dong ciia cdc khoi noi mdng Chu ky phdt triin kiin tgo - tu&ng dd vd maema giai dogn De tam la ket qud ciia su va chgm vd hut chim co tinh chu ky giira cdc mdng l&n Khoi Dong Duang bi thuc troi, trugt xuong Dong Nam vd quay phdi, cimg v&i sir gidn day vd lun chim cua Bien Dong, tgo hdng logt cdc bi cdng gidn vd keo todc Chiing dugc phdn bo tap trung doc cdc d&i khdu, thu&ng la ranh gi&i cdc vi mdng, cdc dirt gdy trugt bdng khu vuc, vd tren cdc miin co cdu trite vo Trdi ddt khdc - luc dia, dgi duang vd luc dia bi dgi duong hod Blnh kien tgo Viet Nam vd ke can dugc khong che bai xu thi tru&ng img lire tgo he thong dut gdy tap trung theo ba hu&ng chinh: Tdy Bde - Dong Nam, Dong Bde - Tdy Nam vd phuang kinh tuyen Hogt dong ciia cdc dirt gdy ndy mang tinh nhiiu pha, thua ki tir mong tru&c De tam, phdt trien mgnh & giai dogn Eocen - Oligocen, thu&ng yiu ddn Miocen s&m, ket thiic Miocen muon - Pliocen Nhirng be rift thu&ng phdt trien tren ca sa cdc be giira niu dugc hinh thdnh tru&c Creta muon (?) - Paleogen, gdn lien v&i hogt dong cdc chdu tho, cua song l&n, ddm ven bien, hodc san ho dm tieu Cdc phirc he trdm tich cdt ldng song re qugt chdu thd Oligocen, Miocen s&m, da vdi dm tieu Miocen ciing v&i mdng phong hod, nirt ne tru&c De tam la nhimg ddi tugng tiem udng chira ddu quan & Viet Nam Hau bet cac be chira dau d Viet Nam dugc hinh gdn liln vdi hoat ddng kien tao mang giai doan De tam Chimg phan bd lien ke hoae d noi giao ciia cac ddi khau hay diit gay ldn nhu Sdng Hdng, Sdng Ma, Rao Nay, Tam Ky - Phudc Son I09"k.d., Mae Ping - Hau Giang, Ba Chiia, v.v (Hinh 1) Dac diem kien tao Viet Nam va Ddng Nam A ndi chung giai doan De tam la kel qua tac ddng ciia cac mang ldn - mang ddng An Do, mang chau Uc, mang Thai Binh Duong den ria Ddng Nam luc dia Au - A, kit hgp vdi sy tach gian va phat triln Biin Ddng Tnrdng ddng lyc da tao sy xoay chuyin cac vi mang, sy trugt bdng dge cac ddi khau va cac dirt gay \im Iheo dd cac bl De lam dugc hinh thanh, ddng thdi cung tao tinh chu ky 88 Tien hoa kien tao Kainozoi: Su' hinh cac be chira H y d r o c a r b o n d N'iftJNam^ xen nhting gian doan khu vyc dugc ghi nhan d tat ca cac be Chu ky phat trien kien tao tudng da va maema giai doan De tam lien quan den cac chu k}' va cham va hut chim giira cac mang ldn (Hinh 2) K^ l l l l l ki.nlii;i.Tkiui o / i;.iirn.i.ii: ( I -Jiti t i i ; l{;ll)ll^i•^^i riiDimiitllruc viirl^idirirniilUnDoni-, \ilil.irLl.iil Jninli^iiM^iifiiiiKMit: \ i i \ v : i \ril)'Hhf.ini;i / MiiFiml / Nlnfiis (hi'l j;a\ chiiili (CiinuiiiMi^ivLlliKlth./ni Vi,nyJii,ltn.,-n Nln/ntfliftuv / in( nl>.'iMi: chinh iiiiinJJ.uilJliiuiis MnihiiU'liinKi^ / ~7~\ Kanltl.tiii I rut MHipj^chnil) I ( ' " ^ i fU'-lr';.iiUM'hM.- Irm-latrliiilu i ,——^ i •( ) i Wi i r i i i r t i i l i Kiiiiiii/' \ : i c rljnh : Hinh 1: Ban cau true hien tai ciia Viet Nam va cac viing ke can (PDailly - BP StatoU, 1993 cd chinh bien) Ngudn gdc kien lao ciia cac be tram tich la van de tranh luan, va cd rdt nhilu md hinh dugc nhieu nha dia chat de cap (N.X Bao, L.D Bach, N.D Cat, V.D Chuong E.N Lai, P.H Eong E.V Manh, T Nghi, P.V Quynh, N.T San, P.T Thj, N.G Thdng, T Trgng Thang N.T Kim Thoa, T.V Tri, C D Trilu, N.X Timg, N.T Yem, v.v ) nhung deu nghieng ve thuyet kien tao thiic trdi (Tapponnier et al., 1982) Lanh thd Viet Nam va ke can la mien cau triic lien hgp phirc tap cd kieu vd luc dja, mac dti dii dugc cd ket va trd mdt craton hgp nhat vdi lyc dia Au - A vao cudi Mesozoi (Jura mudn - Creta?) nhung boat ddng hut chim ciia mang An Do Duong d ria Nam cung dao Tuyin tap bao cao Hoi nghj KHCN "30 nam Ddu Viet Nam: Co hoi mdi, thach thiic mdi" 89 Sumatra-Java, va dac biet sy gian day va dai duong boa Bien Ddng, nen vo luc dia ria Ddng mang Au - A bj biin ddi manh vao Kainozoi - dd la nguyen nhan tao sy khae biet CO cbl va lich sir hinh cac be De tam chira dau d Viet Nam va ke can 90° ' I I I 150° E 6tfN I Cfing gian vdo KaJnozcri —I1 V4 V«d»iil dfi duong Bi^n Dftng ' vkvhbiia biin Andaman I Ditlltn Hinh 2: So' kien tao thiic troi va cac dih gay Ion o Dong chau A va Kainozoi Cd the chia cac mien cau true vdi cac dang vd Trai dat nhu sau (Hinh 3): • Cdu trdc vd luc dia: • Mien cau true vd luc dia Viet - Trung • Mien cau true vd luc dja Ddng Duang • Mien cau triic vd luc dja Sibumasu • Cdu true vd luc dia sdt bj dgi duong hod: • Mien cau triic vd luc dia sdt bi dai duong hoa Hoang Sa - Macclesfield gian day Bien Ddng • Mien cau true vd luc dia sdt Trudng Sa - Reed bank bj dai duang hoa tach day Bien Ddng 90 Tien hoa kiln tao Kainozoi: Sy hinh cac b^ chiia Hydrocarbon d Viet Nam 104" 108** iia^* 116° lao** 108" 112 116° 120° 20' 16° 12' 80 104 ^ l le ——T-TwSB ^ ""T 1-" 20 24 E.-' '-a*iM ^1' 28 " ' l' 32 Hinh 3; So' phan bo cac mien cau true sau vo Trai Dat (Chieu ddy vo Trdi Ddt, vi tri nui lira, cdc dirt gdy chinh dua theo tdi lieu N.N Trung N T T Hirang (2003) kel qud phdn tich phdn mem ve linh I Mien cdu tnic vd luc dja Viet - Trung II Mien cdu true vd luc dia Ddng - Duang III .Mien cdu tnic vd luc dia Siinoburma IV Mien cdu tnic vd dgi duang Bien Ddng (hien Nam Trung Hoa) V Mien cdu triic vo luc dja sdi bi dgi duang hod Hodng Sa - Macclesfield VI Mien cdu trite vd luc dia sdt bi dgi duang hod Truang Sa - Reed hank • Cdu true vd dgi duong: • Mien cau true vd dai duang Bien Ddng Dti cd ngudn gdc khae nhau, nhung cac bl dugc tao lien quan din sy chuyin ddng trugt bang, cang gian ben mang va cd dang graben, hoae nira graben vdi cac chu ky tram tich va nhirng bat chinh hgp, ddng tudi vdi dugc quan sal thdy tdt ca cac be (Hinh 4) Mdi IrutTng tram tich va quy luat phan bo ddu dugc khdng cbl bdi hai ylu to chuyen ddng kien lao ciia cac vi mang ndi luc va sy dao ddng cd tinh chu k\ cua myc nude dai duong Sy dao ddng myc nude dai duong, dac biet vao Oligocen - Miocen ddng vai trd quan trgng sy phan bd tudng tram lich \'a dac tinh dau Tu>in tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co hdi mdi, thach thiic mdi" 91 Tiln hda kiln tao ciia cac be tram tich chira dau Kainozoi d Viet Nam cd the dugc chia ba giai doan: tien rift trudc Eocen giira (?), tao rift Eocen giira - Miocen sdm sau rift Miocen giira - hien tai CKil HE niONG PHii'niONC DtTlJ Bic Be° sang NamBesdr^ Bl'CiJu BcNaraC6n Honj Uong long Son BSMaLai-TTio Chu IT5v Nam Tuoi vacham Viel Nam) i Pliocen (N;l Vinh N: BienDong Miocen Nr Bien Dong Dong Tien Quang Dong Nam Con Minh Hifng Ngai Nai Sdn Hai Con Tliong- Sdn MangCau N/ N Bien Bien Dong Bio Phu Tri Cl) Ton Dam Giai doan lid ihuc mii Ddi rang bien Nam Trung Hoa (N,) Phong Song Bach Chau Hi/dng Ho Ngoc Ni' Hien Difa u Dinh Tra Giai doan chinh ciia qua in nh Cao Tan md nine bien Nam Trung Hoa E,: (Kj) E Bach F.il Tri Giai doan hop nhal cac mang chinh Tra Kim (md rdng bien Nam Trung Hoa kcl Cii Cau Phil Ca Tien Coi Long ihiic su md rdng bien An Do Dudng) Mang AnDoiaiaomangAuA K; iw'flc K? Da mong Hinh 4; Bang lien ket dia tang cac be tram tich Viet Nam • Trudc 50 trieu ndm (trudc Eocen giua) - Giai dogn tiin rift Vao cudi Creta (90 tr.n.) lanh thd Ddng Duong da dugc gan ket vdi Nam Trung Qudc cau ria Nam ciia lyc dia ben viing Au - A (Hinh 5) Theo md hinh trugt bang trai dge dirt gay Sdng Hdng thi vi mang Ddng Duong dugc tinh loan nam d vi tri 500km xa ve Tay Bae so vdi hien tai khoang vT 15" - 20" bae va cd true cd tir nam lech 20" - 30" sang trai so vdi hien tai Cac dirt gay Sdng Hdng, 109"k.d bat dau boat ddng tao dieu kien cho khdi Ddng Duong xoay phai va trugt xudng Ddng Nam Dge cac dirt gay hinh cac trung sut graben gitra niii lap day cac tram lich luc dia Paleogen - Eocen nhu trting Ha Ndi Sy trugt bang ciia khdi Ddng Duong lien tuc xudng Ddng Nam, ket hgp vdi sy gian nd nhiet dudi vd Trai dat d khu vuc Bien Ddng hien tai da lam tach gian khdi Hoang Sa - Trudng Sa, mdt bd phan cau true trudc De lam ciia vi luc dia Ddng Duong de bat dau su gian day va hinh Bien Ddng cd cau triic vd dai duong nhu Va ciang tir thdi diem bat dau hinh cac mien cau Iriic cd vd luc dia sdt bi dai duong hda Hoang Sa - Macclesfield d phia Bae va Trudng Sa Reed bank d phia Nam Dia khdi Indosinia va phan Tay Ddng Duong cd vi tri cd ndm xa ve Ddng BSc so vdi hien tai va dugc xem la khu vuc nane cao Tien hoa kien tao Kainozoi: Su hinh cac be chii'a Hydrocarbon d^^j^t Nam 92 \ \ \ ///// \J I Mang An DO Dj thtfcTng cd tir Viing bj nen ep I Vi tri c6'dja ly Ddi gian day '^ I Ddi hut chim Viing cdng gian Vj tri hi^n cua d^'t li^n / / T2 I Hirdng djch trir^r Cdc dih gay chinh xdc djnh gia djnh Vj tri cd' dgi dufdng Hinh 5: Vi tri co khu vuc Dong Du-ong va ke can diroc lap lai cho thoi ky tien rift Eocen som (tru'oc 50 trieu nam) theo T.Y.Lee; L.A.Lawver (1993) co bo sung Sy cang gian ciia ria khdi Viet - Trung ve Ddng Nam tir sau Creta va manh nh^t Eocen sdm da tao mdt loat graben hep, keo dai hudng Tay Nam - Ddng Bae va dugc lap day bdi cac tram tich molas giiia nui, tao phirc he lien rift tudi Creta mudn Eocen sdm Cac triing giiia nui Creta - Paleogen sdm dugc ghi nhan hinh tren ria Nam vi mang Viet - Trung (Ldi Chau, Qiangdongnan), va tren cac mang sdt vi luc dia Tuygn tap bao cao Hdi nghj KHCN "30 nam DSu Viet Nam: Co hdi mdi, thach thuc mdi" 93^ Hoang Sa - Macclesfield, va Trudng Sa, tren dd se tiep tyc phat trien cac he ddng rift Oligocen - Miocen sdm Vi mang Bien Ddng cd cd cau tnic vd dai duong tiep tyc di chuyen xudng phia Nam va but chim dudi khdi Borneo d ria Tay Bae Phuc he tien rift Paleogen - Eocen sdm cd le cting tdn tai cac trting sut hep giiia nui d phan sau nhat trung tam cac be Cim Long va Nam Cdn Son Nhin chung, giai doan - trieu nam, lanh thd Viet Nam va phan ldn Ddng Duong dugc dang cao, phan di manh, tao birc tranh xen ke gitra cac ddi nhd dia liiy thudng dugc cau tao bdi cac the batholit granit, granodiorit, da niii lira xen vdi cac triing giija niii phan bd dge cac ddi khau hoae dirt gay ldn khu vyc Phirc he tiln rift dac trung bdi tudng lyc dia chi tdn tai cac trting giOa niii, ngan each bdi dut gay Chuyen ddng kien tao cudi Mesozoi - dau De tam lam tai boat ddng cac he thdng dirt gay, tao he thdng nirt ran da mdng Idt dudi cac trGng De tam va chi phoi binh cau true cac trting Cting thdi gian nay, ldp vd phong hda day dugc hinh tren cac mdng nhd granit Dd la cac tien de quan trgng va thuan lgi cho tich tu dhu cac be tram tich De tam • Thdi gian 50-17 trieu ndm (Eocen giiea - Oligocen - Miocen s&m) - Giai dogn tgo rift Vao thdi diem khoang 50 - 45 trieu nam, gitia Paleogen - Eocen xay su va mang giija mang An Do va Au - A, rut ngan vd Trai dat, va hut chim mang An Do duong dudi ria Nam luc dia Au - A Sy va mang danh dau pha tao niii - udn nep chinh ciia chu ky kien tao Himalaya, lam tai boat ddng lai cac dut gay sau tdn tai trudc dd, thuc trdi mang Ddng Duong ve Ddng Nam, tao cac be rift ven cac ddi cat trugt Giai doan tao rift cd the dugc bat dau tir Eocen giiia, ket thiic vao Miocen sdm, nhung ddi nai hien tugng syt rift cdn dugc ghi nhan den cudi Miocen giiia Cd tac gia phan giai doan tao rift hai thdi ky: thdi ky Eocen giiia - Oligocen la thdi ky tao rift thyc thy hay cdn ggi thdi ky ddng rift, va thdi ky Miocen sdm, cdn dugc ggi thdi ky phat trien rift mudn • Thdi gian 50 - 25 trieu ndm (Eocen giiea - Oligocen) (Hinh 6) Sy va mang gitra mang ddng An Do va Au - A, dac biet d thdi ky cudi Eocen giQa (43 trieu nam) cd sy va mang cimg da thiic trdi cac mang Viet - Trung, Ddng Duong trugt ve Ddng Nam dge theo cac dut gay sau trugt bang, tai boat ddng lai nhu Sdng Hdng, Tam Ky - Phudc Son, Mae Ping, Ba Chiia, 109°k.d tao loat be va triing, chu yeu dang keo toac va cang gian lap day cac tram tich dam hd, chau thd Sy trugt bang trai dge he dut gay Sdng Hdng va trugt phai dge he diit gay Rao Nay, Tam Ky - Phudc Son da tao hudng nen ep BSe - Nam va cang gian Ddng - Tay de hinh be Sdng Hdng cd dang nen ngang d phan dat lien va cang gian d vinh Bae bd (Hinh 7) O vinh Thai Lan va Malay, theo md hinh kien tao thuc trdi ciia Tapponnier vdi xu thi xoay phai va dich chuyen xudng Ddng Nam toan khdi Ddng Duong, thi chuyin ddng trugt dge cac dirt gay Maeping - Hau Giang va Ba Chiia da nhilu l§n thay ddi hudng theo thdi gian Nhieu tac gia cho sy trugt bang trai di kem nen ep huang Ddng Tay da xay tir dAu Eocen, nhung sy phat trien cac rift graben chi nhan ro tir Oligocen sdm din gitra 94 Tien hoa kien tao Kainozoi: Su' hinh cac bl chu-a Hydrocarbon d Vigt_Nam^ Miocen chuyen ddng trugt dge cac diit gay Mae Ping - Hau Giang va Ba Chiia thay ddi sang hudng trugt phai tao sy cang gian hudng Ddng Tay lam phat sinh loat triing va be dang cang ngang va keo toac xen giiia cac ddi nhd dia luy nhu cac trting d mien trung Thai Lan, bl Pattani, be Malay (Hinh 8) them lyc dia Nam Viet Nam, cac be Cim Long va Nam Cdn Son dugc hinh tir cudi Eocen sy thiic trdi khdi Kontum ve Ddng Nam da tao sy cang gian xd tam (R Hall, 1997) hudng Tay Bae - Ddng Nam, tao cac triing syt graben d ria khdi, dugc lap day bdi phiic he synrift Eocen mudn - Oligocen tudng lyc dia, sdng, dam lay ven bien, xen cac khdi nhd ciia mdng dugc phii bdd set dam hd, ddng vai trd sinh va chan dau quan trgng he thdng dau khu vyc Cac khdi nhd mdng trai qua thai gian dai bi phong boa, ddng thdi chiu tac ddng ciia sy cang gian va nen ep bien ddi cd tinh chu ky sy thay ddi hudng cua trudng ling lyc, tao he thdng niit ran quan trgng lam tien de cho cac tich ty dau Tdc trugt bang xudng phia Nam khdng deu theo thdi gian, tao hien tugng "roll back velocity", cd the la nguyen nhan ciia sy thay ddi trudng iing lyc tao sy cang gian va sut liin manh vao Eocen - Oligocen sdm, sau dd la sy nen ep va nang len, ddi noi cd nghich dao kien tao vao cudi Oligocen • ,n Hinh 6: Vj tri co khu vu-c Dong Dirong va ke can du-ffc lap lai cho thoi ky dong - rift Eocen muon - Oligocen (35-30 trieu nam) theo T.Y.Lee, L.A.Lawver (1993) co bo sung Tuygn tap bao cao Hdi nghj KHCN "30 nam Diu Viet Nam: Co hdi mdi, thach thuc mdi 95 Vao giGa Eocen, su gian day tiep tyc d Bien Ddng, day xa dan khdi Trudng Sa Reed bank xudng phia Nam Pha gian day dugc ghi nhan manh va rd nhat vao Oligocen theo hudng Bae Nam Khdi Bien Ddng cd hinh trudc dd giam dan dien tich tiep tuc dich chuyen xudng phia Nam, bi hiit chim va tieu bien dudi ria Tay Bae Borneo Hinh 7; Ban lire khu vyc Dong Nam A 96 Tien hoa kien tao Kainozoi: Su' hinh cac bl chu-a Hydrocarbon 6_Vi|tJ^J5ni lOTE I LF OF T H A I L A N D TRANSTENSIONAL OEXTRAL SHEAR ã>ãô Basins are annotated as follows: S.iKHO.W P.4K.\:4M m^.4 HIN V WESTERN PR4.CHU.AP WESTERN KR4 P.4TT.ANI CHl'AfPHO.W 10 N.AKHON 11 SO.XGKHLA 12 MALAY 13 KHMER 14 EASTKRA Hinh 8: So- cac bi De tam o* Vinh Thai Lan (theo R.D.Shau, 1997) Sy cang gian cting tao he thdng diit gay a vT tuyen, Ddng Ddng Bae - Tay Tay Nam tren mien cau tnic Viet - Trung va cac khdi lyc dia sdt Hoang Sa - Macclesfield va Trudng Sa - Reed bank, dge theo dd mdt loat graben rift Oligocen dugc hinh rieng biet hoae chdng gdi tren cac trting giiia niii Creta - Eocen sdm phat sinh trudc dd He dirt gay a vT tuyen ciing he diit gay hudng Tay Nam - Ddng Bae boat ddng trd lai, chi phdi boat ddng kien tao - tram tich cac be Ldi Chau, Qiangdongnan (Wenchang B.) ria dia khdi Indosinia, sy trugt bang theo hudng Bae Nam dge theo he dirt gay 109°k.d hinh mdt loat trting sut cang ngang hep keo dai dge sudn luc dia -bl Phu Khanh dugc lap day bdi phiic he synrift tudi Oligocen Cac trting cd dang graben hoae Tuygn tap bao cao Hdi nghj KHCN "30 nam DSu Viet Nam: Co hoi mdi, thach thiic mdi' 97 "nira graben", xen giiia cac ddi nang hep dugc ngan each bdi nhung dirt gay trugt bang ddc, thudng di kem boat ddng niii lira tre Cac tram tich Paleogen dam hd dugc xac djnh la ngudn sinh dau tiem nang d cac trting (Hinh 9, 11) N I - 14° 13° 12° Km 109° 110 Hinh 9: Ban cau tao be Phii Khanh - Mat bat chinh hop rift Vao cudi Oligocen, sy va mang gitia luc dia chau Uc va cung dao Sunda da tao trudng nen ep, gay nghich dao kien tao dudi dang chuyin ddng phan di dge cac dirt gay thuan, kit thiic pha tao rift thyc thy, hinh bk chinh hgp khu vyc cudi Oligocen cac be "ndi luc" ria vi mang Ddng Duong Sy tach gian va dai duong hoa ciia Biin Ddng, dac biet d phhn Tay Nam, ciing vdi boat dgng trugt dge dirt gay 109°k.d da gay hien tugng phun trao bazan va andesit tuong ddi phd biin cac bl tilp giap vdi ria Tay va Tay Nam Biin Ddng 98 Tien hoa kien tao Kainozoi: Su hinh cac bl chiia Hydrocarbon o^VigtJNam^ Nhin chung phirc he tram tich Eocen - Oligocen dugc xac dinh "ddng rift" Hen quan den thai ky sut rift thuc thy lich sir phat trien cac bl tr^m tich De tam Su sut liin nhanh vdi tdc vugt trdi bii lan tram tich da tao dilu kien cho su phat triln va tri lau dai dieu kien hd va dam lay ven bien phong phii vat chk huu co h\ chdn viii nhanh, dia hinh ven hd thudng thap, tham thuc vat dugc phat trien dilu kien bau am - dd la ngudn vat chat hiru co phong phu tudng hd thuan lgi cho sinh dhu Hinh phirc he tram tich cat set vira la ddi tugng sinh dhu tilm nang dong thdi cting la tang chira dau quan trgng cac be De tam d Viet Nam Hinh 10: Vi tri co khu vuc Dong Duong va ke can diro'c lap lai cho thoi ky ding rift Miocen som (20 trieu nam) theo T.Y.Lee, L.A Lawver (1993) co bo sung • Thdi gian (25 -17 trieu ndm) Miocen s&m Vao Miocen sdm, sy syt rift hau nhu cham dut tat ca cac be trudc va sau cung dao Sumatra Ddng Java, Nam Borneo, thi rieng d cac be ndi luc can cac ddi khau tren Tuygn tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co' hoi mdi, thach thiic mdi" 99 mien cau true Ddng Duong va Viet - Trung qua trinh van tiep tuc nhung cudng yeu di, lao thdi ky phat triln rift mudn cac be Chuyen ddng kiln tao Miocen sdm cdn dugc dac trung bdi dgt cao trao gian day mdi va tiep tuc md rdng Bien Ddng lanh nhiet tao sut liin khu vyc, kem sy dang cao myc dai duong da gay hien tugng bien lien tren tat ca cac be Paleogen hinh ven Biin Ddng Dien tich tram dgng dugc md rdng ngoai ranh gidi cac miin sut liin Paleogen, nhung cudng hoat ddng dirt gay chi phdi sy sut lim ylu di Dieu kien bien phat trien tren phan ldn cac bl ria Ddng vi mang Ddng Duong nhu Phil Khanh, Nam Cdn Son, Tu Chinh - Vung May tao phirc he Irhm tich carbonat va san hd am tieu va timg thdi ky \hn sau vao cac bl Sdng Hdng, Cim Long va Ma Lai Thd Chu, hinh phirc he dam \hy, re quat chau tho va biin ndng ven bd Dge dirt gay 109°k.d cac triing ep ngang hinh Oligocen md rdng dhn dien tich sy liin chim ciia Biin Ddng Vao cudi Miocen sdm, tdc syt liin dugc bii ISn ngudn cung cap vat lieu tir dia khdi Kontum bi bde mdn, tao nhtrng tap tr^m tich alluvi lan tiln tren cac dam rdng ldn ven biin He chau thd \hn tiln cdn phat triln tilp sang thdi ky Miocen trung Cac re quat va cac vat nhgn myc nude th^p dugc xem la nhung ddi tugng tiem nang chira dhu (Hinh 10) Hinh H; Mat ck dja chan qua bl Phii Khanh (ngudn PVEP) Sy chuyen ddng trugt bang trai dge he dirt gay Sdng Hdng, Ba Chiia chhm dirt (H.Wu,1989) d khoang thdi gian 20 trieu nam, ddng thdi cung kit thuc sy thiic trdi va trugt cua vi mang Ddng Duong vl Ddng Nam Chuyin ddng cang gian va sut liin phan di ddng tram tich cung yeu di vao cudi Miocen sdm d da sd cac bl va trung ven khdi Ddng Duong, gay bat chinh hgp khu vyc gitia Miocen sdm va giua 100 Tiln hoa kiln tao Kainozoi: Su- hinh cac bg chiia HydrocarbonjyN^i|lJ^jJii!]L Sy gian day ciia Bien Ddng tilp tuc day khdi Trudng Sa - Reed bank di chuyen xudng phia Nam hut chim dudi Borneo, lao loat triing va be nen ngang tudi Miocen d phhn Ddng khdi Trudng Sa dugc lang dgng cac tram tich da vdi, san hd am tieu Lien quan din sy gian day tiep tyc cua Bien Ddng vao Miocen, tren khoi Hoang Sa Macclesfield cac bl ivhm tich Paleogen dugc md rdng, dac biet, bl Hoang Sa cd mang true nip udn va diit gay bi c4t cyt dang dudi ngya noi tiep giap vdi khdi nang ria dge dirt gay trugt bien dang 109°k.d Cac phirc he tvhm lich carbonat san hd am tieu, cac da lyc nguyen tudng doi cat ldng sdng, re quat chau thd myc thap, bai ven bien la nhung ddi tugng tiem nang chiia dau Miocen sdm • Thdi gian Miocen giu'a - Pliocen - De tw (sau 17 trieu ndm) - Giai dogn sau rift Giai doan dugc dac trung bdi sy cham dirt hoan toan chuyen ddng thuc trdi ciia vi mang Ddng Duong vl Ddng Nam, sy ddi hudng dich chuyen tir trugt bang trai sang trugt bang phai dge cac dirt gay Sdng Hdng va Ba Chiia, cham dirt syt rift dang graben va nira graben dl chuyin sang cbl syt bdn tren hau het cac be tram tich De tam hinh trudc dd (Hinh 12) Sy va mang giOa khdi Bae Palawan vdi Kalimantan d thdi gian 17 trieu nam cham dtit sy gian day dai duong d Bien Ddng Qua trinh ngudi keo dai ciia vd Trai dat lam mang Bien Ddng va lan can bi liin chim sut rift, myc nude dai duong dugc dang cao tao bien tien khu vyc Xen giiia giai doan nay, vao dau Miocen mudn xuat hien pha tang nhiet ngan ciia vd Trai dat khu vyc Bien Ddng va ke can, cimg vdi sy gia tang tdc trugt phai dge cac diit gay chinh Sdng Hdng va Ba Chiia da gay nghich dao kien tao hau bet cac be tram tich De tam ven Bien Ddng va tao bat chinh hgp khu vyc Miocen mudn Vi the, cd tac gia da chia giai doan pha: trudc va sau nghich dao kien tao Miocen mudn (3 Viet Nam, hien tugng nghich dao kien tao Miocen mudn the hien rd nhat d be Sdng Hdng, dac biet phan dat lien, va Nam Cdn Son Nghich dao kien tao Miocen mudn la dang cau true rat dac trung d Ddng Nam A vao giai doan De tam, vi the nhieu tac gia (Eubank va Makkie, 1981; Letouzey, 1990; Ginger va n.n.k., 1993) cdn ggi "udn nep Sunda" O nhieu noi, cac nep udn nghich dao bi vat bdi bat chinh hgp khu vyc Mio - Pliocen Trong cac be d them Sunda, cac nep udn nghich dao thudng la cac bay chira hydrocarbon Vao Miocen giiia, chuyen sang giai doan sau rift, xay hien tugng ngudi nhiet ciia vd Trai dat d vimg Bien Ddng, gay lun chim ciia them luc dia va tao cao trao bien tien khu vuc d cac viing sut trudc dd tren ria Nam khdi Ddng Duong Hinh phirc he set biin va da vdi Miocen gitia phd bien hau bet cac be De tam ven ria Bien Ddng Bien tiln ciing phii tren loan ria luc dia Nam Trung Hoa Trong cac be Hoang Sa va Tu Chinh Vung May, Trudng Sa - Reed bank, cac tr^m tich Miocen giQa - mudn, Pliocen dugc dac trung bdi tudng da vdi san hd am tieu va set biin bien sau, cac turbidit Trong cac bl ndi luc, phat trien cac tvhm tich luc nguyen bien ndng, ven bd Vao Miocen mudn - dhu Pliocen khoang 12 trieu nam, xuat hien pha tang nhiet ngan cua vd Trai dat lao phun trao bazan phd biin rdng khap d dia khdi Indosinia, dge ddi nang Tuygn tap bao cao Hdi nghj KHCN "30 nam DSu Vift Nam: Co' hdi mdi, thach thuc mdi' 101 ria ven dirt gay 109\.d., d dao Hai Nam, va dge vting ven bien Nam Trung Qudc Phun trao bazan dat dinh cao vao Pliocen Hinh 12: Vi tri co khu vifc Dong Dirong va ke can diro'c lap lai cho giai doan sau rift Miocen muon (sau 10 tr.nam) theo T.Y.Lee, L.A Lawver (1993) co bo sung Phiic he tram tich cat bien tien, da vdi am tieu, turbidit, cac diapir set, hinh trudc nghich dao la cac ddi tugng chiia dau khi, dac biet la Miocen gitia - mudn Ven khdi Borneo phd bien he dku cd tudi chii ylu Mio - Pliocen Cac he thudng la cac re quat chau thd dugc hinh cac bl nam tren vd dai duong (bien Celebes, bien Sulu) hoae ria mang dai duong hay vd ria luc dia bi biin ddi (Kutei, Baram, Sabah, v.v.) He dSu dy doan cung cd thi tdn tai d cac bl Hoang Sa, Phu Khanh, va Tu Chinh - Vting May 102 Tiln hoa kien tao Kainozoi: Su- hinh c^c bl chu^ Hydrocarbon dA;i|t_Njn KET LUAN Chuyin ddng Indosini kit thuc bang pha tao niii Yin Son cudi Creta da gan ket cac vi mang Ddng Duong, Viet - Trung vdi khdi thdng nhit, md rdng luc dia Au A xudng phia Nam Vao Kainozoi, binh dd kiln tao Viet Nam va Ddng Nam A ndi chung bi chi phdi bdi sy tac ddng tuong hd ciia cac mang ldn Au - A, An Do, va Thai Binh Duong, ket hgp vdi sy chuyin ddng cua cac khdi ndi mang Chu ky phat trien kiln tao - tudng da va maema giai doan De tam la kit qua ciia sy va cham va hiit chim cd tinh chu ky giiia cac mang ldn Khdi Ddng Duong bi thiic trdi, trugt xudng Ddng Nam va quay phai, ciing vdi sy gian day va liin chim cua Biin Ddng, tao loat cac bl cang gian va keo toac Chung phan bd tap trung dge cac ddi khau, thudng la ranh gidi cac vi mang, cac dirt gay trugt bang khu vyc, va tren cac miin cd chu true vd Trai dk kbac - lyc dia, dai duong va luc dia bi dai duong boa Chuyin ddng trugt bang va cang gian ciia cac vi mang da tao cac be rift dang graben hoae nira graben vdi cac chu ky trim tich va nhiing bat chinh hgp ddng tudi vdi quan sat dugc tat ca cac be Binh dd kiln tao Viet Nam va ke can dugc khdng che bdi xu the trudng iing lyc tao he thdng dirt gay tap trung theo ba hudng chinh: Tay Bae - Ddng Nam; Ddng Bae - Tay Nam va phuong kinh tuyen Phuong vT tuyen it phd bien ban va cd le la he dirt gay di kem vdi cac dirt gay trugt bang Tay Bae - Ddng Nam Hoat ddng ciia cac dirt gay mang tinh nhieu pha, ke thira tir mdng trudc De tam, phat trien manh nhat d giai doan Eocen - Oligocen, thudng yeu dan Miocen, ket thiic Miocen mudn - Pliocen, lien quan den hai thdi ky cang gian Eocen - Oligocen va Miocen sdm tao sut liin rift di kem hai pha nen ep: vao cudi Oligocen tao sy chuyen ddng phan di nang len cac trting va pha nen ep vao Miocen mudn tao sy nghich dao kien tao va hinh cac nep udn nghich dao mdt sd be tre ma boat ddng cd lien quan den sy gian day cua Bien Ddng Nhiing dut gay cdn tac ddng den sy hinh va phan bd cac day nang cau tao ben cac be; tao he thdng cac dirt gay phu di kem cd vai trd quan trgng he thdng dau khi, dac biet tham gia tao he thdng nut ne mdng trudc De tam NhGng be rift thudng phat trien tren co sd cac be giiia niii dugc hinh trudc dd Creta mudn (?) - Paleogen, gan lien vdi boat ddng cac chau thd, cira sdng ldn, dam ven bien, hoae san hd am tieu Cac phiic he tram tich cat ldng sdng re quat chau thd Oligocen, Miocen sdm, da vdi am tieu Miocen ciing vdi mdng phong boa, nirt ne trudc De tam la nhOng ddi tugng tiem nang chiia dau quan trgng dr Viet Nam Tuygn tap bao cao Hpi nghj KHCN "30 nam Dgu Viet Nam: Co hdi mdi, thach thiic mdi" 103 TAI LIEU THAM KHAO Hall R., 1997 Cenozoic plate tectonic reconstruction ofS.E Asia Petroleum Geology of S.E Asia Ke Ru, John D Pigott, 1986 Episodic rifting and subsidence in the South China Sea AAPG Nielsen L.H., Mathiesen A et al., 1999 Modeling of hydrocarbon generation in the Cenozoic Song Hong basin Vietnam, a highly prospective basin Journal of Asia Earth Science 17 Roques D., Matthews S.J., Rangin C , 1997 Constraints on strike-slip motion from seismic and gravity data along the Vietnam margin offshore Da Nang, implications for hydrocarbon prospectivity and opening of the Vietnam sea Petroleum Geology of SE Asia Shaw R.D., 1997 Some implications of Eurasian and Indo- Australian plate collision on the petroleum potential of Tertiary intracratonic basins of SE Asia Proe of Int Conference, Jakarta, Indonesia Tapponier P., Peltzer G et al, 1982 Propagating extrusion tectonics in Asia: New insights from simple experiments with plasticine Geology, Vol 10, December Tran Van Tri, 1992 The geotectonic framework of Vietnam and adjacent areas Proe of the 29"" Annual Session CCOP - November 1992 Tung-Yi Lee, Lawrence A Lawrer., 1994 Cenozoic plate reconstruction of the South China sea region Tectonophysics, p 235 Pham Huy Long va n.n.k., 2002 Lich sir tiin hod dut gdy ldnh thd Viet Nam Dja chit tai nguyen mdi trudng Nam Viet Nam, Tp Hd Chi Minh 10 Le Van Manh, Ta Trgng Thang, 2000 D&i dirt gdy sdu Sdng Hdng Id d&i khdu kiin tgo cd cd lich su phdt trien lau ddi Tap chi cac khoa hgc Trai dat 4, T 22 I.Nguyen Van Vugng va n.n.k., 2002 Mot mo hinh dgng lire m&i cua cdc biin dgng Kainozoi doc d&i dirt gdy trugt cdt Song Hdng Tap san Dja chat, Loat B, Sd 19 - 20 ... them lyc dia Nam Viet Nam, cac be Cim Long va Nam Cdn Son dugc hinh tir cudi Eocen sy thiic trdi khdi Kontum ve Ddng Nam da tao sy cang gian xd tam (R Hall, 1997) hudng Tay Bae - Ddng Nam, tao cac... Bic Be° sang NamBesdr^ Bl''CiJu BcNaraC6n Honj Uong long Son BSMaLai-TTio Chu IT5v Nam Tuoi vacham Viel Nam) i Pliocen (N;l Vinh N: BienDong Miocen Nr Bien Dong Dong Tien Quang Dong Nam Con Minh... Tu>in tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co hdi mdi, thach thiic mdi" 91 Tiln hda kiln tao ciia cac be tram tich chira dau Kainozoi d Viet Nam cd the dugc chia ba giai doan: tien