Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam trudc them theky 21'
!.;< q -A HE THONG DOT GAY SAU VA PHAN V O N G CAU T R O C
THEO T A I L I E U DjA VAT LV LANH THO MIEN TRUNG VIET NAM
TS. Nguyen Tai Thinh ..,.,., ^. . , . ^: TS. Nguyen The Hung
^^" " " - ' • ' ' ''• . ' - ' ^ V ' ' ^ ^ ^ ' ^ ' ^ KS. Nguyen Trudng Luu Lien doan Vat ly • Dj'a chift
TOM TAT
Trong pham vi lanh tho mien Trung Viet Nam tir vl tuyen 12°3Q' den 11W, edng tac dia vat ly da dugc tien hanh nhieu nam, eae dang tai lieu rat phong phu. Cae tai tieu chinh gom: ban do trong luc fj? le 1:500.000, 1:100.000 ^
1:50.000, tai lieu bay do tir ty le 1:200.000 tai lieu bay do tir pho - gamma fj? le 1:50.000 ^ 1:25.000 Cac so lieu nay trudc day mdi dugc phan tieh theo tirng dang rieng biet eho eac viing dan le ma chua ed edng trinh nao xi? ly phan tieh tong hgp eac dang tai lieu vdi nhau va lien ket chung cho toan khu vue.
Trong nhUng nam gan day, cac tac gia da tien hanh xir ly, phan tich tong hgp cac so lieu tren vdi viec sir dung eac bd chuang trinh hien dai: COSCAD (CHLB Nga), trudng the (Cue Dia chat My) va E'.R.Mapper 5.2 (Oxtraylia) vdi mue dich nghien eUu cau triic, giai doan dia chat va khoanh viing then vgng khoang san theo to hgp eae tai lieu dia vat ly da cd.
Nhd ket qua tren, da xac dinh dugc cac he thong dirt gay chinh, phan loai va tinh toan cac yeu to san trang eiia chiing (hudng cam, gdc doc, chieu sau phat then va bien do dich chuyen, v.v...), dong thdi phan chia lanh tho nghien cUu thanh 9 ddi vdi 18 khoi cau true theo tai lieu dia vat ly. Cac ket qua nay se gdp phan nghien eUu sau han ve cau triic dia chat khu vue.
MCJOAU
Trong pham vi lanh thd mien Trung Viet Nam tff vT tuyen 12°30' den 17°00', cdng tac dja vat ly da dugc tien hanh nhieu nam, tai lieu rat phong phu. Cae sd lieu ehfnh gdm: tai lieu trpng luc t^ le 1 : 500.000, 1: 200.000 va 1:100.000 - 1: 50.000, tai lieu bay do tff t^ le 1: 200.000, tai lieu bay do tff phd - gamma ty le 1:50.000 -^ 1: 25.000. Tuy nhien, cac bao eao tdng ket mdi dffng d mffe khai thae mdt sd thdng tin ban dau dugc tien hanh rieng le, ehua cd dieu kien phan tfeh tdng hgp. Oay la vung cd eau true dja chat rat phffc tap, cd nhieu trien vpng ve khoang san chung, dac biet eac he thd'ng dfft g l y cd vai trd rat quan trpng trong viee hinh thanh cau true dja chat cua vung nghien cffu.
Ap dung cac tien bd khoa hpe ky thuat mdi ehung tdi da tien hanh xff ly phan tfeh cac tai lieu tren vdi viee sff dung cac bd chuang trinh hien dai: COSCAD (CHLB Nga), trudng the (Cue Oia chat Uy) va E.R.Mapper 5.2 (Oxtraylia) vao mue dfeh nghien cffu cau true, giai doan dja chat va khoanh vung trien vpng khoang san (theo td hgp eae tai lieu dia vat ly da cd).
Trong khudn khd bai bao nay, eac tac gia ehi gidi han mdt sd ket qua ve he thd'ng dfft gay sau va phan vung eau true lanh thd mien Trung Viet Nam theo tai lieu dja vat ly.
Qua ket qua nghien cffu - khao sat lanh thd mien Trung Viet Nam da xac dinh dugc eac he thdng dfft gay chfnh, phan loai va tfnh toan dffge eac yeu td san trang cua chung (hudng cam, gdc dde, chieu sau phat trien va bien dp dich ehuyen, v.v...), ddng thdi phan chia dugc lanh thd nghien cffu thanh 9 ddi vdi 18 khdi eau true theo tai lieu dja vat ly.
Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam tnfdc them theky 21'
CAC HE THONG DiS\ GhY THEO T A I LIEU OjA VAT L?
Theo ket qua phan tfeh, tdng hgp va giai doan eae tai lieu dja vat ly, vung nghien cffu da trai qua nhieu thdi ky hoat ddng kien tao vdi mffe dp khae nhau, tam ngffng nghi rdi tai hoat ddng manh me hon, nhat la trong eac giai doan sau. Tren binh dd eau true hien tai cd the xac lap dugc 4 he thdng dfft gay chfnh (Hinh 1). He thdng dfft g i y Tay Bac - Oong Nam, Odng Bae - Tay Nam, a kinh tuyen va a vT tuyen. Cac dfft gly sau dugc the hien ro tren cae ban do dang trj trudng trpng luc Ag^g, trudng tff AT^ (Hinh 2 va 3), va eae ban dd bien ddi cua chung, dac biet la eae ban dd phong bae thap qua eae dau hieu:
- La ranh gidi phan chia eae mien trudng cd dac tfnh khae nhau.
- He thdng eae dudng dang trj song song keo dai.
- He thd'ng chuoi cae dj thudng dja phuong phan bd keo dai theo mdt phuang.
Dudi day ehi md ta mdt sd dfft g l y sau ehfnh ed vai trd chij yeu phan chia eae ddi va khdi eau true.
1. He thong dut gay phirong lay Bic - Dong Nam
Day la he thdng dfft g l y phat trien manh me tren toan bd vung nghien cffu. Trong loat eac dfft gay nay, eae dfft gay ddng vai trd phan chia ddi va khdi cau true la dfft gly Ta Lao - Kham Offe, Sdng Ba 1, Sdng Ba 2, Huong Hoa - Hue, Oacglei - Tuy Phudc, Odng Xuan - Tuy An. Trong dd, eae dfft g l y Ta Lao - Kham Offe, Huong Hoa - Hue, Sdng Ba 2 cd cliieu sau phat trien theo ddi dugc tren 40km, cac dfft g i y Sdng Ba 1, KBang - Tuy Phudc, Odng Xuan - Tuy An, OacRong - Hdi An, v.v... chieu sau theo ddi dugc 30 - 40km.
• Dijft gay Song Ba 2: La dfft gay sau keo dai tff Nam Sa Thay den Cung Son. Tai lieu dja vat ly da khang djnh va lam ehfnh xae them vj tri eua dfft gay nay tren ban do dja chat hien ed. Ket qua phan tfeh djnh lugng tai lieu trpng luc va tff eho thay dfft g l y nay cam thoai (40°- 55°) ve phia Oong Bac, bien dp djch ehuyen dffng 2km.
• Dut gay Song Ba 1: La dfft gay sau keo dai tff Oactd xudng Tuy Hoa. Ket qua phan tfeh djnh lugng tai lieu trpng luc va tff cho thay dfft g l y nay cam thoai (50°- 65°) ve phia Tay Nam, bien dp djch ehuyen dffng 1,7 km. j ^ ;^,,:
Offt gay Sdng Ba 1 va 2 the hien rd tren bffc tranh trudng tff, trpng luc va cae bie'n ddi eua chung.
Tren ban dd dang trj phdng Ipe nang lugng bae 1 va nang trudng d dp cao khac nhau, hai dfft g l y nay tao nen su bie'n ddi dot ngdt, cd he thdng dudng dang trj song song phat trien dpe theo hudng cua dfft gay. Cd le hai dfft g l y nay tao nen dja hao Sdng Ba.
• Diit gay Ta Lao - Kham Diirc: Keo dai tff Ta Lao qua Kham Offe de'n Ba To. Ket qua tfnh djnh lugng theo tai lieu trpng luc, dfft giy cam 50° - 75° ve phfa Tay Nam. 6 phfa Tay Bac dfft g i y nay ed ve nhu cam dffng hon va thoai hon ve phfa Odng Nam. . ^ ...,. , •
• Out gay HUYig Hoa - Hue: Offt gay nay dugc the hien rat rd tren ban dd dang trj Bughe, ban dd dang trj trudng tff va eae bien ddi cua chung. Tai noi dfft g l y di qua gia trj trudng trpng luc Bughe bien ddi dot ngpt tff duong sang am, xu the eac dudng dang trj song song dpe theo dfft giy. Ket qua tfnh djnh lugng theo tai lieu trpng luc, dfft giy hoat ddng d dp sau khoang 25km, cam 70° ve phfa Odng Bac.
Tren day la bdn dfft g l y chfnh trong he thd'ng dfft gay phuang Tay Bac - Odng Nam. Ngoai ra edn nhieu dfft g l y khae ed the xem chung la nhffng dfft g l y sau (nhung cudng dp va khong gian hoat ddng kem hon): dfft gly KBang - Tuy Phudc, Odng Xuan - Tuy An, v.v...
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Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam tnfdc them theky2i'
Hinh 1. So dd phan vung eau true theo tai lieu dja vat ly vung mien Trung Viet Nam
• - ; • ,: t ^ l e l : 2.000.000
Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam trwdc them theky 21'
Hinh 2. Ban dd dang tri trudng tff ATa vung mien Trung Viet Nam ty le 1 : 2.000.000
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H6I nghi KHCN 2000 "Nganh Dau khi Viet Nam tnfdc them theky 21'
Hinh 3. Ban dd dang trj trudng trpng luc Bughe vung mien Trung Vidt Nam ty le 1 : 2.000.000
CHI DAN
- 1 ^
hwlao'
Hoi nghi KHCN 2000 "Nganh Dau khi Viet Nam trifdc them theky 21'
2. He thdng dut gly Ddng B k - Tay Nam
He thdng dfft gly nay phat trien chu yeu d phfa Nam mien Trung tff 12°40' de'n 15°20'. Oang quan tam nhat la cae dfft giy: dfft gly Ba To - Gia Vue, Tuy Hoa - Buon Ma Thupt, Que San - Buon Hd, Vinh Thanh - Hoai Nhan, Vinh An - Cat Tien, v.v... Trong dd, dfft g i y Ba To - Gia Vue va Tuy Hoa - Buon Ma Thupt ed dp sau phat trien Idn. Theo tai lieu tfnh toan, dp sau theo doi dugc cua cac dfft gay nay > 40km.
• Dut gay Ba TO - Gia VUc: Offt gay keo dai tff phfa Nam Kon Tum qua Ba To ra bd bien. Nd dugc the hien ro tren tai lieu tff va trpng luc, tai dd trudng trpng luc va trudng tff thay ddi dot ngpt ve gia trj cung nhu phuang cau true trudng. Ket qua tfnh djnh lugng eho thay dfft gay cam 60°- 65° ve phia Tay Bac.
• Duft gay Tuy Hoa • Buon Ma Thudt: Nam d phfa Nam vung nghien cffu, tai dd gia trj trudng trpng luc chuyen dan tff am sang duong (ve phfa Nam), dj thudng trudng tff thay ddi tff mien phffc tap sang mien binh dn. Dac biet tai lieu nang trudng trpng luc va tff theo cac dp cao khac nhau phan anh kha rd. Ket qua tinh djnh lugng theo tai lieu tff cho thay dfft gay cam thoai 50°- 65°ve phfa Tay Bae.
3. He thdng dut gay a vT tuyen
He thdng dfft gay a vl tuyen quan sat rd chu yeu khu vue phfa Bae vung (tff 15°00' den 17°00'), dudi 15°00', he thdng dfft g i y nay ehi quan sat dugc cac doan khong lien tue, cd le chung bj cac he thdng dfft gly khae phan eat va lam djch chuyen.
Trong he thdng dfft gay nay, dang quan tam la cac dfft g i y sau: dfft gay song Vu Gia, dut g l y Tam Ky - Phudc Son, Huong Hoa - Oa Ning va he thdng dfft gay Tra Mi - Bong San. Trong cae dfft g i y tren, dfft giy song Vu Gia va dfft gay Tam Ky - Phudc Son theo ddi dugc dp sau > 40km.
• Diit gay Tra Mi - Bong Sdn: Oay la he thdng dfft gly song song theo phuang a vT tuyen bao gdm cac dfft gly ehfnh: Nui Thanh - Kham Offe, Tra Mi - Tra Bong va Tra Mi - Bong Son. Trong dd, cd le dfft gay Tra Mi - Bong Son la dfft gay phat trien sau hon ca. Ket qua tinh djnh lugng theo tai lieu trpng luc va tff cho thay dfft giy hoat dpng d dp sau vai ehuc km, cam 70°-80°ve phfa Bac.
• Dut gay sdng Vu Gia: Oay la dfft giy sau phat trien manh me. Cac dau hieu the hien rd tren ban dd dang trj trudng tff va trpng luc, cac bien ddi Trend, dae biet tren cac ban dd Ipe nang lugng va nang trudng, Ket qua tfnh djnh lugng theo tai lieu trpng luc va tff eho thay dfft g i y cam 60°- 90° ve phfa Bae.
4. He thdng diit gly a kinh tuyen
Oay la he thdng dfft giy hoat ddng d thdi ky muon nhat so vdi cae he thdng dfft gay khae trong vung.
Cae dfft gay nay theo doi dugc lien tue tren eac ban do trudng dja vat ly va ft bj eac dfft gay theo cae he thdng khac lam djch chuyen. Trong he thdng dfft gay a kinh tuyen, dang luu y la cae dfft giy: KonPlong - AYun Pa, MadRac - An Khe, v.v... Cac dfft g i y nay deu theo ddi dugc d dp sau Idn. Ngoai cac dfft g i y ehfnh ke tren, theo tai lieu dja vat ly cung da vach dugc hang loat cac dfft gly khac (dfft g i y cap 1, 2 va 3) theo eae hudng khac nhau. Chung ehi la eac dfft g l y noi ddi hoac keo theo khong lam anh hudng den eau true dja chat cua vung. Cudng dp va khdng gian hoat ddng kem hon cac dfft giy ke tren.
CAU T R U C OIA CHAT THEO T A I LIEU OjA VAT LY
Tdng hgp, phan tfeh dae diem phan bd cua cac trudng dja vat ly (trudng tff, trpng luc, phd gamma, v.v...) eho thay eau true lanh thd mien Trung cd dang nhu khdi tang, cac khdi tang nay deu dugc gidi han bdi cae dfft g l y sau.
Dua theo dac diem trudng dja vat ly ed the chia dien tfeh mien Trung thanh 9 ddi cau true vdi 18 khdi.
Cae khdi eau true dugc the hien bdi su khae biet ro rang ve dac diem trudng vat ly d dudi sau: truang phdng
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Hoi nghi KHCN 2000 "Nganh Dau khi Viet Nam tnfdc them theky 21'
bac thap va nang trudng d dp cao Idn, tuang ffng phan anh cac thanh tao khac nhau cua mdng. Gidi han cua cac ddi cau true la cac dfft g i y sau. Mdi ddi cau true lai dugc chia thanh cac khdi cau true, cac khdi nay phan anh su khac biet cua trudng dia vat ly d mffe nong hon, phan anh cac thanh tao dia chat phan tren mdng.
1. Ddi nang Sdng Ba i
Odi nang Song Ba cd ranh gidi phia Bac la dfft g i y Ba To - Gia Vue, phia Tay va Tay Nam la dut giy sau Song Ba 2 va phfa Nam bj khdng che bdi dfft gay sau Tuy Hoa - Buon Ma Thupt. Tai lieu trpng luc the hien su nang tuang ddi cua ddi cau true nay, bdi gia trj am khong Idn d phfa Tay (-30mgl), tang dan va dat cue dai a phfa Oong (+15mgl). Trudng tu ATg chu yeu la am (-200 -f- 50nT), phan Trung tam va phia Nam xuat hien nhieu di thudng don phffc tap. Mdng cua ddi nay phan anh chu yeu la cac thanh tao bien chat cd Arkeozoi. Theo tai lieu dia vat ly cd the chia ddi nang Sdng Ba thanh 6 khdi eau true.
• Khdi Ba Td: Khdi nam phia Bac ddi, dac trung trudng tff ft bien ddi, cudng dp dao ddng tff -100 -f 25nT, trudng trpng luc thay ddi tff -10 ^ 5mgl. Cac thanh tao dia chat chu yeu la eae da ket tinh tudi Arkeozoi vdi su cd mat he tang Xa Lam Cd (AR.J, Oae Ld (AR^,), eac thanh tao macma quan sat dugc la cac thanh tao phffc he Ben Giang - Que San, granit phffc he Oeo Ca va phffc he Hai Van.
• Khdi Phu My: Nam d Trung tam ddi nang Sdng Ba, gidi han bdi dfft gay Oacglei - Tuy Phudc phia Tay, dfft g l y Vinh Thanh - Hoai Nhan phia Bac va dfft gay Tuy An - Phu Cat phfa Odng Nam. Oae diem trudng trpng luc am kha Idn, d phfa Tay (-30mgl) tang dan ve phfa Odng (+2mgl). Trudng tff thap kha binh dn vdi cudng dp tff -100 ^ 50nT. Thanh tao dja chat ehu yeu la cac dat da tudi Arkeozoi, tao nen nep Idi Kannak (he tang Kon Cot, Xa Lam Cd, Oae Ld, v.v...). Hoat dpng macma xam nhap phat trien d Nam, Tay Nam va phia Bac, gdm granitoit phffc he Ben Giang - Que San va granit phffc he Oeo Ca.
• Khdi An Khe: Khdi cd dang keo dai Tay Bac - Odng Nam, bj khdng che bdi dfft g l y KBang - Tuy Phudc phfa Odng, dfft gly Kon Plong - AYun Pa phfa Tay dfft gay Sdng Ba phfa Tay Nam va dfft gay Tuy An - Phu Cat phfa Odng Nam. Trudng trpng luc am binh on so vdi eac khdi lan can (-22 H- -30mgl).
Trudng tff am it bien ddi (-100 ^ 25nT) xuat hien nhieu dj thudng dja phuang bien dp nhd. Cac thanh tao dja chat chu yeu la thanh tao Arkeozoi vdi su phat trien manh cua macma xam nhap phffc he Ben Giang - Que San, phffc he Van Canh va da phun trao he tang Mang Yang.
• Khdi Kon Cho Ro: Khdi nay chiem giu vj tri phfa Nam va Tay Nam cua ddi. Oao diem trudng trpng luc am (-14 ^ -2mgl) vdi nhieu dj thudng nhd sap xep theo hudng Tay Bac - Odng Nam. Trudng tff am bien ddi phffc tap vdi cudng dp dao ddng tff -200 -^ OnT. Cac thanh tao da cd Arkeozoi xuat hien dang sdt, maema xam nhap phffc he Ben Giang - Que Son, phffc he Van Canh, phffc he Oeo Ca, ria Odng Nam khdi phat trien da phun trao he tang Dan Duang, Nha Trang. .
• Khdi Ky Lo: Nam kep giua hai dfft giy Odng Xuan - Tuy An phfa Odng Bac va dfft g i y Sdng Ba phfa Nam. Trudng trpng luc Bughe gdm hai phan am (-14mgl) va duang (10mgi) vdi hudng ehu dao Tay Bac - Odng Nam. Trudng tff am bien ddi tff -200 ^ -lOOnT, ed nhieu di thudng nhd bien dp thap. Trong ndi khdi khdng thay xuat hien da cd Arkeozoi, hoat ddng macma kha manh me, xuat hien cac thanh tao phffc he Ojnh Quan, phffc he Van Canh ,va cac da phun trao he tang Oon Duong, Nha Trang va Oeo Bao Lpc.
• Khdi Sdng Cau: Nam sat bd bien kep giffa khdi Ky Lp, An Khe va Phu My. Trudng trpng luc am phia , Tay (-22mgl) tang dan va duang d phia Oong (+6mgl). Trudng tff thap (-100 ^ 25nT), bien ddi phffc tap, xuat hien nhieu di thudng don. Hoat ddng macma kha manh me, gdm eac thanh tao phffc he Ben Giang - Que San, Oinh Quan, Van Canh va Oeo Ca.
Hoi nghj KHCN 2000 " Nganh Dau khi Viet Nam tnfdc them theky 21'
2. DdiKrong Nang
Odi dugc gidi han bdi dfft gly sau Sdng Ba phfa Bae, dfft gay Tuy Hoa - Budn Ma Thupt phfa Nam.
Phan Idn dien tieh ehua ed sd lieu do chi tiet trpng luc [^ le Idn, phan ria khdi tiep giap vdi mien trpng luc am.
Trudng tff am kha binh dn dao ddng tff -100 -r 25nT. Tham gia cau true ddi gdm eae thanh tao Paleozoi va Mesozoi he tang Ca Lui, Oon Duong va deo Bao Lde. Hoat dpng macma xam nhap d thdi ky Jura - Creta xuat lp eac khdi macma phffc he Ojnh Quan va Oeo Ca.
3. Ddi Madrac - Tuy Hoa
Odi chiem phan phfa Nam eua dfft g l y Tuy Hoa - Budn Ma Thupt, vdi phuang keo dai a vTtuyen. Oae diem trudng trpng luc am (-30mgl) d phfa Tay tang dan den duang (+16mgl) d phfa Oong. Trudng tff gdm hai phan am, duong trung vdi hai phan am, duong cua trudng trpng luc, gia trj thay ddi tff -200 H- 50nT.
Thanh tao dja chat gdm cae da he tang Kham Offe va cae da tram tfeh luc nguyen he tang Oray Linh, Easup. Hoat dpng macma phat trien cae thanh tao phffc he Chu Lai, Ojnh Quan, Oeo Ca, va cae thanh tao da phun trao he tang deo Bao Lpc, Oon Duong, Nha Trang.
4. Ddi Ngpe Linh - Kon Tum
Odi Ngpe Linh - Kon Tum giap vdi ddi nang Song Ba qua dfft gay sau Ba To - Gia Vue d phfa Nam, Odng Nam giap vdi ddi Sa Thay qua dfft g l y Kon Tum - Oae Ha, phfa Bae giap ddi Offe Phu - Kham Offe qua dfft g l y Tra Mi - Bdng Son. Theo tai lieu dja vat ly ddi dudc chia thanh hai khdi eau true:
• Khdi Mo Dufc: Khdi Md Offe nam phfa Odng Bac ddi ngan each vdi khdi Ngpe Linh bdi dfft g l y Ta Lao - Kham Offe. Trudng trpng luc Bughe tang dan tff Tay Nam (-40mgl) den Odng Bac (+6mgl). Trudng tff am ft bien ddi vdi cudng dp tff -100 -^ -25nT. Cae thanh tao dja chat ehu yeu gdm cac da bien chat cd tudi Proterozoi he tang Tac Pd va Sdng Re. Cac da macma xam nhap gdm cac thanh tao phffc he Chu Lai, Cha Van va Hai Van.
• Khdi Ngoc Linh: Phan edn lai phfa Tay Nam la dien tfeh khdi Ngoc Linh. Oae diem trudng trpng luc am Idn (-80mgl) vdi nhieu dj thudng dja phuang khep kfn dang dang thude. Trudng tff bien ddi manh, cudng dp thay ddi tff -300 ^ 25nT, vdi nhieu dj thudng don dang thude. Cac thanh tao dja chat chu yeu gdm eae da bien chat cd tudi Proterozoi he tang Tac Pd va Song Re. Hoat ddng macma kha manh me, gdm eac thanh tao macma tudi tff Paleozoi den Kainozoi, nhu eac da phffc he Ben Giang - Que San, Dien Binh, Oai Lpc, Van Canh va Ba Na.
5. Ddi Sa Thay
Odi Sa Thay nam d Tay Nam vung nghien cffu, tiep giap vdi ddi Ngpe Linh - Kon Tum bdi dfft g i y Kon Tum - Oae Ha, phfa Odng Nam la dfft g i y Song Ba'2. Oae diem trudng trpng luc am (-46 ^ -22mgl), trudng tff thap bien ddi phffc tap, tao thanh ehudi cac dj thudng dja phuang phan bd theo hudng keo dai cua ddi. Cae thanh tao dja chat chu yeu gdm cac thanh tao eua he tang Kham Offe, macma xam nhap chu yeu la eae thanh tao phffc he Ben Giang - Que Son va Hai van.
6. Ddi QClc Phu - Kham Dufc
Odi giap ndi vdi ddi Ngpe Linh - Kon Tum qua dfft gay Tra Mi - Bong Son phfa Nam, phia Bac la dfft g l y sdng Vu Gia. Theo tai lieu dja vat ly ed the chia ddi thanh ba khdi cau true:
• Khdi Nui Thanh - Kham Dde. Khdi nam d phfa Nam ddi, phia Bac bi chan bdi dfft g l y Tam Ky - Phudc Son. Trudng trpng luc ed cau true phffc tap, tao bdi nhieu di thudng dia phuang vdi phuang chu dao a vl tuyen, gia trj tang dan tU -60mgl phfa Tay den +15mgl phfa Odng. Trudng tff am kha binh dn (-100 - - 25nT). Cac thanh tao dja chat ehu yeu gdm cac da he tang Kham Offe, hoat ddng maema kha manh
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Hoi nghi KHCN 2000 "Nganh Dau khi Viet Nam tnfdc them theky 21'
me gdm mdt loat cae thanh tao phffc he Tra Bdng, Oai Lde, Ben Giang - Que Son, Hai Van va Ba Na.
• Khdi Hiep Dufc: Khdi nam d phan ria Oong ddi Offe Phu - Kham Offe va tiep giap vdi bien Oong. Dae diem trudng trpng luc duang (+15mgl) va gan trung dj thudng tff ldn keo dai khoang 40km theo phuong a vT tuyen. Khdi bj phu day bdi tram tfeh Neogen - Oe Tff dudi nd la cac thanh tao he tang Nui Vu va AVuong. Cac thanh tao maema xam nhap gdm eac da phffc he Ben Giang - Que Son, Hai Van, Cha VanvaBaNa.
. Khdi Ndng Sdn: Khdi Ndng Son nam d phfa Bae ddi, tiep giap vdi ddi Oai Lpc qua dfft gay sdng Vu Gia. Khdi trung vdi mot dj thudng trpng luc duong tuang ddi, kfch thude kha Idn keo dai phuong a vT tuyen, gia trj thay ddi tU -20^ 25mgl, day cung la mot dj thudng tU am khep kin phan ria ed cudng dp -
lOOnT giam dan vao Trung tam (-300nT). Cae thanh tao dja chat chu yeu gdm eac da he tang Kham Offe, AVuong, Song Bung va Ndng Son. Cac thanh tao maema xam nhap gdm eac da phffc he Cha Van va Hai Van. ,,
7. Odi Dai Loe
Odi Oai Lde duoc gidi han bdi dfft gly sdng Vu Gia d phfa Nam, dfft gly Huong Hoa - Hue d phia Bac va dfft giy Ta Lao -Kham Offe d phfa Tay. Theo tai lieu dja vat ly ddi dugc chia thanh hai khdi cau true:
• Khdi Ba Na • Hoi An: Khdi ed dang keo dai theo phuang a vT tuyen, nam d nffa phan phfa Nam ddi.
Trudng trong luc Bughe am (-20 ^ -6mgl), trudng tff kha binh dn gia trj thay ddi tff -100 ^ -50nT. Cac thanh tao'dia chat ehu yeu gdm cac thanh tao he tang AVuong, Long Oai va Tan Lam. Hoat ddng macma kha manh me gdm cae thanh tao phffc he Ben Giang - Que Son, Oai Lde, Cha Van, Hai Van va
! BaNa. .,,..,.. . ,,,
. Khdi ALUdi - Nam Odng: Khdi ed dang keo dai theo phuong Tay Bac - Odng Nam nam d phia Bae ddi.
Oae diem trudng trpng luc chu yeu la am (-40 ^ -6mgl) eac dudng dang trj song song keo dai theo phuang Tay Bac - Odng Nam. Trudng tff am kha binh dn gia trj thay ddi tff -100 ^ -25nT. Cae thanh tao dia chat ehu yeu gdm cac thanh tao he tang Long Oai, Tan Lam, maema xam nhap chij yeu eae da phffc he he Ben Giang - Que San, Hai Van va Ba Na.
8. Odi HUdng Hoa - Dac Prinh
Odi Huong Hoa - Oae Prinh nam d Tay Bae vung nghien cffu, dugc phan each vgi cac ddi khac bdi dfft giy Huong Hoa - Ta Lao - Kham Offe. Dac diem trudng trpng luc am (trung binh -SOmgl), trudng tff kha binh dn, gia trj thay ddi tff -50 ^ -lOOnT. Cac thanh tao dia chat chu yeu la cae da he tang AVuong, ALin, Sdng Bung va Hffu Nien, cac the xam nhap xuyen cat trong khdi ehu yeu la da phffc he he Ben Giang - Que Son, Hai Van va Cha Van.
9. Odi Hue
Odi nam d phfa Bac vung nghien cffu, dugc phan each vdi ddi Oai Lpc bdi dfft gly Huong Hoa - Hue.
Oae diem trudng trong luc la eae dudng dang tri phat trien song song, keo dai theo phuong Tay Bae - Odng Nam gdm hai phan am'(-SOmgl) d phfa Tay va duong (+15mgl) d phfa Oong. Trudng tU kha binh on, gia tn dao ddng trong khoang -50 ^ 25nT. Cae thanh tao dja chat ehu yeu la tram tfeh Neogen - Oe Tff va cac thanh 'tao he tang Tan Lam, Long Oai, va Cd Bai. Thanh tao macma chu yeu la thanh tao phffc he Ben Giang - Que Son.
KET LUAN
Theo tai lieu dja vat ly, eau true dja chat lanh thd mien Trung Viet Nam mang dang khdi tang rd ret.
Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam trifdc them theky 21'
Cac hoat ddng kien tao trong vung da hinh thanh nen cac ddi eau true Idn ban dau, sau dd ehung tiep tue bj pha vd, phan cat bdi cac pha hu^ dfft gay trong giai doan sau. Cae dfft gly ldn noi bi dap vd manh la kenh dan eho macma xam nhap xuyen tff dudi sau len.
Cac tac gia hy vpng rang nhffng ke't qua budc dau tren day se la nhffng thong tin gdp phan vao viec nghien cffu sau hon ve nhffng dae diem cau true dja chat va dieu kien sinh khoang eua khu vue nay.
TAI LIEU THAM KHAO
1. Pham Khoan. The faults and intruction of Vietnam's territory found according to the interpretation of geophysical data. Journal of Geology, B/5-6, p. 395 - 405,1995, Hanoi.
2. Tran Offe Luang, Nguyen Xuan Bao va n.n.k. Ban do dia chat Viet Nam t^ le 1:500.000. TCMOC, 1982, HaNpL
3. Nguyen Xuan Son. Giai doan cau tmc dia chat mien Nam Viet Nam dua tren ban do tir hang khdng tf le 1:200.000. TT Luan an PTS OL- OC. Thff vien Qudc gia, 1996, Ha Ndi.
4. Nguyen Tai Thinh, Nguyen Duy Tieu, Le Vinh Hdng. Mot so ket qua do ve trong luc fj? le Idn (1:50.000) d V/ef Warn. TC Oja chat 210 - 211, 9 - 22,1992, Ha Ndi.
5. Nguyin Tai Thinh, Nguyen Duy Tieu. Dirt gay sau va cau trite dia chat vung Hue - Huang Hoa theo tai lieu dia vat ly. Bao eao Hdi thao va Trien lam qudc te ve dja vat ly, 89 - 91,1992, Ha Ndi.
6. Tran Van Trj, Nguyen Offe Uy, Hoang Hffu Qui, Lam Thanh. Kien tao Tay Nguyen va cac vung phu can.
TTBC Hdi nghj KHKT DCVN lan 2,1970 -1984,1984, Ha NdL
7. Cao Oinh Trieu, Nguyin Danh Scan. He thong dirt giy chinh lanh thoVietNam tren casdphan tich ket hgp tai lieu trong luc, tir va anh ve tinh. TCOC 247, p. 7 - 8,1998, Ha Ndi.