PETROVIETNAM Dgc diem thdnh phan vdt chdt cdc dd magma Mesozoi muon Kainozoi som vung Binh Thudn (Dong Nam Dd Lgt) vd khodng sdn lien quan TS Nguyin Trung Chi Viin Ddu khf Viit Nam TS Ngd Vin Minh Tru[.]
PETROVIETNAM Dgc diem thdnh phan vdt chdt cdc dd magma Mesozoi muon - Kainozoi som vung Binh Thudn (Dong Nam Dd Lgt) vd khodng sdn lien quan TS Nguyin Trung Chi Viin Ddu khf Viit Nam TS Ngd Vin Minh Trung tdm Kiem dinh vd Cdng nghS Dia Tren c , , < 0,3 C.-iO Hmi} Hf i; dd iva.O-K,0-CaO l%wt)phdn chia loai sodIc, potdsic •o irt, 19531 tuang ling vdi loot sodic Id trudng granite k/.'( Ji I • 1,1) va thap canxi (C* < 0,3) Vdi nhdng dac trung dia hda nhuvay, theo White va Chappell (1974), Whaien {1987), cic da granitoid Deo Ci vung Ga Lang, Binh Thuin thupc kieu S-granite Hinh Bieu phdn b6 cdc nguyin td khdng tUang hap chudn hda vdi N-MORB cua cdc dd phun trdo hi tdng Nha Trang - phu hi Cic nguyen td khdng tUPng hop eua chung chuan tdng trin (Knt,) (theo Condie, 1989) Gid tri N-MORB (theo Wood, hda vdi bazan sdng nui dai dUong kieu binh thudng 1979); gid tn trung binh kieu I (theo Whaien, 1987) {N-MORB} va granite song nui dai duong (ORG) eho thay cic granitoid Deo Ci gidng vdi mau chuan granite kieu S va thupc kieu granite ddng va cham (syn-COLG), phu kieu va cham gida cung d i o vdi luc dja - ma dien hinh la d vung vjnh Oman va Bolivia (Pearce, 1984) Tren cac bieu tii Hinh 1-14, nhdm tac g i i nhin thay cac da granitoid Deo Ci cung loat v i cung kieu magma vdi phun t r i o phu he tang tren he tang Nha Trang, ve quan he khdng gian ehung xuyen cat cac da phun t r i o acid vdi mdc tudi {K^) theo t i l lieu hien ThUc te, cic t i i lieu tren eho thay chung cung ngudn gdc thinh tao eung mdt ehe kien tao (syn-COLG) Ndi each khac, chiing la mpt to hpp Hinh 10 Biiu phdn bo cdc nguyin to khdng tUang hap chudnnui Ida-pluton rat die trUng cho sUtien hda cua mpt ddi va cham kieu ria luc dia tich cue hda vdi granite ORG cOa cdc dd phun trdo hi tdng Nha Trang - phu he tdng tren (Knt^ Gid tri granite cung ndi Ida kieu Chi H vd granite ddng va chgm kieu Oman (theo Pearce 1984} Hinh 12 Bliu phdn bddid hda ede nguyin td khdng tuang hap Hinh 11 Biiu phdn bd cdc nguyin to chudn hda theo chudn hda vdi granite (ORG) cOa cdc dd granitoid phUc he Deo N-MORB cOa cdc dd granitoid phdc hi Dio Cd (theo Condie 1989) Gid tri N-MORB (theo Wood 1979); gid tri trung binh kieu S (theoGid tri granite cung nui Ida kieu Chi Li vd granite dong va cham he Oman (theo Pearce, 1984) Whaien 19B7) sC DAU KHi Theo nhdng t i i li^u nghiSn cdu cic 6it magma d khu vUc "dj thudng td Ga Ling", Binh Thuin, chung tdi c6 nhdng nh§n djnh nhdsau: Cic d i phun t r i o andesit, andesitodaeit, dacit thuOc phM h0 t i n g dddi h^ t i n g Nha Trang ed le dong magma vdi pha x i m n h i p d i u tifin cOa granitoid Dio Ci t^o t h i n h mdt td hpp nui Ida - pluton thudc loat ki^m vdi, kl^u l-granite, vdi tinh sinh khoing die trUng l i ki^u Cu-porphyr ehda molibdenit v i di eung vdi khoing h6a v i n g nhi^t djeh giai doan mudn (S.W.Piteher, 1993) Cic d i phun t r i o acid thudc phu h& t i n g trgn h^ ting Hinh IJ Bliu dd Nb-Y, phdn chia cdc kliu kiin tgo granite: Nha Trang c6 le ddng magma vdi pha xam nhip thiJ cua syn-COLG - ddng va chgm VAC - granite cung nOiliia, WPG - granite granitoid D^o Ci tao nSn mdt td hpp niii Ida - pluton thu6c mdng, ORG - granite (theo Pearce, 1984) cho cdc dd granitoid vdphun trdo vung Ga Ldng; kyhiiu nhu Hinh loat kilm - vdi, ki^u S-granite q u i bao hda nhdm mang bin chit cua Idp vd vdi sinh khoing dae trung l i Sn, W v i kim loai m i u dUPe t i i ddng vi&n td cic t r i m tich c6 v6 Nhu viy, eie t i l lilu thach dja hda eho thay phun trio he t i n g Nha Trang ddng magma vdi granitoid Deo Ci tao n^n mdt td hpp nui Ida - pluton eua eung magma, thudc loat kiem - vdi v i mang tinh trdn lan magma gida kieu I vi S duoc hinh thinh che dp ria luc dja tich cue kieu AndP, xiy v i o giai doan gida cCia qua trinh tien hda magma 6i6 D i Lat (tudi K^) m i glal doan d i u {tudi J^ - K,) duoc dac trUng bing td hpp mil Ida - pluton loat kiem - vdi, kieu l-granite {he t i n g Deo Bio Ldc ciing vdi cic granitoid Dinh Quan) va Hinh 14 Bliu Rb-(Y + Nb), phdn chia cdc kieu kien tgo granite giai doan cudi (E) duoc die trUng bdi to hop niii Ida - pluton cho cdc dd magmd vung Ga Ldng; ky hiiu nhu Hinh loat kiem - vdi kieu S-granite (he tang £Wn Ducmg cung vdi Mot vai van de ban luan Td nhdng nghien edu ve phan vat chat v i thaeh cic d i granitoid AncroetviCaNi) [12,13] Mot so gdi y cho viec t i m kiem khoang s i n luan ngudn gdc cua cac d i xam n h i p va phun trao khu Viec xac n h i n sU cd mat ciia che dp ria lue dja tich vue "dj thudng t d Ga Ling", Binh Thuin dat mdt sd van cue kieu Ando v i o thdi ky Jura mudn - Creta sdm (J,- de can phii ban luan: l i viec ghep ndi cac phun t r i o ed K,), ti^p dien qua thdi ky Creta mudn (K^) va ket thiie nguon gdc khie (khdng cung day p h i n dj magma) vao Paleogen {E) da dUOc Nguyen Xuan Tung, Tran Van vao cung mdt he tang cd hop ly hay khdng? Trong pham Tn (1992) neu l i n dau tien dViet Nam [10] {d phan VI ddi Da Lat, nhdng tao phun trao duoc phin chia Nam Trung Bd v i Tiy Nam Bd) Cic dOn vj eau true kien trudc day nhU he tang Deo Bio Ldc {Jj - K, dbl), he tang tao - magma lien quan vdi che dp cung duoc xac lap Don Duong (K^ dd), h^ tang Nha Trang {K-E nt) [2] hien nhu cic t h i n h tao pluton - nOi ICfa, ddi tai c i i trude rift tai cd tdn tai hoac tUPng dong vdi phun t r i o he tang Nha Cic t i i lieu nghien cdu thach iuan vung Ga Lang eung Trang mdi dupe phin ehia nhdm td Phan Thiet hay gdp phan minh ehdng th^m ve su ton tai ciia cic don khdng? [7] Theo chung tdi, viec djnh duoc eic "nhip" vj cau true c h i dd k i l n tao dd Vung Binh Thuin magma ddi D i Lat trudc d i y la hoan t o i n dung d i n ndi rieng v i ddi D i Lat ndi chung n i m trpn cau ve quan h^ dja chat theo khdng gian v i thdi gian cung tnic cung nui Ida Ngoai dac d i l m thaeh luan cua td hpp nhu ve t h i n h p h i n v i t ehat eua chiing vdi nhdng sd lieu c i c d i granitoid v i andesit-ryodacit neu tren edn cd nfiot phan tich d thdi ky dd cung vdi nhQng quan diem cu ve dau hieu quan trpng de nhan b i l t cung niii Ida l i dj h^ magma v i sinh khoing Tuy nhien, dieu dd gay thudng trpng luc t h i p v i cd gradien dia nhiet rat cao da su"khd hieu" luin g i i i mdi lien quan cua magma va dupc cic t i i lieu dja v i t ly x i c n h i n [4] sinh khoang ddi D i Lat r 18 DAU ml-sd 11/2012 PETROVIETNAM Bdng Kit qud phdn tich hda hgc cdc nguyen td chinh vd nguyin td vit cdc dd magma hi tdng Nha Trang, phu hi tdng dudi vd granitoid Dio Cd H e t j n g Nha Trang, phu he tang dU61 C.650 SiOj P.27238 ' PS740I^ 60,960 64,900 TiOi 0,590 AI^O, 17,430' 16,940 Fe^dj 0,510! P.710 71,720 P.17698 Granitoid Dto C i Oman 72,100 72,300 , 0,210; 0,110 13,790 14,300 72,300 0,320 0,260 14,620 14,110 P.23404 70,760 0,380 ! 14,730 1.224/1 P.28566 P.2860 P.28597 P.285a5 TB kiju S 70,270' 75,960 76,100 76,860 77,640 77,660 0,160 0,110 0,130 0,140 0,130 0,480 12,920 13,400 12,790 12,930 12,790 14,100 1,450 0,320 1,460 0,490 0,990 j 2,330 2,610 1,020 1,050 0,950 0,600 0,720 0,560 FeO 5,010 4,870 4,120 2.490 1,500 0,000 0,360 0,420 0,270 ' 0,330 0,240 0,180 2,870 MnO 0,170 0.140 0,160 0,130 0,070 0,100 0,060 0,040 0,030 , 0,030 0,030 0,020 0,060 MgO 1.400 1.030 0,370 ! 0,280' 0,890 2,190 0,610 0,000 0,000 ' 0,180 0,050 0,090 1,420 CaO 4,560 3,000 0,780 0,910 1,110 2,630 0,200 0,060 0.000 0,060 0,130 0,000 2,030 NajO 4,240 3,340 3,370 3,970 4,350 2,700 3,620 3,340 3,040 3,590 3,250 3,520 K2O 2,600 3,270 3,020 4.570 2,200 3.380 4.790 4,230 3.840 4,160 3,650 4,190 3,960 PjOs 0.150 0.110 0,000 0,020 0,040 Mkn 0,500 0,670 0,000 0,000 0.790 : H2O£ 0,000 0,020 0.090 0,050 0,060 99,060 99,120 99,090 99,420 99,240 0.150 2,410 J 0.060 0.010 0,010, 0,010 0,010 0,010 0,1501 1.160 0,950 1,460 0,440 0,960 0,600 0,000: 0.24O 0.080 0,280 0,030 0,140 0.140 100,150 99,580 99,190 99,590 99,560 99,770 100,050 0,000' 98,110 L09T 1,349 1,426 1,696 1,973 1.506 Logo 0,146 0,300 0,153 0,399 ; 0.166 Na/K 1,630 1,020 1,020 0,870 1.980 5m 6,100 7,600 5,200 7,500 7,600 13,700 7,600 14.200 7,0201 Ce 147,000 57,000 73,200 130.000 63,000 63,000 62,000 ' 102,000 64,000^ f \ 5,300 1,640 3,100 5.300 Zr 10,000 10,000 108,000 410,000 200,000 100,000 180,000 160,000 165,0001 Rb 104,000 167,000 76,000 175.000 248,000 324,000 234,000 202,000 217,000 5,900 6,000 5,800 6.200 83,000 201,000 119,200' 65,000 82,000 59.000 ' 51,000 468,000' 71.000 10,000 10,000 10.000 42,000 120,000 0,680 2,410 1,600 0,6401 46,200 32,100' 31.900 18,0001 10,000 8,500 9.800 12,000, 4,700 j 4.600 32,000 3.400 Yb Hf 6.000 Ba 270.000 Sr 46.000 Ta 0.600 2,700 10,000 117,000 U 24.600 35,300 U 4.500 0,900 9,000 0,700 1,800 6,200 21,800 ' 11,100 Nb 14,000 12,500 ' 8,000 13,900 15,700 Y 6,600 5,600 20,000 3,800 9,400 4,700 Sc 6,200 8.200 3,280: 2,880 31,000 15,300 i Th 10,600 6,0001 1,900 8,000 3,700; Ghi chu: TB kieu I = trung binh granite kieu I TB kieu S = tmng binh granite kieu (theo J.B.Whalen, 1987); Chi Le = trung binh granite cung nOi Ida kieu Chi Li (VAG) (Pearce 1984); Oman = trung binh granite (Syn-COLG) kliu Oman {Pearce 1984) Hdm luang nguyen to chinh theo % trgng lUang, nguyin td vet theo ppm Can ed v i o mde dd hoat ddng cCia ddi benioff cd the cua da nui Ida thude loat kiem - vdi va hau nhu ed t h i n h ehia eung hoat ddng (Active ares) va cung khdng hoat phan acid hoac trung tinh, ciJng ed l i bazo nhung rat dpng (Inative volcanic arcs) hoac tiiy theo mdi quan he hiem gap Chiing bao gdm cie cau tnic niii Ida phan tang vdi vd luc dja va dai duong de chia cung ria m i n g luc ma c h i l m Uu the la cic 6a m i n h vun nui Ida (pyroelastic) dja tiife la cung n i m tren luc dia nhung d g i n ria luc dia acid, cic Idp phu dung nham va ignimbrit h o i c dung va cung dao dai dUOng la cung n i m ben dai dUOng nhung thudng gan ria dai duong (K.CKondie, 1989) Cung ria m i n g luc dja dUpc d i e trUng bdi sU cd mat nham andesit va cic 6a phun t r i o cd phan trdn lan magma Cic khoang sin lien quan vdi cung ria luc kieu n i y cd cac md dien hinh tren the gidi gom 19 J Bdng Kit qud phdn tich hda hoc cdc nguyin td chinh vd nguyin td vit cdc dd magma h^ tdng Nha Trang, phu hi tdng trin M t i n g Nha Trang, phu h f t i n g t r i n 317/T2 C.527/3 TTOJ 46mi 47in'i S17/T2 525/T3 72.880 72,940 73,840 73,98C 74,000 74,320 0,120 0,110 0,130 0,13C 0,120 0,120 12,520 12,840 13,530 12,52C 12,830 12,520 1,110 1,480 1.1SC 1,150 1,320 532/T2 S38/T2 74.380 74,420 340/T3 P.17658 P.17655 P.17669 CJ65/1 C.477/1 CJ17/2 C.665/1 P.2S579 P.17724 P.17787 ChiLe 74,560 75,300 75,440 76,140 76.260 76,280 76JO0 76,580 76,880 78.220 78,800 0,140 0,120 0,150 0,150 0,130 0,140 0,140 0,090 0,140 0,140 0,350 0150 0,160 12.630 12,840 1,580 1,570 13,530 12,920 13,220 12,940 16,230 12,950 11.920 12,980 13,080 15.830 11,420 12,520J 1,150 0,470 0.130 1,270 74,500! 1,080 0,990 1.140 1.170 0,500 0.540 1,780 1,140 1,000 FeO 1,170 3,390 0,620 1,S3C 1,170 1,440 1.270 0,780 0,470 0,220 0,330 0,420 0,330 0.30O 1.910 0,330 0,450 560 0,420 0,000 MnO 0,015 0.160 0,022 0.03A 0,017 0,033 0.031 0,022 0,015 0,030 0,030 0.040 0,030 0.030 0,080 0.030 0,030 0.100 0,050 0,010; 0,190 Fe^Oj 1,110 MgO O,00qj_ 0,560 0,120 0,03C 0,060 0,000 0,120 0,000 0,000 0,050 0,050 0.050 0,090 0,090 0,180 0.140 CaO 0.4201 0,650 0,340 0,380 0,340 0,420 0.340 0,500 0,420 0,130 0,130 0,200 0,000 0,000 0,000 0.000 Na^O 3,320 3,200 3,710 3,770 3,660 3.730 3.750 3,460 3.870 3,350 3,090 3,070 3J00 3J90 3.410 5,170 4,240 5,020 4,700 4,890 4690 4,790 4,350 4.850 4,900 4,650 4.590 4J70 4,220 3.470 Pfi^ 0,004 0,000 0,000; 0,002 0,009 0,007 0,008 0,000 0.001 0,010 0,000 0,010 0,010 0,010 Mkn 2,670 0,000 i,bso| 0,870 0.950 0,890 0,860 1,030 1.680 1,530 1,040 0,270 0,830 HjO- 0,390 0,000 0,310 0,240 0,220 0,210 0,290 0,180 0,420 0.080 0,170 0,050 0,150 99,790, 99,200 100,170 99,300 100,210 99,750 99,290 99,050 102^10 1,830 1,880 1,959 K^O £ 100,170 99,340 99,420 99,700 1,893 1,828 1.878 1,883 1,865 0,382, 0,267 0,365 0,393 0.373 0,642"i 0,750 0,740 0,740 0,750 Logr 1.888 Logo Na/K 0,370 0.000 0,070 0,000 1740 0.000 0,290 3,240 2,240 3,080 2,490 3360 4.330 4,320 5.580 3,450 5310 0,000 0,000 0,000 0,040 0,020' 0,010 0,890 0,180 0,750 1,290 ciro" i',440' '0940 0,080 0,060 0,190 0,150 0,010 0,150 0,000 99,530 98,070 99,210 99310 102,430 99,430 99,560 1334 1,976 1,842 1,889 1,834 1,826 1.949 1,805 1341 1,775 0,355 0,366 0,288 0,266 0.024 0,259 0,241 0.153 032 aio4 0386 -0,006 0,780 0,800 0,276 0,600 0324 0,800 0,680 0,660 0,670 0,820 0,800 0,980 0,750 0.520 0.660 0,720 Sm 13,200 6.000 10,200 10,200 8,500 6,400 8,200 7,600 8,400 Ce 78,000 67/)00 96,000 68,000 71,000 56,000 81,000 9sjom 85,500 Yb 5.600 3,100 6,300 5,400 5,400 4,600 4700 4.000 196,000 10,000 326,000 10,000 71,000 395,000 10,000 mooo 131,000 238.000 175,000 Zr Rb Hf Ba 7,600 159W) 7,500 9,400 7,700 162,000 475,000 124000 110,000 Sr 38,000 249,000 10,000 38.000 Ta 1,000 0,800 1,300 1.000 La 38,000 U 2J00 Th ' 179,000 175,000 196,000 176,000 7,600 3,120 184,000l 169,000 7,400 5,730| 147,000 159,000 122.000 403.000 11.000 10,000 75,000 20,000 1,200^ 1J00 1,300 a900i 331,000| 7,700 &400 93,000| 1,750 40,100 ^Afioo 20,330j -j Sc 3,3000 4/400 3,600 3,900 3,400 3,800 6.800 Nb 11,9000 23,800 7,200 11,600 14,900 10,200 15,300 7,700 17,000J Y 6,8000 4,600 4,600 4,500 8,600 5.500 8.300 5,400 30,000] Ghi chu: TB kieu I = trung binh granite heu I TB l