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Tap chi Nghien cdu va Phat triSn, so 4 (102) 2013 DA GABRO d THl/A THIEN HUE VA VAN DE KHAI THAC, Si/ DUNG Biii van Nghia" 1 L^i noi dau Gabro (gabbro) la nh6m da macma (magma), di rgc hinh thanh do s[.]
Tap chi Nghien cdu va Phat triSn, so (102) 2013 DA GABRO d THl/A THIEN HUE VA VAN DE KHAI THAC, Si/ DUNG Biii van Nghia" L^i noi dau Gabro (gabbro) la nh6m da macma (magma), di.rgc hinh sii ddng cufng ciJa nhOiig khoi silicat nong chay Ngifcfi ta chia da macma loai: macma xam nhap (khi khoi nong chay dong dac d dudi sau nhu da granit, diorit, gabro) va macma phun trao (khi dung nham trao len mat da't mdi dong dac nhu da liparit, andezit ) Da macma ra't bien tren Trai da't va tim thay or nhieu noi nhu chau My, chau Phi, chau A O Viet Nam da macma phan bo ph6 bi§'n d mien Bac, mien Trung, Tay Nguyen va m6t so noi khac Tuy nhien su co mat cua da gabro d cac lanh th6 neu tren khong nhieu, dac biet d Viet Nam da gabro chi phan b6' han che d mot vai noi nhu Thanh Hda, Nghe An, ThUa Thien Hu§' O ThUa Thien Hue cac phdc he macma-gabro duoc nghien cUu tii kha lau, tap trung mot sd c6ng trinh ldn: Ban dia cha't dai TrUdng Son va cao nguyen Ha Lao ty le 1/1.500.000 cua R Bouret (1925), J Hoffet (1993), Ban dia chat Dong Duong ty le 1/2.000.000 cda J Fromaget (1952), Ban dia chat Viet Nam (phan phia Nam) ty le 1/500.000 cua Tran DiJc Luong, Nguyen Xuan Bao va imk (1983), Ban dia cha't va tim kiem khoang san loat td Hue-Quang Ngai ty le 1/200.000 cua Nguyen Van Trang va nnk Ban dia cha't va khoang san nhdm td Nam Dong ty le 1/50.000 cua Vu Manh Dien (1988-1993) Nhu:ng dac tn^ng cua da gabro u Dac triing ve sti phdn bd Trong pham vi ThUa Thien Hue dd macma phan bd rd't bie'n va da dang: Phdc he Dieng Bong (khu Tam Boi phia tay bac A Ludi): phan chu ye'u la da plagiogranit; Phdc he A Bung (tay nam A Ludi): cd gabro nhUng khong phd bie'n; Phdc he Trd Bdng (phan bd td xk Hong Trung, A Ludi): diorit thach anh, granodiorit; Phdc he Dai Loc (A Roang, A Ludi): granit biotit pocphy dang gflnai (gneis); Phdc h§ Que Son (khu vUc Nam Dong): gabro biotit, granit biotit; Phdc hd Chd V^n (phia bic Nam Dong, Phu Loc va Khe Day): gabro pyroxenit, gabro hocblen; Phdc he Hai Vdn (phdn bd d Hai Vdn, Bach Ma, Mang Ca ): chu ye'u dd granit; Phdc he Bd Na (phan bd' d Ben Tuan, Song Bo): granit biotit Trong cac phdc hd ndu tren, dd gabro chu ye'u cd mat d Phu Lpc, Nam Dong vdi dien tich khong ldn, thudc phdc he Chd Van (v a T, cv) phan bd nhdng Trucing Cao dang Cong nghiep Hue Tap ch! Nghiin cdu vS Phit trifo, sd (102) 2013 dai nhd bao quanh khd'i granit Bach Ma thudc phdc hd Hai Vdn (v a T^ hv) ve phia bMc Chung tao ndn dia hinh dang vdng cung dugc lien kd't vdi tai mot sd' di^m nhd Xudn Ldc, Ldc Diln, Ldc An (Phu Ldc), Huong Hdu (Nam Ddng) Ngodi dd gabro cdn phdn bd' mdt vai dien tich nhd d dinh nui Bach Ma va khu vUc Apei, huygn A Ludi Su phan bo' cua cdc the gabro diu lien quan de'n hg thd'ng ddt gay chinh vung theo phugng tdy bdc-ddng nam vd a VI tuyd'n Td dd cho tha'y chung dugc hinh thdnh td dudi sdu vd trdi da't vd dugc chuyen len nhd cdc hoat ddng cua ddt gay Theo chieu sdu dd gabro phdn bd hai tang khd rd tU tren xud'ng; - Tang tang lan dd gabro rat dac trung, phan bd' tren be mat cdc ddi thoSi, cd chilu day td vai mdt dd'n vai chuc mdt Kich thudc cua cac tang ldn thudng ldn de'n ra't ldn vd tdp trung trdn bl mdt bao mdn ciia cdc tang da gd'c Chat lugng da gabro tang lan kha td't, dg nguydn khdi cao Day Id dd'i tugng quan de khai thdc, suf dung ldm nguyen lieu san xua't dd d'p ldt Cac tang lan dd gabro dugc hen kit vdi bdi tdng da't mdu nau do, vdng cd phan cat, set phong hda tU da go'c gabro - Tang dd gd'c gabro phdn bd d vung Ldc Dien, Ldc Hoa, huyen Phd Lpc vd Huong Hdu, huyen Nam Ddng tren dien tich khoang 18km^ Da gabro gdc Id vdi dien tich nho phat hien d vung tha'p, ven sUdn ddi, ndi, bl mat dd bi phong hda, bao mdn, nut ne manh Phan ldn da gabro phdn bd dudi sau vai chuc met tao nguyen khd'i ldn, rdn chdc, mau tucfi sam Thanh phan thach hgc la gabro amfibon hat ldn de'n nho Day Id nguon tai nguyen tiem ndng (dat khoang trieu m^) cd the dugc thdm dd, khai thac, sd dung thdi gian tdi Bgc triing ve thdnh phdn, mdu sdc Khoi gabro khu virc nghien cdu dugc cau thdnh bdi loai da chinh: gabro amfibon va gabrodiorit [3] Gabro amfibon phdn bd phd bie'n khu vUc Phu Ldc nhu Ldc Dien, Lpc Hda Dd cd mau den pha ddm nhd mau xdm trdng hoac tap hop dom nho kilu hoa dau Thdnh ph^n khoang vat chu ye'u tao nen da:'Hocblen 55-75%, Plagiocla 15-25%, Pyroxen 10-20% Gabro diorit phan bd' tugng dd'i phd bie'n khu vuc nghien cdu, tap trung d Lpc Dien, Ldc Hda (Phd Loc), Huong HOu (Nam Ddng) Da cd mau xam den, xam tro, xen cac hat nhd mau xdm trdng Thdnh phdn khoang vat chinh cua da: Hocblen 29-45%, Plagiocla 40-60%, Pyroxen it gap 3-5% Dac trung cua da gabro la ty le khoang vat sam mau tdng (hocblen, pyroxen, olvm ), ham lugng hda hgc SiO, giam (