地球化学
地毬化學
지구화학
GEOCHIMICA
2001年
1期
24-34
,共11页
葛文春%李献华%李正祥%周汉文%李寄嵎
葛文春%李獻華%李正祥%週漢文%李寄嵎
갈문춘%리헌화%리정상%주한문%리기우
过铝花岗岩%岩石成因论%地球化学%地幔柱%广西壮族自治区
過鋁花崗巖%巖石成因論%地毬化學%地幔柱%廣西壯族自治區
과려화강암%암석성인론%지구화학%지만주%엄서장족자치구
广西北部新元古代花岗岩类岩石包括黑云母花岗闪长岩和黑云母花岗岩。地球化学特征表明,黑云母花岗闪长岩与含堇青石的过铝花岗岩(CPG)相当,而黑云母花岗岩则类似于白云母二长花岗岩(MPG)。黑云母花岗岩类是成熟地壳岩石部分熔融作用的产物,而黑云母花岗闪长岩类的形成与地幔柱起源的镁铁质岩浆和地壳起源的过铝质黑云母花岗岩浆之间的混合作用有关。这两类新元古代过铝花岗岩的形成与碰撞造山导致地壳加厚的挤压性构造无关,而与导致Rodinia超大陆裂解的地幔柱上升诱发岩石圈伸展的张性构造相联系。
廣西北部新元古代花崗巖類巖石包括黑雲母花崗閃長巖和黑雲母花崗巖。地毬化學特徵錶明,黑雲母花崗閃長巖與含堇青石的過鋁花崗巖(CPG)相噹,而黑雲母花崗巖則類似于白雲母二長花崗巖(MPG)。黑雲母花崗巖類是成熟地殼巖石部分鎔融作用的產物,而黑雲母花崗閃長巖類的形成與地幔柱起源的鎂鐵質巖漿和地殼起源的過鋁質黑雲母花崗巖漿之間的混閤作用有關。這兩類新元古代過鋁花崗巖的形成與踫撞造山導緻地殼加厚的擠壓性構造無關,而與導緻Rodinia超大陸裂解的地幔柱上升誘髮巖石圈伸展的張性構造相聯繫。
엄서북부신원고대화강암류암석포괄흑운모화강섬장암화흑운모화강암。지구화학특정표명,흑운모화강섬장암여함근청석적과려화강암(CPG)상당,이흑운모화강암칙유사우백운모이장화강암(MPG)。흑운모화강암류시성숙지각암석부분용융작용적산물,이흑운모화강섬장암류적형성여지만주기원적미철질암장화지각기원적과려질흑운모화강암장지간적혼합작용유관。저량류신원고대과려화강암적형성여팽당조산도치지각가후적제압성구조무관,이여도치Rodinia초대륙렬해적지만주상승유발암석권신전적장성구조상련계。
The Neoproterozoic granitoids in northern Guangxi consist ofbiotite granodiorite and biotite granitoids. The geochemical characteristics indicate that biotite granodiorite is equivalent to cordierite-bearing peraluminous granitoids (CPG), while biotite granitoids are similar to muscovite-monzonitic granite (MPG). Biotite granitoids are the result of partial melting of mature crust, and the formation of biotite granodiorites are related to the mixing of mantle plume-derived mafic magma and crustal-derived peraluminous biotite granitic magma. The formation of these two types of Neoproterozoic peraluminous granitoids is irrelevant to the compressional structures caused by collisional orogney which led to crustal thickening, but relevant to extensional structures caused by the ascent of mantle plume which led to the breakup of Rodinia supercontinent.