地质学报2011，Vol.85Issue(3)：323-329,7.
金川超基性岩体形态演变对矿区构造的制约
Morphological Evolution of the Ultrabasic Rocks in the Jinchuan Mine Area and Its Constraints on the Tectonic Process
摘要
Abstract
Jinchuan ultrabasic rocks can be divided into the south rock belt and the north rock belt. The north rock belt consists of No. I and No. Ⅲ rock bodies, and the south rock belt consists of No. Ⅱ and No. Ⅳ rock bodies. Two belts are located on the north and south sides of marble tectonic lens. Before the emplacement of ultrabasic rocks, the peak metamorphism and deformation with a high amphibolite facies occurred in the paleo-Proterozoic strata and a thrust-nappe-type ductile shear sliding system was developed along the bedded marble, forming the layer metamorphism rock slice characterized by inverted metamorphic belt, structural migmatite, shear rheological fold and marble tectonic lenses. During the emplacement of ultrabasic rocks, due to regional extension, the tensional-shear fractures were formed in both sides of the marble tectonic lens in brittle-ductile tectonic level, and ultrabasic rock was emplaced in the lens-shape tensional-shear fractures from deeply magmatic chamber, forming the south rock belt and the north rock belt characterized by left-lateral en echelon arrangement in the plane. After the emplacement of ultrabasic rocks, with the thrust-nappe extrusion from SW to NE, the ultrabasic rocks as well as ore bodies not merely generated ductile deformation, and produced NEE-trending arc-shaped reverse-strike slip greenschist facies ductile shear zone, which offset the south rock belt and the eastsection marble about 1 km toward NE in the plane, resulting in that the south rock belt linked up to the west-section rest body of north rock belt, and the south rock zone increased integrally and the eastern section of the north rock belt decreased integrally, which was lie concealed in the deep of north side of eastsection marble. Therefore, exploring the hidden north rock belt should be the future strategic exploration orientation in the Jinchuan copper-nickel sulfide deposits.关键词
超基性岩体/侵位机制/岩体形态/成矿预测/铜-镍矿床/甘肃金川Key words
ultrabasic rock body/ emplacement mechanism/ rock-body morphology/ metallogenic prognosis/ copper-nickel deposits/ Jinchuan in Gansu province引用本文复制引用
汪劲草,汤静如..金川超基性岩体形态演变对矿区构造的制约[J].地质学报,2011,85(3):323-329,7.基金项目
本文为广西自然科学基金项目(编号桂科自0728221,0832251)资助的成果. （编号桂科自0728221,0832251）
