甘肃的大地构造相与成矿

CHARACTERISTICS AND RELATIONSHIP WITH MINERALIZATION OF TECTONIC FACIES IN GANSU PROVINCE

本文简要叙述了大地构造相的概念,将其定义为在陆块区和造山系(带)形成演变过程中,在特定演化阶段、特定大地构造环境中,形成的一套构造岩石组合,是表达大陆岩石圈板块经过离散、聚合、碰撞、造山等动力学过程而形成的地质构造作用的综合产物。根据甘肃的大地构造相的划分和基本特征,将甘肃省大地构造相划分出相系5个、大相12个、相31个,进一步划分亚相178个。探讨了大地构造相与成矿的关系,认为成矿作用是在一定的大地构造背景下发展演化的,不同的成矿作用也离不开大地构造环境的制约。天山—兴蒙造山系相系成矿均与岩浆弧相关,金矿点众多;华北陆块区相系赋存岩浆熔离型铜镍矿床及稳定陆块区煤、铁、锰、磷、铝土矿等;塔里木陆块区相系赋存铁锰铜铅金、铬、钨、钼、硫铁矿、菱镁矿、萤石、磷钒矿、硼矿;秦祁昆造山系相系独是甘肃省最主要的成矿区带,具有多层次、多阶段的板块构造体制(大地构造相)的发展和演化,发育有铜铅锌钨金等多金属矿床;西藏—三江造山系相系以古老基底地层组成的古岛弧、古弧后盆地及新元古代陆缘裂谷亚相有关,以金和铜为主,另有重晶石、锰、磷等。讨论了优势大地构造相与空间表达。

Tectonic facies, defined as a rock-tectonic association formed in a tectonic setting of a specific tectonic site in a specific evolutionary stage during the formation and evolution of a continental block and an orogenic system（belt） as well as an integrated product of dynamic processes of divergence, convergence, collision and rotation-shear of continental lithosphere plates. The tectonic facies are divided into 5 facies series, 12 facies groups, 31 facies and 178 subfacies. The mineralization is developed under the background of a certain tectonic setting, and the tectonic environment also restricts the mineralization. The mineralization is related with magmatic arc in Tianshan-Xiangan Mongolian orogenic belt, Magmatic Cu-Ni deposits in North China Block, and Coal, iron, manganese, phosphorus, bauxite deposits in stable blocks, and iron-manganese-copper-lead-gold, chromium, tungsten, molybdenum, magnesite, pyrite, fluorite, phosphorus vanadium ore and boron ore in Qinling- Qilian-Kunlun orogenic belt. As the most significant metallogenic zone in Gansu Province, Qinling-Qilian- Kunlun orogenic belt has the development and evolution characteristics of the plate tectonic system in the multi- level and multi stage, and marked by Cu-Pb-Zn-W-Au deposits. The authors also analyzed the spatial- temporal structure of tectonic facies.