丝绸之路经济带阿尔泰次经济区地质矿产研究的突破——古亚洲古生代洋壳板块及对成矿控制的新认识

A Breakthrough in Study on Geology and Mineral Resources of the Circum-Altay Economic Subregion along the Silk Road Economic Belt:A New Understanding of the Palaeo-Asian Palaeozoic Ocean Plate and its Control on Metallogeny

在对中亚阿尔泰山系及邻区的构造格架研究中,在西伯利亚前寒武纪陆壳板块和东欧-塔里木-中朝前寒武纪陆壳板块之间划分出一个重要的一级构造单元,本文将其称为古亚洲古生代洋壳板块,进而划分出北古亚洲早古生代多岛洋壳板块、中古亚洲晚古生代多岛洋壳板块、南古亚洲早古生代多岛洋壳板块。另外,还对次级构造单元进行了划分。中生代以后,这一板块就成为统一的欧亚大陆板块的一部分。与构造单元的划分相对应,对成矿单元进行了划分。在古亚洲古生代成矿域的基础上,划分了北古亚洲洋早古生代成矿省、中古亚洲洋晚古生代成矿省、南古亚洲洋早古生代成矿省。还对其次级成矿单元进行了详细划分,较好地解决了成矿系列和成矿预测等有关问题。研究成果还提出:前陆盆地和山间盆地是能源矿产聚集的有利场所;俯冲带和火山岛弧带是层控火山岩型黑色-有色-贵金属矿产的赋矿空间;陆岛和变质混合岩地体是花岗伟晶岩型稀有金属和工业用白云母矿床的富集地段;构造裂解的喷发岩和斑岩则是斑岩铜(钼)矿床的集中产地;新陆壳的应力松弛区的碱性岩带是稀有矿床产生的优良场所,据此优选了70多处各类矿床的预测区。本研究将对丝绸之路经济带阿尔泰次经济区的进一步找矿和开发提供重要借鉴。

In the study on tectonic framework of Altay mountain system and adjacent territories located in the vast area between the Siberian Precambrian continental plate in the north and the East Europe-Tarim-Sino-Korean Precambrian continental plate in the south,a major tectonic unit can be identified,called the Palaeo-Asian Palaeozoic ocean plate.This tectonic unit can be subdivided into three multi-island ocean-crustal plates,including(1)the North Palaeo-Asian Early Palaeozoic plate,(2)Central Palaeo-Asian Late Palaeozoic plate and(3)South Palaeo-Asian Early Palaeozoic plate.In addition,they can be further subdivided into secondary tectonic units.From Mesozoic on,they constituted a part of the Euroasian continental plate.Corresponding to the division of tectonic units,the divided Palaeo-Asian Palaeozoic metallogenic mega-province can be subdivided into three corresponding tectono-metallogenic provinces,i.e.,(a)North Palaeo-Asian Early-Palaeozoic province,(b)Central Palaeo-Asian Late-Palaeozoic province and(c)South Palaeo-Asian Early-Palaeozoic province.These metallogenic provinces also can be subdivided into secondary metallogenic units.This division properly interpreted problems of metallogenic series and metallogenic prognosis of the region.Moreover,the results of study suggest that the foreland basins and intermontane basins are the favorable places for accumulation of energy mineral resources;the subduction zones and volcanic island-arc belts are the lodging points of mineral resources of ferrous,nonferrous and precious metals of volcanogenic stratabound types;the continental islands and terrains of metamorphites and migmatites are the enrichment regions of deposits of rare metals and industrial muscovite of pegmatitic type;and the zones of tectoclase with development of effusive rocks and porphyries are the localities of porphyry copper(molybdenum)deposits.Besides,the zones of stress relaxation of new continental crust with development of alkaline rocks are the fine spaces for the formation of rare and rare-earth metals.Based on the understandings above,70 prognostic regions for deposits of different types are preferred,probably providing help for further mineral prospecting and development in the Circum-Altay economic subregion along the Silk Road economic belt.