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本文根据重大地质问题野外地质调研、锆石SHRIMP年代学与岩石地球化学研究,揭示出秦岭造山带腹地明显存在晋宁期和加里东期的两期叠加板块汇聚结合带。新提出晋宁期具主次两条板块汇聚结合带,系中新元古宙古中华陆块群裂解—古秦岭多岛洋形成(1800~940 Ma),可识别出具蛇绿岩、岛弧火山岩与深成侵入岩、陆缘弧变质地层四位一体的组合,时空紧密关联。北部即古华北南缘古商丹带,沿北秦岭南缘被后者商丹带重叠,南部为古扬子西北缘板块汇聚结合带,总体延伸近北东向,从三湾(西乡)、黑木林、峡口驿、三岔子、鞍子山、马道、佛坪至小磨岭以东。其南段受扬子地块燕山期向北推挤位错,三湾蛇绿构造混杂岩带呈构造窗出露,中段遭晚期东西向勉略带构造捋顺。而早古生代Rodinia超大陆裂解——原特提斯洋形成(561~447),认为消失的原特提斯洋是中国最具规模的早古生代大洋,商丹—昆南板块汇聚带,便是中国大陆造山带最重要的一条大地构造界线。研究了两期板块汇聚结合带分布与区域成矿关系,对铁、铜、镍钴等区域成矿前景赋予新的启示。
Based on the field geological survey of major geological problems, zircon SHRIMP chronology and geochemical study of rocks, it is revealed that there are obvious convergence zones of Jinning period and Caledonian in the hinterland of the Qinling orogen. It is proposed that the convergence zone of the two main plates in the Jinning Period was newly formed. The Mesozoic Neoproterozoic paleoclimate group was formed during the formation of the ancient Qinling multi-oceanic crust (1800 ~ 940 Ma) and could be identified as ophiolite and island arc Volcanic rocks and deep into the intrusive rocks, continental marginal arc metamorphic formation of the four-in-one space-time closely linked. The northern part of the ancient Shangdan belt along the southern margin of the ancient North China is overlapped by the latter Shangdan belt along the southern margin of the north Qinling Mountains. The southern part is the converging belt of the plate in the northwestern margin of the ancient Yangtze, extending generally to the NE direction. From Sanwan (Xixiang) Blackwood, Gap mouth station, three goats, saddle Hill, Ma Road, Foping to grind to the east. The southern segment was pushed northward by the Yanshanian period of the Yangtze block. The Sanwan ophiolitic melange belt was exposed by the structural window and the middle segment was constructed by the late east-west Mianluo belt. The Early Paleozoic Rodinia supercontinental pyrolysis - the original Tethys Ocean Formation (561 ~ 447), that the disappearance of the original Tethys Ocean is China’s largest early Paleozoic ocean, Shangdan - Kunnan plate convergence zone, is The most important tectonic boundary in the orogen of mainland China. This paper studies the relationship between the convergence zone distribution and regional metallogenesis in the two plates, and gives new enlightenment to the metallogenic prospect of iron, copper, nickel, cobalt and other regions.