吉林东部延边地区海沟—石人沟一带“槽—台”界线露头的发现及地质意义

在吉林东部朝阳屯等四幅1：5万区域地质调查过程中，于海沟－石人沟一带发现中元古代海沟岩群的大理岩与太古宙变钾长花岗岩在露头上呈韧性剪切带接触，并确认为这是在吉林省及其邻区首次发现的华北陆块北缘与其陆缘活动带的界线露头（即“槽－台”边界）。这一发现为研究该区的大地构造格架找到了确切的第一手资料，对重塑本区的“造山史”具有重要的意义。

Discovery of an Outcrop of a Geosyncline-platform Boundary in the Haigou-Shirengou Area of Yanbian, Jilin Province and Its Geological Significance

During a 1:50000 regional geological survey in Chaoyangtun, a ductile shear zone as the contact between the marble of the Neoproterozoic Haigou lithogroup and an Archean metamorphic monzonitic granite was discovered. It is confirmed that this is an outcrop of the boundary between the northern margin of the North China block and its active continental margin,i. e. , the boundary between a geosyncline and a platform. The discovery provides the firsthand material to study the tectonic framework and has an important significance to reconstruct the erogenic history of the area.