北准噶尔增生杂岩带重磁场特征及构造解译

摘要

The distribution of regional gravitational fields and aeromagnetic fields are analyzed through systematic statistics of the magnetic and density parameters of the main rocks and ores from North Junggar in Xinjiang. The northern Junggar can be divided into three Bouguer gravity anomaly units and five aeromagnetic anomaly districts. The Bouguer and aeromagnetic anomaly belts indicate the presence of accretionary complex zone at the active continental margin in northern Junggar. The complex is wedge-shaped and is limited by the Altay-Fuyun fault zone at the north, the east margin of Kazakhstan Plate at the west, and the Almantaio phiolitic melange belt at the south. This accretionary complex zone consists of several N-E trending accretionary units. The deep-geophysical sounding profile of the Altay region indicates that the subduction resulted in the formation of the accretionary complex zone.%通过系统统计新疆准噶尔北部地区主要岩矿石磁性、密度参数，重点研究了该区航空磁场、区域重力场分布规律。按照布格重力和航磁异常形态，准噶尔地区可以划分为三个布格重力异常单元和五个航磁异常单元，认为北准噶尔地区的布格重力异常和航磁异常揭示该区可能为一陆缘增生杂岩带。该增生杂岩带形态上呈“锲形”，其北缘位于阿尔泰–富蕴断裂一带，西部与哈萨克斯坦板块毗邻，南部边缘为阿尔曼太蛇绿混杂岩带。该增生杂岩带由多个增生单元“拼贴”而成，具北东向凸起特点。阿尔泰–阿尔金地学断面揭示了增生杂岩带深部俯冲形态。本次研究成果为研究新疆北部与邻区大地构造提供了新的依据。