基于重磁场特征对阿尔金造山带与柴达木盆地构造分界线的认识

Research on the Tectonic Boundary between the Altun Orogen and the Qaidam Basin Based on the Characteristic of Gravity and Magnetic Fields

阿尔金造山带与柴达木陆块接触部位构造运动复杂,形成了北东向的巨型断裂带。盆山接触关系以断裂带北部的伊吞布拉克—索尔库里断裂为界,前人对此认识比较统一,但由于该区域地质工作程度低,缺乏有力的地质和地球物理证据。通过对最新取得的区域重力及以往的航磁数据进行处理和研究,发现断裂带南缘的石棉矿—牛鼻子梁—俄博梁断裂存在明显的重力异常和磁力异常高值带,综合分析认为该断裂才是构造分界线,并在区域地质调查中得到了一些印证。这一新的发现有可能对这一地区的盆山关系和矿产研究产生一定的影响。

The tectonic movement of contact parts of Altun orogenic belt and the Qaidam block is complicated,forming agiant north-east fracture zone.The Braque-Solcuri fault in the northern part of the fault zone is the boundary of the contact relationship between the basin and mountain and predecessors are more unified in this understanding.However,due to the low degree of geological work in this area,there is lack of geological and geophysical evidence.By researching on the latest regional gravity and processing the past aeromagnetic data,it is found that there exists obvious gravity anomaly and high-value magnetic anom-aly in the fracture of southern margin of Asbestos-Key beam-Obo beam.The comprehensive analysis shows that the fault is the true tectonic boundaries and has been confirmed in the regional geological survey.This new discovery is likely to have a certain impact on the relationship between the basin and the mountain and mineral research in this area.