赣北安源煤系沉积对构造活动的响应

著名的“安源煤系”沉积于晚三叠世至早侏罗世,而赣北又是“印支运动”表现强烈的地区之一,这样,赣北的安源煤系便成为研究构造-沉积响应的理想目标层位。研究表明,安源煤系沉积作用对构造活动的响应主要表现为沉积速率的变化,沉积相带沿推覆方向的迁移,以及碎屑岩成分的垂向变化。

TECTONIC-SEDIMENTATION RESPONSES OF THE ANYUAN COAL SERIES, NORTH JIANGXI

The famous Anyuan Coal Series was deposited during the so-called Indosinian Movement, when the South China Block collided with and overthrust onto the Yangtze Block in early Mesozoic. The response of the Anyuan Coal Series in the process of its sedimentation to the Mesozoic collision tectonics is discussed in the present paper.The northwestword multiple nappe-thrusting in provenance, which resulted from conti-nen-continent collision, caused the variation in sedimentary thickness and rate. In front of the nappe, sedimentary rate was slower and hickness smaller, with some unconformities developed. On the contrary, in distal area, sedimentary rate was faster and thickness larger, without any unconformity. At the same time, the northwestward thrust of nappes resulted in migration of the sedimentary facies zone in the same direction. By thrusting, the nappes lifted and underwent erosion. Their decollement history is reflected in the vertical variation in conglomerate composition in the Anyuan Coal Series.The research is a part of the China-Swiss cooperative program, which is financially supported by both the Chinese National Natural Science Foundation and the Swiss Federal Institute of Technology.