新疆伊犁盆地南缘中新生代以来构造演化与聚煤规律研究

新疆伊犁盆地以其丰富的煤碳和铀矿资源倍受专家与学者的高度关注,特别是伊犁盆地南缘。笔者从煤矿勘查角度,运用构造地质学、煤田地质学、沉积学的理论,从构造应力作用强度方面阐述伊犁盆地南缘现存的构造特征、构造格局以及含煤地层中下侏罗统水西沟群的沉积特征和赋煤性。笔者分析了古气候和沉积环境与聚煤关系,认为水西沟群是在温暖潮湿古气候条件下形成的冲积扇-扇三角洲体系的产物,有利于泥碳沼泽环境的形成,特别是西山窑组具备形成稳定而厚大煤层的基本条件。笔者重点分析中新生代以来的构造演化过程对煤矿的形成与保护作用,认为区域构造背景直接决定了盆地的形成与演化,从而影响着研究区成煤环境与赋煤潜力;构造格局或构造特征是成煤后构造演化的结果,即其活动影响着煤层成藏或保存程度;构造作用的差异性影响着煤层的保存状态和分布范围。

Tectonic Evolution and Coal Accumulation about the Southern Margin of Yili Basin in Xinjiang since Middle Cenozoic Era

The Yili basin is famous for its rich resources of coal and uranium, especiallyin the southern margin of this basin. From the angle of coal exploration, the tectonic pattern, sedimentary characteristics and coal bearing strata of the Middle-Lower Jurassic Shuixigou Group in the southern margin of the Yili basin have been studied in this paper through using the theory of structural geology, coal geology and sedimentology. After studying and analyzing the paleoclimate and sedimentary environment that related to coal accumulation, it's believed that the Shuixigou Group is a product of alluvial fan-fan delta system that formed in the warm and moist climate, whichis beneficial to the formation of peat swampenvironment, especially the Xishanyao Formation has basic conditions for forming stable and thick coal seam.This paper focuses on analyzing how the structures evolution since Millde Cenozoic era affect and control the formation and mineralization of coal. The results show that the regional tectonic background determinesthe formation and evolution of the basin, thus affecting the coal forming environment and coal potential in this studying area. The structure or structural features serve as the results of tectonic evolution after coal-forming, that is, the tectonic activities affect coal accumulation orpreservation, and the difference of tectonic activities impact the preservation state and distribution of coal seam.