黑龙江漠河盆地构造特征与成盆演化

对漠河盆地的地层层序、构造特征和构造单元、盆地演化过程等进行了研究。漠河盆地盖层主要为侏罗纪陆相煤系地层及白垩系火山岩，属典型的二元结构。晚侏罗世中期由于蒙古—鄂霍茨克洋的关闭，额尔古纳微板块与西伯利亚板块碰撞，使盆地西部产生逆冲推覆构造，地层缩短量在64km以上。晚侏罗世晚期到晚白垩世，盆地进入西太平洋构造域演化阶段，处于拉张环境，在盆地中部和东部发生了三期大规模的火山活动，形成火山断陷盆地。因此，漠河盆地经历了蒙古—鄂霍茨克洋和西太平洋两种不同构造域的演化阶段，具有西部挤压推覆、中部和东部拉张断陷构造特点。

Tectonic Characteristics and Basin Evolution of the Mohe Basin, Heilongjiang Province

Studies have been conducted to analyze the stratigraphical sequence, tectoric characteristics and basin evolution of the Mohe Basin in Heilongjiang Province. The results suggest that the Mohe Basin is located in the collision sutures of E'erguna micro-plate and Siberian Plate, belonging to Mongolia-Okhotsk fold belt. Its foundation consists of the Triassic metamorphic rocks and the Cambrian granites, and the sedimentary covers are mainly terrestrial coal formation (Jurassic) and the volcanic rocks (Cretaceous) with a typical dual structure. Because of the closing of Mongolia and Okhotsk Ocean and the collision of Siberian and E'erguna micro-plates, the western part of the basin produced cover structure in the opposite direction, and the strata was shortened more than 64 km in the Early Jurassic. During the Early Jurassic and the Late Cretaceous, the basin was affected by west Pacific tectonic evolution and was in extension environment. The volcanic and faulted basin was formed because the volcanic activities took place on a large scale three times in the middle and western parts of the basin. Because the Mohe Basin has experienced two kinds of evolution i.e., the Mongolia, Okhotsk and west Pacific ocean structural evolution, therefore, the basin is characterized by compression in west part, extensional, faulted structures in the middle and east parts.