新疆天山地区下石炭统出露广泛且与下伏地层多呈角度不整合接触,如西部北天山的大哈拉军山组,中部中天山的马鞍桥组及东部南天山的甘草湖组均与下伏地层呈角度不整合接触。显然,这是一个区域性角度不整合。两套地层间的角度不整合是鉴别造山运动的直接标志之一,此不整合可能暗示了古天山洋在早石炭世前已经闭合碰撞造山并进入陆内伸展演化阶段。 The Lower Carboniferous in Tianshan area of ​​Xinjiang is widely exposed and has many angles of unconformity contact with the underlying strata. For example, the Dahalajushan Formation in the northern Tianshan Mountains, the Saddle Bridge Formation in the central Middle Tianshan Mountains, and the Licorice Lake Formation in the southern Tianshan Mountains in the east The underlying strata are not angularly in contact. Obviously, this is a regional perspective that is not integrated. The unconformity between two sets of strata is one of the direct indications for identifying orogenic movement. This unconformity may imply that the paleo-Tianshan Ocean had closed collision orogeny before the Early Carboniferous and entered the stage of intracontinental extensional evolution.