Longmen Mountain The Qingping Klippes Determining The Formation And Evolution

For the last several decades, many geologists have researched Longmen Mountains Thrust Belt in-depth, their works have deepened the understandings of the related theories and guided the oil and gas exploration in the Longmen Mountains and the west sichuan foreland basin. Among them, the study of klippes, whose typical features are famous in the world, is always being a hot topic. Yet the study of Qingping Klippe in the North and Middle part of Longmen Mountains is relatively weak. Even now, opinions vary. Some people believe it is a big klippe structure, Another ones regard it as a superposition of several nappes. The author, aiming at this circumstance exactly, studies the features, formation and evolvement of Qingping Klippe, obtains some conclusion.According to the field investigation and interior analyses, we have researched the structure, genetic mechanism and evolvement of Qingping Klippe, demonstrated the existence of the Qingping Klippe, described its characteristic ,and divided it into 5 layers , the most in klippe zone of the Longmen Mountains, with the geometric features , physical makeups , deformations, and the rules of kinematics and dynamics.Some study have been done with contrast on the foundation mentioned above in order to recognize the klippe's geologic characteristic and distribution. The division of klippe proves that Qingping Klippe is a overlapping klippe, which is composed of five layers. According to the internal structural features and the mechanical origin, these layers can be devided into two kinds: thrust nappes and gliding nappes. Layer Ⅰ and Layer Ⅱ are thrust nappes ,while Layer Ⅲ, Layer Ⅳ and Layer Ⅴ are gliding nappes. This phenomenon that thrust nappes and gliding nappes appear in a same klippe has not been found in the else klippe in Longmen Mountains, and illustrates the view that Longmen Mountains klippe zone caused by thrusting earlier, and slipping later.The gliding nappes have typical features. The superstratums are distorted more mildly than the underlayers on the deformation. This showes that the upper ones rebuild the under ones, as a result, the earlier klippe are stronglier deformed. We consider that Qingping Klippe came from the back Longmen Mountains thrust nappes through the study of rhizosphere of klippe and its geological features. After Yanshanian- Himalayan stage, Layer Ⅰ - Ⅱ, which are formed in indo-chinese...