湘西北杨家坪处于鄂中碳酸盐台地西缘，寒武纪期间区内先后出现大洋缺氧事件、浊流事件、风暴事件等突发性灾变沉积。根据黑色岩系的岩石学特征和它产于急速海侵的层序底部，以及它在我国南方和世界性广泛分布等事实，表明它的出现是与震旦－寒武纪之交的外星撞击地球、泛大陆解体、全球性海平面突然上升有关。浊流事件和风暴事件均为强烈的地方性灾变事件，前者的产物为磷质浊积岩和钙质浊积岩，其诱发因素与风暴活动有关；后者为具冲刷底界的近源风暴岩和具刨蚀底界的原地风暴岩 Yangjiaoping in the northwestern Hunan Province is located in the western margin of carbonate platform in Hubei Province. During the Cambrian period, sudden catastrophic sedimentation such as oceanic anoxic event, turbidity event and storm event occurred successively. According to the petrological characteristics of the black rock series and the bottom of its sequence of rapid transgression, and its widespread distribution in the south of the country and beyond, it shows that its appearance was that the alien collided with Earth at the turn of Sinian to Cambrian , The disintegration of the pan-continent and the sudden rise of global sea level. The turbidity events and storm events are both intense catastrophic catastrophic events. The former products are phlogopite turbidite and calcareous turbidite, and the triggering factors are related to storm activity. The latter is near-source storm with erosion bottom Rocks and in-situ storm rocks with a planing bottom