川西南寒武系沉积体系分析

四川盆地川西南地区寒武系分布广泛，主要由海相陆源碎屑岩和碳酸盐岩及其过渡岩类组成。根据钻井、录井和测井等资料以及沉积相标志的综合分析，指出本区寒武纪早期（筇竹寺期和沧浪铺期）发育海相陆源碎屑沉积体系，主要包含陆源碎屑滨岸和浅海陆棚两种沉积相；晚期以发育碳酸盐岩台地沉积体系为特色，主要由碳酸盐潮坪、混积潮坪、半局限～局限海台地相组成。沉积特征和沉积相分布研究表明，区内物源主要来自西侧的康滇古陆，海域总体上表现出西北浅东南深的变化趋势，沉积相带呈北西—南东向错落有序分布。

CAMBRIAN DEPOSITIONAL SYSTEM IN SOUTHWEST SICHUAN

Cambrian strata wildly spread in southwest Sichuan and are composed of marine terrigenous clastic rocks and carbonate rocks. After analyzing the data of drilling, logging and well logging, as well as facies marks, it is suggested that terrigenous clastic depositional system was developed in Early Cambrian (Qiongzhusi Stage and Canglangpu Stage) and mainly includes terrigenous clastic shore and shallow shelf facies; carbonate platform depositional system was developed in late Cambrian and is mainly composed of carbonate tidal flat, mixing tidal flat, halfrestricted to restricted platform facies. Study on depositional characteristics and facies distribution shows that the material source of study area is from Kangdian old land, at that time the water depth progressively increase from northwest to southeast, and the distribution of depositional facies is orderly oriented in the direction from northwest to southwest.