中上扬子地区早寒武世梅树村期岩相古地理

根据野外露头剖面,采用单因素分析多因素综合作圈法,对中上扬子地区早寒武世梅树村期进行了定量岩相古地理研究,编制了中上扬子地区梅树村阶的单因素图及相应的岩相古地理图.所谓单因素,指的是能独立地反映某地区、某地质时期、某沉积层段沉积环境某些特征的因素,它的有无或含量的多少均可独立地反映该地区、该层段沉积环境的某些特征,如沉积环境水体的深浅、能量大小、性质等,均可作为单因素.通过对选定的单因素逐一分析,并作出单因素平面等值线图,从各单因素图的分析入手,再通过各单因素图的叠加和综合分析判断,最后作出定量的岩相古地理图.这一方法的核心即为定量.本次编制的定量岩相古地理图各古地理单元的划分都有确切的单因素数据,这是首次以期为单位编制中上扬子地区定量岩相古地理图.根据研究区沉积背景和梅树村期岩相古地理单元在平面上的展布总结出了沉积模式.梅树村期,本区西部发育滇中陆、川滇陆、牛首山陆,北部发育山阳-浙川陆、汉南陆和鄂中陆,西部陆的周围为细碎屑岩滨岸,向海方向依次发育碳酸盐岩台地、碎屑岩陆棚及页岩-硅质岩半深海一深海.这种定量古地理图中古地理单元的划分由于有定量的数据作依据,能够更加细致和精确的反映古地理面貌,因此在油气和其他矿产资源的勘探中有着更加重要的指导意义.

Lithofacies Palaeogeography of the Meishucun Age in the Middle and Upper Yangtze Region

Based on the observation on outcrops, using the single factor analysis and comprehensive mapping method, the single factor maps of the Meishucun Stage, the lithofacies palaeogeographic maps of the Meishucun Age were compiled. The single factors in this paper mean the factors which can independently reflect some characteristics of sedimentary environments of a stratigraphic interval of a section in an area. Presence or absence as well as high or low percentage of single factors can all independently and quan...