Abstract:

Early Silurian sedimentary rocks in Sichuan area were formed in the foreland basin stage during the period from the Late Ordovician to the Early SilurianIn Longmaxi Age of the Early Silurian，the study area was mainly a restricted deep shelf In Xiaoheba Age，it behaved as the expansion of the shallow shelf and reduction of the deep shelf，and the sedimentary differentiation was intensifiedThe palaeogeographic framework was the coexistence of carbonate platform，shallow and deep shelvesIn Hanjiadian Age，it mainly was the tidal flatshallow shelf environmentsEarly Silurian in the study area showed an evolutionary trend of shallowing fillingup and regression，and was characterized by blending continental shelf with multisourcesThe distribution of sedimentary systems and sedimentary evolution was controlled by the NWdirection squeezing of the foreland upheaval zone including the Qianzhong upheaval from the Late Ordovician to the Early SilurianThe development of the favorable reservoir body was mainly dependent on the sedimentary environmentsThe seashore sand bank and carbonate platform margin were the favorable reservoir body belts such as the“Xiaoheba sandstone”in eastern Sichuan area and the bioherm limestone in southern and northern Sichuan area

摘要：

四川地区早志留世沉积岩系形成于晚奥陶世—早志留世的前陆盆地演化阶段。早志留世龙马溪期主要为局限的深水陆棚环境。小河坝期表现为浅水陆棚的扩展和深水陆棚的萎缩，沉积分异作用加剧，呈现出碳酸盐台地、浅水陆棚、深水陆棚共存的古地理格局。韩家店期主要为潮坪-浅水陆棚沉积。早志留世四川地区表现为沉积盆地充填变浅和海退式的演化趋势，具多物源的混合型陆棚沉积性质，沉积体系展布和沉积演化主要受包括黔中古隆起在内的前陆隆起带的NW方向扩展作用控制。有利储集体的发育主要取决于沉积环境，浅海砂坝和碳酸盐台地边缘相是有利的储集相带，如川东地区的“小河坝砂岩”和川南及川北地区发育的生物礁灰岩。