华北石炭系清水、浑水沉积交互的模式初探

A Sedimentary Model for Interfingering Clear-Water and Turbid-Water Deposits

摘要:

地史时期中,清水与浑水沉积交互的现象非常普遍。这一沉积特征已引起了煤沉积学工作者的兴趣。华北石炭纪含煤岩系中的碳酸盐清水沉积常常受到陆源物质的强烈干扰,碳酸盐台地的存在与海水进退,古陆的“活跃”程度及沉积区、物源区的地形地貌等因素密切相关。在以上因素的综合作用下,台地或被陆源碎屑完全占据而消亡,或与之共存,在横向上犬牙交错形成了华北中晚石炭世陆表海清水、浑水沉积交互共存的复杂古地理景观。

Abstract:

It is an important feature that the clear-water carbonate and turbid-water terrigenous clastic deposits coexist and are imtercalated in Middle and Upper Carboniferous coal-bearing formations in North China. This phenomenon tends to be closely related to palaeogeographic settings, transgression and regression and topography in sedimentary and terrigenous areas. On the basis of sedimentary facies analysis of many Middle and Upper Carboniferous sections in North China, especially those in the Jungar coalfield on the northern margin of North China coal-bearing basin, the author has made an approach to the genesis of interfingering clear-water and tubid-water deposits and a tentative sedimentary model has also been proposed in this paper.