Abstract:

The analyses on the data of drilling, cores, well logging and tectonic patterns of Qiongdongnan Basin showed that the coal beds in Yacheng Formation mostly formed by the gelatification and were deposited in the environment of peat swamp in the braided channel delta plain and the peat swamp environment of the epilittoral zone and upper eulittoral zone. In the early Yacheng Formation, the main coal-forming depositional system was the braided stream-braided channel delta system. In the middle and later periods of Yacheng Formation, the main coal-forming depositional systems were the tide flat-lagoon system. The affecting factors for incoalation were comprehensively analyzed. Six kinds of coal-forming models in Qiongdongnan Basin were developed on the basis of the sedimentary environment and tectonic configuration. The coal-forming models include the alluvial fan forepart and braided channel delta plain model, tide flat-lagoon model, shallow sea peripheral fan delta and littoral zone model, deepwater half-graben sag model, shallow-water half-graben sag model and deep-water graben sag model.

Key words: Qiongdongnan Basin, Yacheng Formation, incoalation, coal-depositional environment, coal-forming model, sedimentology characteristics

摘要：

对琼东南盆地钻井、岩心、测井、构造形态等资料进行了系统分析，阐述了琼东南盆地崖城组成煤作用、成煤环境及成煤模式。崖城组的成煤作用主要为凝胶化作用；煤层多发育在辫状河三角洲平原泥炭沼泽环境和潮坪的潮间带上部、潮上带泥炭沼泽环境；主要的成煤沉积体系在崖城组早期主要为辫状河三角洲体系，在崖城组中、晚期主要为潮坪—泻湖体系。在综合研究各种影响成煤作用因素的基础上，从沉积环境和构造形态角度建立了6种主要的聚煤模式，即冲积扇扇前和辫状河三角洲平原聚煤模式、泻湖—潮坪聚煤模式、浅海周缘扇三角洲和滨海带聚煤模式、深水半地堑凹陷聚煤模式、浅水半地堑凹陷聚煤模式、深水地堑凹陷聚煤模式。

关键词: 琼东南盆地, 崖城组, 成煤作用, 成煤环境, 聚煤模式, 沉积学特征