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

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