Organic Evolution Of Benxi Formation In Benxi

Carboniferous strata are widely distributed in North China, and well developed in the east of Liaoning. Benxi Formation is a set of marine-terrigenous facies,and named by Zhao Yazeng in 1926,and well-known in the word.It exposed well in Benxi,such as Niumaoling, Yaoziyu, Kongjiapuzi and so on. There are many geological paleontologists have reported the formation and paleontology about Benxi Formation. This paper mainly studied the subsidence history and the evolution of sedimentary organic matter.This paper studied the lithology and sedimentary sequence about Benxi Formation in Niumaoling, Yaoziyu and Kongjiapuzi, and measured the Yaoziyu section. Experiment about vitrinite reflectance was made by 4 species of Ro samples which selected from 9 species in the Formation. We infer that the evolution of organic matter in the Formation long-flame coal to lean coal stage. According to the study, the subsidence history of coal bed of Benxi Formation is contains three stages. The palaeoenvironment of Benxi Formation showed river, coastal swamp to the marine-terrigenous facies deposit.