Sedimentary environment of Fengcheng Formation in Urho area, Junggar Basin
Online published: 2014-04-06
Fengcheng Formation in Urho area of Junggar Basin is an important exploration horizon, and there has been some controversy to its sedimentary environment. This paper explored sedimentary facies mark, facies types and characteristics of Fengcheng Formation by studying rock and mineral sedimentary structures, paleontological and geochemical characteristics. We discovered that the sedimentary environment of Fengcheng Formation is epicontinental offshore lake in deep-water, with blocked anoxic and high salinity. This formation mainly developed the deposition of semi-deep lake facies which can be divided into three sub-facies: hydrothermal pulsatile jet deposition, low-density turbidite sand and ash flow micro-facies. Mineral salts enrichment, high salinity and the horizontal distribution of hydrothermal exhalative sedimentation are obviously controlled by the Permian basement fractures in Wuxia area, and this fractures were presumed as channel for high temperature and high salinity brines hot jet activity. Based on all these studies, we established a hydrothermal exhalative model of the epicontinental offshore lake, mixed with internal and external sedimentary sources of Fengcheng Formation, which could further guide the oil and gas exploration in this area.
SHI Zhanzhan , PANG Su , TANG Xiangrong , HE Zhenhua . Sedimentary environment of Fengcheng Formation in Urho area, Junggar Basin[J]. Lithologic Reservoirs, 2014 , 26(2) : 59 -66 . DOI: 10.3969/j.issn.1673-8926.2014.02.010
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