Sedimentology and sequence stratigraphy of the Paleogene lower second member of the Shahejie Formation, W79 Block, Wenliu Oilfield, Bohai Bay Basin, China

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• 作者：J. Li^a ; J. Zhang^a ; ^b ; ^{jinliang@bnu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; S. Liu^a ; Z. Fan^b ; H. Xue^b ; Z. Sun^b ; T. Yu^b
• 关键词：Distributive fluvial complex ; Wenliu Oilfield ; W79 Block ; Shahejie Formation ; sequence stratigraphy ; sedimentology
• 刊名：Russian Geology and Geophysics
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：57
• 期：6
• 页码：944-957
• 全文大小：7684 K

文摘

High-resolution stratigraphic analysis of the lower second member of the Shahejie Formation of the W79 Block of Bohai Bay Basin, China, has revealed that the study area, previously interpreted as a shallow water delta system, actually mainly originated in a subaerial setting with a distributive pattern. Depositional systems of the distributive fluvial complex (DFC) have been recognized. The regional correlation of the lithofacies within the different depositional systems has led to a high-resolution-stratigraphic framework of two long-term base level cycles, six middle-term base level cycles, and more than 58 short-term base level cycles. Sequence boundary SB1 marks the top of the target interval and is characterized by thick and continuous mudstone overlying sand-rich channel sediments. Sequence boundary SB2 marks the bottom of the target interval and is characterized by stably distributed shales between sand-rich sediments. The base-level fluctuation has a strong tectonic component consistent with the regional tectonic setting; during the active subsidence stage, base-level rising semicycles were recorded in the strata, and during the relatively stable stage, base-level falling semicycles were recorded.