Petroleum Science >2018,??Issue 2:??230-251 DOI: https://doi.org/10.1007/s12182-017-0211-0
Sequence architecture and sedimentary characteristics of a Middle Jurassic incised valley, western Sichuan depression, China Open?Access
文章信息
Sinopec Exploration & Production Research Institute, Beijing 100083, China,Sinopec Exploration & Production Research Institute, Beijing 100083, China,State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China,Xinxing Geophysical Department, Bureau of Geophysical Prospecting, CNPC, Zhuozhou 072751, Hebei, China,Daqing Oil Company, CNPC, Daqing 163000, Heilongjiang, China,State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China and State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China
文章摘要
in the western Sichuan foreland basin. Ancient LMVs newly discovered in this area were further studied based on sequence
stratigraphy and seismic sedimentology. The aim of the present study was to investigate the sedimentary characteristics,
sequence architecture, and the controls on LMV deposition in this tectonically active basin using field survey data, seismic
sections, seismic amplitude imaging, core description, and comprehensive application of drilling data. The results show the
following: (1) Three regional sequence boundaries and two flooding surfaces were recognized, and the Shaximiao Formation
was divided into two-third-order sequences and four systems tracts. (2) Three sedimentary facies associations were
identified: incised valley-fill, tributary channel, and overbank facies. Incised valleys are 5–17 km wide, 20–60 m deep and
traceable for 120 km along their axes. (3) In the downstream segment, the role of tectonism gradually diminishes, and
periodic base-level changes control the form and evolution of the incised valleys. Three types of LMVs—A1, A2, and
A3—developed with changes in base level (lake level); of these types, the base level of the A3 LMV was likely the lowest.
關鍵詞
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Sequence architecture, Sedimentary characteristic, Lowstand meandering valley, Western Sichuan depression, Shaximiao Formation