T123 GSA Sedimentary Geology Division/SEPM (Society for Sedimentary Geology) Student Research Poster Competition: Dynamics of Stratigraphy and Sedimentation (Posters)

Monday, 23 September 2019
9:00 AM - 6:30 PM
Hall AB, North Building

CYCLICAL MIXED-SILICICLASTIC CARBONATE SEDIMENTARY SYSTEM IDENTIFICATION AND CHARACTERIZATION IN LACUSTRINE ENVIRONMENT: AN EXAMPLE FROM HUANGHEKOU SAG, BOHAI BAY BASIN, CHINA

Paper number: T123-28
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

  • Sen Li Presenting Author
    China University of Geosciences(Wuhan), Wuhan
  • Hongtao Zhu
    China University of Geosciences（Wuhan）, Wuhan

Abstract

As a critical and unique sedimentary system, mixed deposits derived from the interaction of different processes in the same basinal sector have been mostly studied in continental shelf, carbonate platform, or other marine settings. However, less studies have concerned about lacustrine mixed sediments, which is considered as a key in interpreting paleogeographic setting during the sedimentation period. During the deposition of Eocene Es1 formation in Bohai Bay Basin, a critical petroliferous basin of China, widely distributed mixed deposits have been found in various sub-basins because of the relatively stable tectonic activity and arid climate. A detailed analysis of both lithofacies and stratigraphic architecture of a mixed-siliciclastic carbonate depositional system in the Eocene Es1 formation of Huanghekou sag, Bohai Bay Basin, is carried out. Five different lithofacies are recognized and classified based on core observation, microscopic description and whole-rock X-ray diffraction analysis, including (A) calcite/dolomite-cemented conglomerate, (B) calcite/dolomite-cemented sandstone, (C) grain dolostone/limestone, (D) micrite dolostone/limestone and (E) mud shale. Besides, lithofacies C can be divided into two sub-facies, C1 has abundant inter- and intra-granular porosity, while C2 has most of its pores filled with calcite/dolomite cements. These facies associations are believed to have deposited in various depositional environments with differential-hydrodynamic conditions. Vertical stratigraphic analysis displayed there existed meter-scale cyclically interbedded mixed-siliciclastic carbonate rocks comprising parts or all five lithofacies, indicating a high-frequency rhythmicity of hydrodynamic conditions.

Geological Society of America Abstracts with Programs. Vol. 51, No. 5

doi: 10.1130/abs/2019AM-341314

© Copyright 2019 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.