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Geoscience ›› 2021, Vol. 35 ›› Issue (01): 281-292.DOI: 10.19657/j.geoscience.1000-8527.2021.01.28

• Ore Deposits and Geochemistry • Previous Articles     Next Articles

Application of High-resolution Chemical Sequence Stratigraphy to Deep-water Fine-grained Sediments:A Case Study of Wufeng Formation and Lower Member of Longmaxi Formation in Liutang Outcrop, Upper Yangtze Area

WANG Qian1(), HUANG Yongjian1(), ZHANG Zhifeng1, WANG Changhong1, LI Xiang1, LIU Wei2   

  1. 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083,China
    2. Chengdu Center, China Geological Survey, Chengdu, Sichuan 610082,China
  • Received:2020-07-16 Revised:2020-08-25 Online:2021-02-12 Published:2021-03-12
  • Contact: HUANG Yongjian

Abstract:

Based on the theories and methods of chemical stratigraphy and sequence stratigraphy, the data of Liutang outcrop profile and sample analysis and test in Shizhu County of Chongqing are used to optimize the indicators system for the chemical sequence stratigraphic division which are the elements assemblages of Al-K-Ti-Rb-Cr-Zr, related to input intensity of terrigenous, the elements assemblages of Ca-Mn-Mg-Ba-Zn, related to autogenetic precipitation intensity, and the elements assemblages of V-Ni-Mo-U-As related to organic matter adsorption and deoxidation intensity. The Wufeng Formation of Liutang outcrop is divided into LCW sequence, and the lower part of Longmaxi Formation is divided into MCL1-1, MCL1-2, MCL1-3, MCL1-4 sequences upwardly. The total amount of major and trace element combinations related to the input intensity of terrigenous source is relatively high near the sequence boundary, but relatively low near the most oceanic flooding surface, which has the cyclic changes characteristics of decreasing-increasing of total elements. However, the total amount of major and trace element assemblages related to autogenetic precipitation, organic matter adsorption and deoxidation intensity are generally lower near the sequence boundary and higher near the maximum flooding surface, which has the cyclic changes characteristics of increasing-decreasing the total amount of elements. The cyclic change characteristics of the total amount of element assemblages with different genetic signi-ficance is the response of regional sea level change, which has regional consistency and can be used as the basis of regional stratigraphic correlation.

Key words: Upper Yangtze area, Liutang outcrop, Wufeng Formation, Longmaxi Formation, chemical sequence stratigraphy

CLC Number: