Organic Tissues in Tertiary Lacustrine and Palustrine Rocks from the Jiyang and Pingyi Rift Depressions, Shandong Province, Eastern China

  1. P. Anadón,
  2. Li. Cabrera and
  3. K. Kelts
  1. E. I. Robbins1,
  2. Zhou Zili2 and
  3. Zhou Zhicheng3

Published Online: 14 APR 2009

DOI: 10.1002/9781444303919.ch15

Lacustrine Facies Analysis

Lacustrine Facies Analysis

How to Cite

Robbins, E. I., Zili, Z. and Zhicheng, Z. (2009) Organic Tissues in Tertiary Lacustrine and Palustrine Rocks from the Jiyang and Pingyi Rift Depressions, Shandong Province, Eastern China, in Lacustrine Facies Analysis (eds P. Anadón, Li. Cabrera and K. Kelts), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303919.ch15

Author Information

  1. 1

    US Geological Survey, Reston, VA, 22092, USA

  2. 2

    Geological Research Institute of the Shengli Oilfield, Dongying, China

  3. 3

    Nanjing Institute of Geology and Paleontology, Nanjing, China

Publication History

  1. Published Online: 14 APR 2009
  2. Published Print: 6 SEP 1991

ISBN Information

Print ISBN: 9780632031498

Online ISBN: 9781444303919

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Keywords:

  • Introduction;
  • Geological Setting;
  • Sampling and Analytical Procedures;
  • Jiyang Depression;
  • Pingyi Depression

Summary

Organic tissues and acid-resistant minerals in Tertiary lacustrine and palustrine rocks from the Jiyang and Pingyi rift depressions in eastern China were analysed to determine if palynological techniques are useful where sedimentological techniques do not result in unique solutions. The study sites are two rifted, fault-block sub-basins of the North China Basin containing thick sequences of Lower Tertiary lacustrine rocks. The basins are so close to the sea today that periodic marine incursions could not be ruled out, but diagnostic marine fossils are lacking. Delicate dolomitic tubes thought to have been precipitated by marine algae, two seemingly similar coals, and an interbedded carbonaceous shale thought to have been deposited by an anoxic lake were analysed from the Shehejie Formation in the Jiyang Depression. ‘Polychaetic’ boundstone, thought to be the product of marine worms, carbonaceous micrite and an underlying terra rosa, and oncolites, were analysed from the Guanzhuang Formation in the Pingyi Depression.

Palynological analysis reveals that the algal filaments in dolomitic tubes are unlike modern marine algae, that the coals were produced by two different plant communities, and that the high pyrite content of the lower coal supports an influx of sulphate to the basin. The ‘polychaetic’ boundstone tufa contains plant cells; re-examination of a thin-section shows that the tubes were produced by reed-like plants having hollow stems and polygonal leaves. Tissues in the carbonaceous micrite and terra rosa suggest that the depositional regime was one of a wetland resting on a mottled and gleyed aquitard-forming soil. The oncolites are composed of masses of intertwined filaments, thereby supporting a biotic interpretation for their production. In all, the organic tissues show that lacustrine and palustrine conditions dominated the depositional regime in the sub-basins, but that periodic marine incursions cannot be ruled out as a source of sulphate.