Oil & Gas Geology ›› 2022, Vol. 43 ›› Issue (1): 186-195.doi: 10.11743/ogg20220115

• Petroleum Geology • Previous Articles     Next Articles

Characteristic differences of glauconite formed in different geologic periods and related genetic analysis

Qin Zhang1,2(), Chen Zhou3, Hanyun Tian1, Kai Wang1, Zeping Song1, Qishi Dong1   

  1. 1.College of Geosciences,China University of Petroleum (Beijing),Beijing 102249,China
    2.State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China
    3.Shengli Oil Production Plant of Shengli Oilfield Branch,SINOPEC,Dongying,Shandong 257000,China
  • Received:2021-01-10 Revised:2021-08-31 Online:2022-02-01 Published:2022-01-28

Abstract:

Glauconite with significance of indicating facies is complex and diverse in occurrence, composition and genetic mechanism, and widely developed in different geologic periods. The differences in respects of characteristics and genetic mechanism of glauconite developed in various geologic periods are investigated based on a review of previous researches from a large number of related case studies worldwide, with a view to improving the genetic theory of glauconite and providing a scientific basis for paleogeographic analysis. The results show that the occurrence of glauconite formed in different periods can be classified into three groups, that is the granular, cemented and halo edged groups. The granular group in turn can be subdivided into four types in terms of substrate. The Precambrian glauconite is mainly developed in substrate of quartz and K-feldspar, featuring high content of K2O and high maturity, which can be interpreted via pseudo-shape replacement theory in genetic mechanism. The Phanerozoic glauconite is preferably developed in initial substrate containing fecal spherulite and bioclastic materials, featuring unstable K2O content as its potassium component mainly derived from seawater, and its genetic mechanism is closely related to contents of K2O and Fe2O3, to which layer lattice theory and granular glauconization theory are more appropriate for interpretation. An integrated analysis of sedimentary environments and ion sources of glauconite in the various geologic periods, indicates that areas adjacent to Fe-redox contact surfaces with sufficient supply of cations such as Fe, K, Al, Si and Mg are favorable for the formation of glauconite.

Key words: genetic mechanism, maturity, occurrence, sedimentary environment, glauconite

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