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Neoproterozoic Molar‐tooth Structure and Constraint of Depositional Facies and Environment in the North China Platform in Jiangsu, Anhui and Liaoning, Eastern China
Author(s) -
Yongqing LIU,
Linzhi GAO,
Yanxue LIU
Publication year - 2005
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.2005.tb00919.x
Subject(s) - facies , geology , sedimentary depositional environment , dolomite , paleontology , carbonate , deposition (geology) , calcite , sedimentary rock , sedimentary structures , geochemistry , geomorphology , sediment , structural basin , materials science , metallurgy
Molar tooth structure (MTS) represented by complex ptygmatical shapes is widely distributed in the Proterozoic of the world. MTS filled by fine, equant sparry calcite (or dolomite) displays an abrupt contact with hosting rocks, which are mainly composed of carbonaceous micrites and fine‐grained carbonates with local silts and stormdominated deposits with graded, cross or wave beddings, numerous erosional surfaces and truncated and fills or guttered bases. Occurrence of MTS suggests a result of the constraint of sedimentary facies, and the storm‐base in ramp settings is the maximum depth for the formation of MTS. Vertical succession of MTS‐bearing carbonates shows a deposition stacked by high‐frequency shallow subtidal and peritidal cycles. An individual cyclic MTS‐bearing sequence is characterized by thinning, shallowing and dynamic decreasing‐upward, and peritidal caps of purple red iron and organic carbonaceous sediments with more complicated shapes of MTS are common on the top of individual MTS‐bearing sequences.