Application of Sequence Stratigraphy to Precambian Strata—A case study on the Sinian in Western Henan Province

Key words: 
• sequence stratigraphy /
• the Sinian /
• type l sequence /
• sequence isochronic framework /
• curve of sea-level changes

Abstract: The paper focuses on sequence stratigraphy of the Sinian in Western Henan Province. Based on the theory of sequence stratigraphy,three type I sequences have been identified, in which the first two sequences correlate to the Huanglianduo Formation and Dongjia Formation,respectively,and the third one includes both the Luoquan and Dongpo Formations. After establishing their sequence isochronic framework,the author analyzes systematically the distribution patterns and genetic relations of the strata and sedimentary facies zones within the framework,and then proposes that the formation of the Sinian sequences and their system tracts in the study area was controlled primarily by the relative sea-level changes. The sediments which deposited within the same sea-level changes,although they have different sedimentary environments and different components, are isochrononic and can be correlated. Finally,the author proposes a method how to drove the curves of relative sea-level changes. Based on the research result,the author concludes that the theory of sequence stratigraghy can be generally applied to the Precambian,such as the Sinian,by identifying the key boundaries,especially the sequence boundary (SB) and the maximum flooding surface (mls),and analyzing the features of the parasequences,parasequence sets and system tracts within a sequence. The method establishes a good base for the classification and correlation of the strata study. But the hierarchy of the sequence cannot be precisely determined because of low-studying-level and short of accurate dating,therefore further studies are necessary.