Evolution of sedimentation pattern in a continental rift basin of India, between the Late Triassic and the early Middle Jurassic: Tectonic and climatic controls

Article Type

Research Article

Publication Title

Sedimentary Geology

Abstract

The spatial and temporal pattern of sedimentation in a rift basin is a result of complex interplay between tectonically induced vertical crustal movement and climatic condition. Though the conceptual and numerical models for tectono-sedimentary evolution of half grabens are available, the stratigraphic arrangement of lithofacies produced by the environments on hangingwall block is poorly documented till date. Additionally, the stratigraphic record resulting from the interactions between the hangingwall processes and those of the basin trough is less known. The purpose of this work is to delineate the tectonic and climatic factors controlling the distribution of sedimentary environments from the stratigraphic architecture of a Late Triassic to Early Jurassic syn-rift strata of a continental half-graben of India. This work also aims to characterize the deposits formed in the transitional environments that occur in between the fluvial system of the hangingwall dip slope and the lacustrine system at the basin trough. This work involves a detailed sedimentological study including facies analysis and palaeocurrent analysis. The studied syn-rift sediments record i) a changeover from axial to transverse fluvial system in the end of Triassic, ii) transition from fluvial to lake marginal environment in the Early Jurassic and iii) evolution of an extensive palustrine system in the Middle Jurassic. The corresponding changes in lithological and geochemical characters for the first change points towards incresed tectonic movement along the main boundary fault that caused the progradation of the hangingwall fans towards the basin trough. Later changes can be attributed to the reconfiguration of the sedimentary environments due to increase in aridity that influenced the introduction of coarse clastics to the basin.

DOI

10.1016/j.sedgeo.2020.105679

Publication Date

7-15-2020

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