Journal of Geology & Geophysics
Open Access

Earthquake induced soft sediment deformation structure in a paleoproterozoic extensional basin, Vempalle Formation, Cuddapah Basin, India

International Conference on Geology

June 22-23, 2015 Florida, USA

Gopal Chakrabarti, Debasish Shom, Madhumita Panja and Linda C Kah

Posters-Accepted Abstracts: J Geol Geosci

Abstract :

Soft sediment deformation structures (SSDS) are preserved in homogenous dolomudstone lithology of crinkly laminite and heterolithic facies of Paleoproterozoic (Orosirian) Vempalle Formation of the Cuddapah basin formed on eroded basement of Eastern Dharwar Craton, Peninsular India. While ductile deformation structures as preserved in this succession include boudins or pinch and swell structures, diapirs, convolute bedding and folds whereas intrastratal faults, syn-sedimentary breccias, cracks and vein-arrays belong to brittle deformation regime. On basis of the observed SSDS, their lateral homogeneity and traceability, draping by undeformed strata, proximity of faults as well as apparent lack of storm signatures and gravity induced mass movement. These fine grained deformed beds can be tentatively ascribed to a large, intermediate depth earthquake with magnitude approximately 4 and above, generated during reactivation of basement faults owing to plume related mantle activity. The occurrence of SSDS in Vempalle Formation emphasizes the role of down-warping along pre-existing planes of weakness in the Archean basement in the later evolution of Cuddapah basin analogous to subsidence in present day continental margin subsequent to thermal subsidence during the initiation of Cuddapah basin.