Turbidite, Slump and Debris Flow Deposits at the Kalchinskoe and Zimnee Oilfields, West Siberian Basin

Abstract

This paper discusses specific facies associated with Cretaceous deep‐water slumps and sandstone intrusions in the West Siberian Basin. The slumps were formed during sea‐level falls when storms caused sediment masses to be discharged into deep‐water areas where they imposed a significant load on the underlying semi‐consolidated black shales, deforming and partially destroying them. Multiple slump / avalanche events are observed at the boundary between the Lower Cretaceous (Neocomian) and Upper Jurassic (Tithonian) sequences and form potential targets for oil exploration. High‐resolution sequence stratigraphic analyses show that both slump and distal fans are genetically related to lower slope/basin floor sediments and were deposited during regressions and subsequent lowstands. Two key depositional environments are recognized: the proximal parts of fans, where the most prospective potential reservoirs are found; and the more distal parts of slumps, which are principally composed of deformed shale clasts in a silt‐mudstone matrix. A third facies (“slump head”) is only observed on seismic profiles and is probably related to horizontally displaced “shingled” semi‐consolidated black shales.

Review of the deformation styles during the Cretaceous Tethyan period: inferred from slumps and fault Kinematics analysis along Northern Tunisia

“…After this long extensional Tethyan period, a positive basin inversion was operated during the Late Cretaceous (Guiraud and Bosworth 1997;Dlala et al 2002;Mabrouk et al 2005;Masrouhi et al 2008;Bey et al 2012;Bejaoui et al 2017;khelil et et al 2021a). Within active and passive margin patterns, the main driving agent for triggering softsediment deformations is recognized to be the gravity-driven forces over an inclined submarine basin floor (Woodcock 1979;Mills 1983;Khafizov and Syngaevsky 2005;Shanmugam 2006a; Strachan and Alsop 2006;Owen and Moretti 2008;Alsop and Marco 2014;Kukla et al 2018;Li et al 2019;Rodrigues et al 2021;Warsitzka et al 2021). Moreover, mass transport deposits have been reported in seismic and outcrop studies in recent years (Faerseth and Saetersmoen 2008;Posamentier and Martinsen 2011;Sharman et al 2015;Basilone et al 2016c).…”