Magnetic Fabric Studies of Sandstone from Jhuran formation (Kimmeridgian-Tithonian) of Jara Dome, Kachchh Basin, Northwest India

Low-field anisotropy of magnetic susceptibility (AMS) study was performed on the clastic sandstones of the Jhuran Formation from the Jara dome in the Kachchh basin. The AMS results consistent with petrographic analysis indicate primary deposition fabric for Arkose, sub-litharenite, wacke and quartz arenite sandstones of the Jhuran Formation. Isothermal remanent magnetization and thermal demagnetization curves indicate that magnetite, titano-magnetite and hematite are the chief magnetic minerals contributing to the AMS. The distribution of K₁, K₂ and K₃ axes in the stereographic projections suggest depositional fabric development for arkose, sub-litharenite and wacke, whereas dispersed K₃ axes for quartz arenite are inferred to be due to low strain activity. The shape factors T, q confirm the oblate-shaped ellipsoid and horizontal fabric respectively, for all samples. The reconstructed palaeoflow directions for arkose and sublitharenite are NW-SE and for wacke and quartz arenite are NE-SW based on K₁ AMS axis.