Debris Flow Laterites and Bauxites at Naredi, Kutch, Western India

D. V. Chitale

Reworked laterites and bauxites at Naredi, India, occur as lateritic pebbly mudstone underlain by bauxitic bouldery mudstone and nodular bauxites. The boundary between lateritic pebbly mudstone and bauxitic bouldery mudstone is wavy and sharp, suggesting deposition in two distinct phases. The bouldery bauxites share a diffuse boundary with nodular bauxites. The laterite pebbles float in a yellowish-brown muddy matrix. The boulders and nodules of bauxite are embedded in a massive white clayey matrix. The pebbles and boulders are randomly oriented and are either internally massive or composed of smaller clasts. The occurrence of bauxite boulders over bauxite nodules gives an appearance of inverse bedding. Based on these characteristics, a debris-flow mechanism is proposed for the deposition of laterites and bauxites at Naredi. Deposition occurred as two debris-flow pulses. The bauxites were deposited first, followed by laterites. Smaller clasts are present within the larger clasts, which s ggests that the bauxite and laterite clasts had been reworked several times before finally being deposited. The residual, insitu laterites and bauxites capping the hills around Naredi were apparently source rocks for the debris-flow deposits. Deposition is speculated to have occurred during the Miocene-Pliocene.

AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.