Abstract

Six facies are recognized in Talchir strata exposed as a small outlier in Archean metamorphics. Markov chain analysis reveals a fining-upward relationship from conglomerate at base through sandstone to shale at top. Conglomerate facies are similar to those of longitudinal bars of proglacial outwash plains. Diamictite enclosed in conglomerate is interpreted as ice-rafted frozen blocks of moraine. Massive, horizontal-bedded to cross-bedded sandstone facies correspond to seasonal channel sand, deposited respectively as flooded channel facies and downcurrent-migrating transverse-to-linguoid bars of braided streams. Fine clastic facies correspond to periods of minimal discharge in protected or abandoned parts of outwash plains. Frequent lateral shifts of braided channel bars in outwash plains may account for the recurrence of fining-upward cycles. Deposition is attributed to meltwater streams following southward retreat of the Talchir ice lobe.--Modified journal abstract.

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