Friday Field Foto #31: Deltaic channel-fill deposits

This week, a photograph from southern Chile.

Although we’ve been focusing on the turbidite deposits in Patagonia, we also have a project investigating the shallow-marine and deltaic deposits that overlie them. Put simply, the turbidite formation was fed by a delta system that was advancing basinward and essentially filling in the basin with sediment during the Late Cretaceous (~70-80 million years ago). So, overlying the turbidites for hundreds of kilometers are younger deltaic deposits.

The below is a nice shot of sandstone-rich distributary channel-fill deposits that are encased in fine-grained carbonaceous mudstone, which is interpreted as interdistributary bay fill. The white circle is a person for scale. Note the basal erosional surface of the sandstone body, cutting down into the fine-grained strata from left to right.

Happy Friday!

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