Undulatory base of Mulberry Member, Bandera Formation

Exposure of Mulberry Member between the varicolored claystone
unit below and the Worland Limestone above. Note the rise in the
base of the Worland Limestone toward the right. The undulating
base of the Mulberry lies just above the pick. The surface
separating the varicolored claystone from the Mulberry appears
to be partly erosional here, as the red iron-oxide-stained layer at
the base of the Mulberry is missing where the contact is especially
low (left of the pick head)--erosion during Mulberry time removed
the sediment that eventually came to host the iron oxide. This
contact is nearly parallel to the undulating base of the overlying
Worland, suggesting that compaction has also played a role in
shaping this surface; the contact conforms to the configuration of
the base of the relatively incompactible limestone. To the left of
the pick, the lowermost Mulberry includes a thin layer of impure
coal ("smut"). In the left half of the photograph a lenticular zone of
richly fossiliferous olive gray calcareous shale splits the
carbonaceous zone of the Mulberry.

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