25 February 2014

Carbonate mudcracks in cross-section (Tonoloway Formation)

Posted by Callan Bentley

While on Corridor H 2 weeks ago with Alan Pitts, we stopped astride the Patterson Creek Mountain Anticline, with extensive road cuts displaying Tonoloway Formation overlying Wills Creek Formation. We love this spot for its lovely folds and halite casts. See what I mean?

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This time, however, my eye was drawn to the prodigious quantities of mudcracks to be seen in side-view (that is, in cross-section). Take a gander:

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Zooming in on the crack betwixt the concave-up “dishes: of finely laminated carbonate mud:

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Here’s another example:

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And another:

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And one more, from the other (sunny) side of the road…

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What do these features look like when viewed from “above,” that is, viewed on the bedding plane itself (rather than in cross-section)? We’ve proudly displayed them before:

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That last GigaPan is at a quarry on old Route 55, on the west flank of the Hanging Rock Anticline.

Students: What can we infer about conditions in West Virginia during the Silurian period of geologic time, when these rocks were deposited as sediment?