@mike_malaska@deepspace.social
2026-04-05 18:12 UTC
Ripple marks in Death Valley.
Furnace Creek formation. Golden Canyon just below Manly Beacon.
How did this form?
1) About 9 million years ago during the Miocene-Pliocene, there was a big deep lake here. It was dry, but mot as dry as current Death Valley.
2) Muds, silts, sands, and volcanic tuffs were deposited in the lake building up a thick sequence of layers.
3) Nearby rhyolite got altered by hrdrothermal activity.
And then...
#Geology
#DeathValley
Replies (1)
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@mike_malaska@deepspace.social 2026-04-05 18:24
4) Those hot solutions percolated through the layers, emplacing extracted borate minerals into little weak gaps or cracks between layers. (As you can see in pic below). (This would be commercially mined later for borate. "Twenty Mule Team" fame.) 5) Later faulting, shifting, shrink-swelling made those mud layers go all over the place. In this location it looks like the layers were almost vertical. So some old ripple marks in lakebed muds are hanging there like a framed picture hung on a wall.