In Search of Ancient Colorado River Cobbles

Skunked again below Hoover Dam. Mostly Dacite lava and the more interesting Boulder City Pluton Quartz Monzonites with pretty chalcedony veins. The purple canyon floor area and piedmont slope below the extensive ash fall is Lower Patsy Mine andesite of the Eldorados at todays river elevation.

35.999487, -114.727353

Free geologic map of the Hoover Dam quadrangle:
https://pubs.nbmg.unr.edu/Geologic-map-of-the-Hoover-Dam-p/m102.htm

If you want to get down, down on the ground on YouTube:
https://www.youtube.com/watch?v=O6yeLNNVa4A

I was a dam builder on YouTube:
https://www.youtube.com/watch?v=bMdeg-WKt1U