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Chalk Mountain, Horseshoe Reservoir, Arizona

Chalk Mountain, Horseshoe Reservoir, Arizona

That's not snow! This is Chalk Mountain adjacent to the Horseshoe Reservoir on the Verde River.

According to Wrucke and Conway (1987, USGS OFR-  ), Chalk Mountain consists of white to light-gray, finely laminated limestone. Chert also occurs but is minor. Small centimeter-scale stromatolite-like mounds suggest an origin as algal mats growing on a paleo-lake bed. The authors suggest the deposit may be correlative with the Plio-Miocene Verde Formation. 

For the report and map: https://pubs.er.usgs.gov/publication/ofr87664

Image courtesy of Google Earth.

Photographer: Mike Conway

Photo Date: 2017