Friday, August 3, 2012

Pinnacles above Midas

Small pinnacles in volcanic rocks just above the town of Midas.

These relatively small pinnacles are located in the canyon of Midas Creek, just north of the town of Midas, Nevada.

The rock formation is probably either the Tlb or Tpm of Wallace (1993), with both units being part of the thick Miocene volcanic section erupted during formation of the northern Nevada rift, or eastern northern Nevada rift (NNRe) of Glen and Ponce (2002).
The pinnacles are two shadowy dots on the ridgeline near the center of this MSRMaps airphoto, west of an in-canyon set of builings and trees.
The [semi] coressponding MSRMaps topographic map indicates that the pinnacles are less than 40 feet high. I would guess that they aren't even 20 feet high, based on my mid-July, driving-through-canyon perspective.

A Few References:
Glen, J.M.G, and Ponce, D.A., 2002, Large-scale fractures related to inception of the Yellowstone hotspot: Geology, v. 30, no. 7, p. 647–650.

Leavitt, E.D., Spell, T.L.m Goldstrand, P.M., and Arehart, G.B., 2004, Geochronology of the Midas Low-Sulfidation Epithermal Gold-Silver Deposit, Elko County, Nevada: Economic Geology, v. 99, pp. 1665–1686.

Ponce, D.A., and Glen, J.M.G, 2002, Relationship of epithermal gold deposits to large-scale fractures in northern Nevada: Economic Geology, v. 97, no. 1, p. 3-9.

Wallace, A.R., 1993, Geologic map of the Snowstorm Mountains and vicinity, Elko and Humboldt Counties, Nevada: U.S. Geological Survey, Miscellaneous Investigations Series Map I-2394, scale 1:50000.

Wallace, A.R., and John, D.A., 1998, New studies on Tertiary volcanic rocks and mineral deposits, northern Nevada rift, in Tosdal, R.M., ed., Contributions to the gold metallogeny of northern Nevada: U.S. Geological Survey Open-File Report 98-338, p. 264-278.

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