Tuesday, May 1, 2012

Early Morning View of the Midas Trough and Jake Creek Mountain

Just a quick post showing a photo I took about two weeks ago at 5:50 am, on my early morning ride to work. We're looking easterly at a broad, generally flat-topped sloping part of the southern Snowstorm Mountains. The entire mesa-like, gently north-dipping hill may be called Jake Creek Mountain, or perhaps only its highest peak, barely visible from this angle, is called Jake Creek Mountain. Part of the abrupt slope to the south is called the Owyhee Bluffs.

The low area immediately south (right) of the central flat-topped mesa or mountain is at least locally called the Midas Trough. Tectonically, the trough is a somewhat complex graben, sharp edged on its north and south sides, bounded by ENE-trending faults (MSRMaps topography showing the Midas Trough; also see this Google Maps image). References to the Midas Trough are mostly found in the gold exploration literature and on related company websites, but was referenced in the tectonic literature at least as early as 1980. I also found a Santa Fe Pacific Mining Company reference to the fault along the north edge of the Midas Trough, which was called the "Midas road fault," presumably because it more or less follows the graveled road to the tiny berg of Midas (the date on the map says 2005, but mapping was done in 1988-1991, and Santa Fe Pacific Gold was bought by the "Evil Empire," Newmont Mining, in 1997). I'll visit Midas (the town) someday, and report back about whether Kirby's Midas Bar is still in business, the way it was during the boom days of the 1980s.

North (left) of the mesa-like Jake Creek Mountain, the next low spot is referred to as the Jake Creek graben, at least in the report accompanying Santa Fe's map. Farther north, the next hill -- also part of the Snowstorm Mountains, which trend NNW parallel to the Northern Nevada Rift, even though its southern sub-parts trend ENE parallel to the Midas Trough -- is called Kelly Creek Mountain (or at least its high point is called that; I can't get on MSRMaps at the moment to check the old topos for names).

A couple references:
Laravie, J.A., 2005, Geologic Map of the Kelly Creek Area, Humboldt, Elko, and Lander Counties, Nevada: Nevada Bureau of Mines and Geology Open-File Report 05-1 -- Text, Plate 1 with the Midas road fault, Plate 2, with a more readable map explanation.

Zoback, Mary Lou, and Zoback, Mark D., 1980, Faulting Patterns in North-Central Nevada and Strength of the Crust: Journal of Geophysical Research, v. 85, p. 275-284.

Location shown below is the west end of the Midas Trough.

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