I scored a couple weeks of contract work placing placer claims in the remote Snake Valley of western Utah with a friend of mine. Despite the remoteness, it turned out I had been within 30 miles of the site before (Gandy Warm Springs is not too far away). The site was actually really interesting as far as placer sites go. At times during the late Pleistocene the valley was filled to varying degrees by the voluminous ancient Lake Bonneville which had entire mountain ranges as islands (the Great Salt Lake and Bonneville salt flats would have comprised only a small portion of the lake's extent). Alluvial fans emptying the Deep Creek Range on the west side of the valley contain a higher percentage of detrital magnetite (source of iron), monazite (source of rare earth elements) and other heavy minerals sourced from a granitic intrusion the catchments transect. These alluvial fans interacted with the paleo-lakes to create deltas, sea cliffs, beaches and sandspits. In some cases the sediments were reworked to a considerable degree along the shore, creating rich black sand deposits. The beauty of this deposit is that the magnetite can be readily separated using a cheap and easy sieve and magnetic separation system and since no byproducts are produced remediating the site should be rather easy.
It normally would have been an easy job but it was the dead of winter.
Snow coverage was more than we hoped and all north-facing slopes were
thickly coated. The ground was frozen to depths of 10 inches which was
difficult to break through. It was hard work. Highs were in the 40s,
lows in the 10-20s at night made for cold camping. Despite the
difficulties we managed to keep efficiency high and finished just in
time (two days after we finished the whole area was covered in snow all
over again). It was good to have the work. The site was really
interesting. Thanks to Ryan.
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