The geology at Pulver Gulch is unlike the surrounding area. The sediments at Pulver Gulch contain more calcium carbonate, from impure and muddy limestones, than the surrounding ocean sediments that formed the Puma Hills. These calcareous sediments were heated, compressed, and transformed into calcium silicate rocks that host a group of interesting metamorphic minerals that include scheelite, vesuvianite, wollastonite, grossular garnet, and diopside. The Pulver Gulch prospect’s exploratory dump is an excellent place to search for these metamorphic minerals.
|Figure 1. Scheelite crystals and muscovite mica showing |
fluorescence under ultraviolet radiation. Image courtesy of Wikipedia.
|Figure 2. Vesuvianite crystal. |
Image courtesy of the CSMS blog by Mike Nelson.
|Figure 3. Wollastonite with diopside (green), garnet (red) and vesuvianite (dark brown) |
from the Stanislaw mine near Szklarska Poreba, Izerskie Mountains,
Lower Silesia, Poland. Image courtesy of Wikipedia.
|Figure 4. Garnet crystals from the Jeffery Mine, Quebec.|
Image courtesy of the Canada. Bureau of Mines, specimens C-01687.
|Figure 5. Diopside crystal from De Kalb, New York.|
Image courtesy of Wikipedia.
Chesterman, Charles, 1978, The Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York.
Chronic, Halka, 1980, Roadside Geology of Colorado, Mountain Press Publishing Co, Missoula.
Mineral Galleries, World Wide Web homepage URL: http://mineral.galleries.com/minerals/silicate/vesuvian/vesuvian.htm
Wobus, R.A., 1997 (Williams College) personal communication.