Cal Poly Geology Club Death Valley Field Trip â 2004

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• Stirling Quartzite - Pale gray, medium-to-coarse-grained sandstone(orthoquartzite), locally conglomeritic.• Johnnie Formation - Greenish-gray, pelitic schists.• Kingston Peak Formation - Upper member is a conglomerate with clasts ofquartzite and marble in a dark fine-grained groundmass. Lower member is peliticschist, generally silverish in color with a bright luster.• Beck Spring Dolomite - Pale white, gray or cream marble.• Crystal Spring Formation - Upper member is a pelitic schist and micaeousquartzite with lesser marble and amphibolite,; Middle member is mostly palemarble and interlayered schist; Lower member is pelitic schist with abundantamphibolite (diabase), layers and minor carbonate.In the vicinity of the Keane Wonder mine the dominant rocks are middle and lowerCrystal Spring Formation with marble, pelitic schist and amphibolite, common. Most ofthe central portion of the southern flank of the Funeral Mountains is bounded by theKeane Wonder fault. The fault, which is poorly exposed, dips 20° to the southwest.Proterozoic and Paleozoic rocks lie above the fault, while folded and stronglymetamorphosed Proterozoic strata lie beneath the fault plane.The gold ore occurs in two discontinuous, lenticular quartz veins which appear to followbedding planes, particularly the contact between marble and amphibolite; the latter themetamorphic equivalent of diabase. The quartz veins can be traced for 500 meters alongtheir N 25° W strike. The veins dip 20° E and vary in thickness from 2 to 8 meters. Oreminerals include free gold, minor pyrite and galena. Iron-staining is common, anindication of near surface oxidation of pyrite to hydrated iron oxides.Ore grades are reported to have been about .25 oz/ton and total production from the 1908-1916 period about 35,000 ounces of gold. The development consisted of a 75 meter deepshaft and over 2000 meters of underground workings, most of which are nowinaccessible. There has been no activity on the property since it was abandoned in 1916,but rumored sampling by the Park Service in the 1980s indicates there is significantrecoverable gold remaining in the mine dumps.
Harmony Borax Works – Twenty Mule TeamsThe first form of borax to be found in Death Valley was white crystalline ulexite called“cottonball”, which encrusted the ancient Lake Manly. Cottonball of this kind had beenfound earlier at Columbus Marsh and at Teel’s Marsh, in western Nevada.The first man to try to market Death Valley cottonball was an unsuccessful goldprospector named Daunet. In 1875 he could interest no one in his discovery. Fate madehim six years too early.In 1881 Aaron Winters, who lived in Ash Meadows with his wife, Rosie, offered anight’s lodging to a stranger, Henry Spiller, who was prospecting through the desert. Hishospitality was well rewarded. The stranger spoke of the growing interest in the mineralborax and showed him samples of cottonball. One look told Winters that he saw the samecrystals every day, covering acre upon acre of the floor of Death Valley.The next morning, as soon as his visitor left, Winters rode off to the Valley, scooped up abagful of cottonball and rode back to Ash Meadows. The stranger had told him about thetest for borax: pour alcohol and sulfuric acid over the ore and ignite it. If it burns green,it’s borax. At sundown, Aaron and Rosie tried the test on the bagful of sample: “Sheburns green, Rosie”, shouted Aaron, “We’re rich, by God!” And they were. Winters soldhis Death Valley claims to William Tell Coleman, a prominent San Francisco financierfor $20,000.Word of the Valley’s cottonball quickly spread. Daunet came back in 1882 and set up theEagle Borax Works, but quit the business when he found that borax could not beprocessed by simple recrystallization during the intense summer heat. By the timeoperations could resume in the fall, the price of borax had fallen and he was never able tomake the operation profitable.In 1882 Coleman began construction of theHarmony Borax Works. In 1883 he hiredChinese laborers to scrape borates from theancient lake bed for $1.50 per day. In fulloperation, the Harmony Borax Worksemployed forty men. "Cotton ball", an oremade up of the borate minerals ulexite andproberite, was then dissolved in boilingwater. As the solution cooled, borax wasprecipitated. The hardy workers (notice noChinese labors in the photo to the right)produced three tons of borax daily. Findingthat summer processing in the Valley was indeed impossible, he built the AmargosaBorax Works near Shoshone, where the summers were cooler. The ruined remains ofthese three early borax plants still stand in the desert. The borax was hauled to the nearestrailroad by the use of Twenty Mule Teams hitched to ponderous wagons. Coleman was
Page 1 and 2: Cal Poly Geology ClubDeath Valley F
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Page 7 and 8: MileageDeath Valley Field Trip Road
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Page 34 and 35: War Eagle MineThe War Eagle Mine is
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Cal Poly Geology Club Death Valley Field Trip â 2004

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Cal Poly Geology Club Death Valley Field Trip â 2004