Barium in granitoid rocks of the Basin and Range Province of Nevada, Utah, California, and Arizona
Explore the source record for details and available documents.
Open-File Report↗
Geology topics
Harry J. Rose
Publications and source records attributed to Harry J. Rose.
The chemistry of five accessory rock-forming apatites
Chemical and physical data are given for five samples of rock-forming apatite from diverse geologic environments in Nevada and Colorado. Four of these apatites contain rare-earth assemblages in which the cerium group is well represented but the yttrium group predominates. The fifth apatite contains a highly fractionated assemblage of the lighter (cerium group) rare earths similar to the assemblage typical of alkulic rocks.
Nevada, Colorado↗
Fractionation of minor elements between galena and sphalerite, Darwin lead-silver-zinc mine, Inyo County, California and its significance in geothermometry
Minor element abundances were determined for galena and sphalerite from the Darwin mine, Inyo County, California. The temperature of deposition was calculated from the distribution coefficients determined experimentally by Bethke and Barton (1971) for cadmium and manganese in coexisting galena and sphalerite. The fractionation of cadmium between coexisting sphalerite and galena indicates a temperature of deposition of 416 degrees C+ or -20 degrees , the fractionation of manganese between the same mineral pair a temperature of 377 degrees C+ or -32 degrees . The fractionation of selenium gave unreasonably high temperatures. Three pairs gave temperatures between 568 degrees and 625 degrees C, the fourth pair a temperature of 889 degrees C. The reason for this descrepancy is not known.
California↗
Boulder Creek batholith, Colorado part I: Allanite and its bearing upon age patterns
Allanite is abundant and commonly attains unusually large size as a late-replacement mineral in: (1) the comagnatic rocks of the Precambrian Boulder Creek batholith; (2) associated amphibolite xenoliths and related hybrid rocks; and (3) distinctly younger intrusions of Silver Plume Granite that cut the complex. Allanite porphyroblasts develop by replacement of biotite, probably in the presence of emanations from the rare earth-rich and thorium-rich Silver Plume Granite. The largest allanite crystals are made up of nearly isotropic (metamict) cores and birefringent (recrystallized) rims. Smaller crystals are made up exclusively of birefringent material. The maximum birefringence is shown to be that expectable in allanite of Late Cretaceous to early Tertiary age. As plotted on maps, the birefringence increases, and the thorium and uranium contents of the allanite decrease toward a Laramide stock. The variation in birefringence is, therefore, largely relatable to variations in the post-Laramide radiation dosage brought about by differences in the amounts of uranium and thorium lost during recrystallization. The recrystallized allanite is itself partly replaced by epidote which characteristically occurs as a border between allanite and biotite. Total rare-earth oxides for the eight samples of allanite analyzed range from 17.5 to 21.3 percent by weight. In 13 samples, thorium ranged from 0.50 to 1.14 percent by weight, and uranium from 54 to 158 parts pparts per million. Ranges in optical measurements for 20 samples using the spindle stage are: Nα = 1.719–1.759, Nβ = 1.731-1.774, N γ = 1.741–1.784, birefringence = 0.020–0.032, 2V X (calc.) 70°–84°. Ranges for unit-cell data obtained on 8 samples are: a = 8.948–8.985Å, b = 5.721-5.763Å, c = 10.184–10.240Å, β = 115°7.50′–115°25.89′ and volume = 473.02–478.43Å 3 . The average value for the ratio a:b:c = 1.561:1:1.778.
Colorado↗
Sulfides associated with the Salton Sea geothermal brine
Concentrated saline brine tapped by a deep well drilled for geothermal power near the Salton Sea, California, deposited metal-rich siliceous scale at the rate of 2 to 3 tons per month. The iron-rich opaline scale contains an average of 20% Cu and up to 6% Ag present in bornite, digenite, chalcopyrite, a new dense polymorph of chalcocite, stromeyerite, and native silver.The brines are in equilibrium with an assemblage of sulfide minerals in the reservoir rocks. Sphalerite containing 16.6 mol % FeS is in equilibrium with the brine in which the activity of sulfur (a (sub s 2 ) ) is estimated at 10 (super -10.2) at 325 degrees C. This is in good agreement with the projected high-temperature data of Barton and Toulmin (2) for the system Fe-Zn-S. Other sulfides identified in the reservoir rocks are pyrite, pyrrhotite, chalcopyrite, and galena.The heavy metals in solution are apparently derived from the sediments of the brine reservoir, being released from the silicate minerals in which they occur in trace amounts, as metamorphism of the sediment proceeds. Although the total of the heavy metals in solution greatly exceeds the sulfur, on a molal basis, the brine is saturated with respect to sulfide components and addition of more sulfide ion would only cause precipitation of sulfides.
California↗