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J. Haffty

Publications and source records attributed to J. Haffty.

5 recordsLinked to original sources
USGS1985

Characterization of the Sukinda and Nausahi ultramafic complexes, Orissa, India by platinum-group element geochemistry

Samples of 20 chromitite, 14 ultramafic and mafic rock, and 9 laterite and soil samples from the Precambrian Sukinda and Nausahi ultramafic complexes, Orissa, India were analyzed for platinum-group elements (PGE). The maximum concentrations are: palladium, 13 parts per billion (ppb); platinum, 120 ppb; rhodium, 21 ppb; iridium, 210 ppb; and ruthenium, 630 ppb. Comparison of chondrite-normalized ratios of PGE for the chromitite samples of lower Proterozoic to Archean age with similar data from Paleozoic and Mesozoic ophiolite complexes strongly implies that these complexes represent Precambrian analogs of ophiolite complexes. This finding is consistent with the geology and petrology of the Indian complexes and suggests that plate-tectonic and ocean basin development models probably apply to some parts of Precambrian shield areas.

Precambrian Research↗
USGS1983

Platinum-group elements in rocks from the voikar-syninsky ophiolite complex, Polar Urals, U.S.S.R.

Analyses of platinum-group elements (PGE) in rocks collected from the Voikar-Syninsky ophiolite in the Polar Urals suggest that the distribution and geochemistry of PGE in this Paleozoic ophiolite are similar to those in Mesozoic ophiolites from elsewhere. Chondrite-normalized PGE patterns for chromitite, the tectonite unit, and ultramafic and mafic cumulate unit have negative slopes. These results are similar to those found for chromitites from other ophiolites; stratiform chromities show positive slopes. If the magmas that form both types of chromitite originate from similar mantle source material with respect to PGE content, the processes involved must be quite different. However, the distinct chondrite-normalized PGE patterns may reflect differing source materials. ?? 1983 Springer-Verlag.

Mineralium Deposita↗
USGS1982

Palladium, platinum, rhodium, ruthenium, and iridium in chromitites from the Massif du Sud and Tiebaghi Massif, New Caledonia

Massive and disseminated podiform chromitite from 43 mines and other occurrences in the Massif du Sud and Tiebaghi Massif, both ophiolites, in New Caledonia contain up to 9 ppb Pd, up to 45 ppb Pt, up to 31 ppb Rh, up to 410 ppb Ir, and up to 1,130 ppb Ru. The chromitites are strongly depleted in Pt and Pd and mildly depleted in Ir and Ru with respect to an average chondrite composition, as are podiform chromitites from Oman, Turkey, Greece, and northern California. Stratiform chromitites from the Stillwater Complex, Montana, and the Bushveld Complex, South Africa, show inverse patterns of enrichment and depletion. These patterns suggest that either chromitite from ophiolites represents mantle rocks depleted in Pt and Pd or that the magmas that formed the ophiolites were depleted in Pt and Pd, or that the process of forming the chromitite involved the concentration of Os and Ir from a magma. The relatively high contents of Ir and Ru in the New Caledonian chromitite suggest the potential for the occurrence of placers that contain concentrations of Os-Ir alloys.

Economic Geology↗
USGS1963

Implications of the minor element content of some major streams of the world

Of 15 or more minor elements in the world's principal river waters only aluminum, iron, manganese, barium and strontium range much over 100 μg l "> 100 μgl . (parts per billion). Most minor elements range at or below 100 μg 1 "> 100 μg1 . and have median (or middle) values of 10 micrograms per liter or less. Significant areal differences in minor element content are found in the river waters. For example, Atlantic Coastal river waters in the aggregate are slightly more enriched in concentrations of silver, chromium, manganese, molybdenum, nickel, strontium and titanium, and slightly deficient in barium and lithium when compared with median values for North America. Median values of ratios Ba Sr "> BaSr , Ni Cr "> NiCr and Ni Cu "> NiCu are reasonably consistent (within a factor of two) in principal drainage from North America. Noteworthy are consistent median ratios of Ni Cu "> NiCu for large rivers of United States, but the ratio tends to be slightly greater in global northern latitudes than in southern latitudes. Median values for aluminum, barium, copper, lead, molybdenum and silver in North American runoff are of the same order as published world averages for ocean water. Hydrologic and geochemical aspects of continental runoff are strongly implied in observations of minor element content of large rivers. Evidence to date is that median values of Ba Sr ratios "> BaSr ratios are relatively uniform in global river waters. There is real danger in oversimplifying chemical systems in broad assessments of lower reaches of large drainage basins because individual hydrologic and chemical events upstream are largely obscured.

Geochimica et Cosmochimica Acta↗