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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Geologic Implications of a Geo-Chemical Study of Three Two-Mica Granites in Southern Arizona

Arnold, Andrew Herbert January 1986 (has links)
The biotite + muscovite ± garnet-bearing Texas Canyon (TC), Presumido Peak (PP), and Gunnery Range (GR) granites are members of an enigmatic suite of Eocene age granites in southern Arizona. The late orogenic granites intrude Precambrian through Jurassic metasediments and metavolcanics. The major and minor element geochemistry of the high silica, weakly peraluminous granites is rather uniform. However, trace element concentrations, REE patterns, and isotopic compositions imply gross similarities between the TC and GR granites when both are compared to the PP granite. The TC and GR granites were derived from a depleted Precambrian lower crustal source area with low Rb/Sr, while the PP granite was the result of anatectic melting of an enriched Precambrian mid-to-upper crustal source. The PP granite is an integral part of a metamorphic core complex, and this tectonic setting accounts for the geochemical differences between it and both the TC and GR granites.
2

Chemical ratios of Laramide igneous rocks and their relation to a paleosubduction zone under Arizona

Dewhurst, JoAnna, 1944- January 1976 (has links)
No description available.
3

A geochemical comparison of some barren and mineralized igneous complexes of southern Arizona

Bolin, David Samuel, 1941- January 1976 (has links)
No description available.
4

The geology and geochemistry of beryllium in southern Arizona

Balla, John Coleman, 1936- January 1962 (has links)
No description available.
5

Geochemical investigation of the Del Bac Hills volcanics, Pima County, Arizona

Percious, Judith K., Percious, Judith K. January 1968 (has links)
The Del Bac Hills are a northeast-trending chain composed of mid-Tertiary Turkey Track porphyry dikes and flows, overlain by potassic basaltic andesites intercalated with sediments. These hills are considered the southernmost extension of the Tucson Mountains and lie along a northeast-trending basement scarp which extends across the Tucson Basin. Turkey Track porphyry intrudes the San Xavier conglomerate as two parallel dikes, closely associated in time but with different magnetic orientations. Potassium-argon dating of a flow associated with the older dike yielded a mean of 26.8 m.y. for plagioclase phenocrysts and groundmass. Plagioclase of the younger dike sampled 50 feet from the contact with the San Xavier conglomerate and at a depth of approximately 200 feet yielded an anomalous age of 46.4 m.y., representing 0.29 x 10^-10 moles per gram excess Ar4° in comparison with the extrusive. The 21 basaltic andesite flows are essentially contemporaneous at 24-25 m.y. Tight grouping of K/Rb and Rb/Sr for the basaltic andesites confirms the field inference of two separate sources. Specific gravity and initial Sr^87/Sr^86 determinations for the porphyry and basaltic andesites do not preclude a comagmatic origin for the two rock types. Post-extrusive faulting along three principal directions has established the present configuration of the hills.
6

A GEOCHEMICAL STUDY OF ALTERATION AND MINERALIZATION IN THE WALLAPAI MINING DISTRICT, MOHAVE COUNTY, ARIZONA (MINERAL PARK, FLUID INCLUSIONS, SULFUR ISOTOPES).

Lang, James Robert, 1961- January 1986 (has links)
No description available.
7

Tungsten occurrences in Arizona and their possible relationship to metallogenesis

Myers, Genne Marie, Myers, Genne Marie January 1983 (has links)
No description available.
8

The petrology and geochemistry of the Cienega Falls diabase sill, Salt River Canyon area, Gila County, Arizona

Schofield, Richard Edward, 1946- January 1976 (has links)
No description available.
9

Geochemistry and petrology of the ash flows of Chiricahua National Monument, Arizona, and their relation to the Turkey Creek caldera

Latta, John Stephen January 1983 (has links)
No description available.
10

Trace element and stable isotope geochemistry and diagenesis in Cenozoic mineta formation limestones, Southeastern Arizona

Plouff, Michael Thomas January 1983 (has links)
No description available.

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