Thesis--Wisconsin. / Digitized and made available by the University of Wisconsin Digital Collections Center as part of Minds@UW. Description based on print version record. WU Includes bibliographical references (leaves 86-91).

Thesis--Wisconsin. / Includes bibliographical references (leaves 86-91).

Thesis (M.A.)--University of Texas at Austin, 1981. / Three maps on 3 folded leaves in pocket. Summary in English. Translation of: Skarn and epithermal vein mineralization in the San Carlos Caldera region, northeastern Chihuahua, Mexico. Includes bibliographical references (p. 63-66).

No description available.

Thesis (Ph. D.)--University of Wisconsin. / "From Bulletin no. IV, Wisconsin geological and natural history survey."

Thesis (M.A.)--University of Texas at Austin, 1981. / Three maps on 3 folded leaves in pocket. Summary in English. Translation of: Skarn and epithermal vein mineralization in the San Carlos Caldera region, northeastern Chihuahua, Mexico. Includes bibliographical references (p. 63-66).

A description of the geochemistry of tungsten is given. The geochemical properties of tungsten have a strong influence on its mineralogy, distribution and abundance in crustal rocks and rock-forming minerals , and its migration/deposition within the ore-forming and supergene environments. The behaviour of tungsten during migration, from source to site of deposition, within the crust is discussed in some detail and environments considered favourable to the concentration of tungsten ore minerals are suggested. All major types of tungsten ore deposit are described with emphasis placed on those of greater economic importance. Characteristic features of each type of deposit are particularly emphasized in order to provide clear guidelines to exploration. Hydrothermal, pyrometasomatic and stratabound tungsten deposits present themselves, economically, as the most important exploration targets. The recently developed concept of syngenetic stratabound tungsten mineralisation is outlined. Exploration for deposits of this type should be aimed predominantly, but not exclusively, at volcano-sedimentary sequences of Lower Palaeozoic age, particularly within regions known to contain occurrences of Sb and Hg. Tungsten deposits commonly contain concentrations of one or more of the following metals: Sn, Sb, Bi, Mo, Au and Ag. The presence and possible extractive value of these metals, together with commonly associated metal impurities such as As, must always be taken into account in a feasibility study / Adobe Acrobat 9.53 Paper Capture Plug-in

The granitic rocks are subdivided into four series: tholeiitic, alkaline, calc-alkaline and mobilizates. These series can be formed from melting of mantle material (M-type granites) or from crustal rocks. There are granitic rocks formed from the mixing of these two magmas types. The rocks formed from crustal anatexis are subdivided into those formed from igneous rocks (I-type granites) and those formed from meta-sedimentary rocks (S-type granites). The former has similar characteristics to the mantle-derived granitoids. The mineral deposits related to igneous or mantle derived magma usually are Cu-Au, CUI Cu-Mo, Mo porphyries and have high oxygen fugacity and magnetic susceptibility (magnetite series). The Sn-W deposits usually are related to magma derived from meta-sedimentary or igneous rocks derived magma with low oxygen fugacity and magnetic susceptibility (ilmenite series). According to the tectonic setting, the granitoids rocks are classified as: Andino type, West Pacific type, Hercyno type, Caledonian type and Anorogenic (A-type granites).

Thesis (Ph. D.)--University of Adelaide, Dept. of Economic Geology, 1984. / Microfiche and maps (numbered 1-7) in pocket. Includes bibliographical references (6 unnumbered leaves ).

Thesis (B.Sc.(Hons.))--University of Adelaide, Dept. of Economic Geology, 1969. / Two folded maps in pocket on back cover. Includes bibliographical references (4 leaves).