Global ETD Search
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Showing 1 to 15 of 15 for “"quartz diorite"”.
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Petrogenesis of the Moosehorn igneous complex, Maine
… in composition from olivine norite through quartz diorite and granodiorite. Partially crystallized mafic magmas are often intruded by slightly peraluminous biotite ± hornblende granites as demonstrated by the occurrence of a wide range of enclave-host relationships. The igneous complexes are …
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Geochemistry of igneous rocks from the southern coast belt plutonic complex, southwestern British Columbia
… ranging in composition from granite, tonalite, quartz diorite, diorite to gabbro, with an average composition of quartz diorite. Subordinate Permian to Quaternary metamorphic and volcanic rocks make up the remainder of the southern CPC. Nd, Sr, and Pb isotopic data suggest that plutonic and …
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A contribution to the study of older granites in the Nigerian Precambrian with special reference to the Tegina granite
… granite, a porphyritic biotite granite. Granodiorite and quartz-diorite in it represent local or marginal contamination. (2) Similar rocks are developed in the zone of banded foliation. In addition, there are remnant bands of granodiorite providing evidence that the 'granite' was formed as …
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Petrogenesis of the phase 1 gabbro-diorite of the Miocene Mt Perkins Pluton, northwest Arizona: Implications for the role of mantle-derived mafic magmas in calc-alkaline magma evolution
… of Precambrian orthogneiss. Phase 1 is a gabbro-diorite containing four rock groups: olivine-clinopyroxene cumulates, hornblende-plagioclase cumulates, homblende gabbro, and quartz diorite. Stage one of phases 2 and 3 evolved by a process of fractional crystallization of an asthenospheric mantle …
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Petrology of the Numabin Bay intrusions, Reindeer Lake, Saskatchewan
… Precambrian granitic pluton, consisting of quartz diorite, granodiorite, and quartz monzonite, is consistent with the results of petrographic and structural studies. Petrographic modal analyses and accurate plagioclase determinations by the Rittman Zone Method and X-ray diffraction revealed: …
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The Foyers Granitic Complex and its aureole
… Survey Sheet 73E. The complex contains quartz diorite cut by quartz monzodiorite in the north, granodiorite in the south, and cross cutting adamellite stocks throughout the pluton. These units are the products of a differentiating magma body at depth. A north easterly trending suite of …
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Evolution of chemical composition along river drainage networks
… a change in bedrock composition from intrusive quartz diorite (upstream) to volcaniclasitc material (downstream). Overall, after sea-salt correction, most solutes decreased consistently with distance downstream. The silica to alumina ratio, however, changed sharply with changes in the underlying …
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Iron-Carbon Associations In Tropical Soils Of The Luquillo Critical Zone
… by highly-weathered, volcaniclastic Oxisols or quartz diorite-derived Inceptisols, producing an experimental gradient of iron content and speciation. To characterize the interactions between inherently heterogeneous soil C and often amorphous mineralogy, this dissertation paired high-resolution …
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Strain Analysis Across the Margins of the Elkahatchee and Coley Creek Plutons, Alabama Eastern Blue Ridge: Implications for the Alexander City Fault
… plutons. Two of these plutons, the Elkahatchee Quartz Diorite and Coley Creek orthogneiss exhibit zones of high strain, evidenced by mylonitic fabrics, ductile deformation of feldspar grains, grain size reduction, and changes in mica content at their margins. Geologic mapping in the vicinity of …
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Geology of the Snip Mine, and its relationship to the magmatic and deformational history of the Johnny Mountain area, northwestern British Columbia
… by, wall rock replacement; and (iii) dilatant quartz veins and (iv) dilatant pyrite-pyrrhotite sulphide veins. Alteration comprises pale calcite-K-feldspar-silica envelopes surrounding black biotite envelopes adjacent to the veins. A post-ore biotite-altered mafic dyke intrudes the zone. …
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Structural evolution of crystalline lower plate rocks, Central Sacramento Mountains, Southeastern California
… event (D1), is the predominant fabric in the quartzofeldspathic country rock (grey gneiss). The second deformational event (D2) produced a variably developed greenschist facies-grade fabric (Sm) in the grey gneiss and in two post-D1 plutonic suites. Both of these plutons are thought to be …
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Magmatism, Deformation And Mesothermal Metasomatism: Interpretation Of Aluminosilicate Mineral Assemblages In The Cargo Muchacho Mountains, Southeastern California
… to top, they are: (a) the Feldspar Zone, with quartz-oligoclase-K-feldspar-biotite-epidote-magnetite, (b) the Muscovite Zone, with quartz-muscovite-biotite-magnetite-tourmaline-apatite, and (c) the Kyanite Zone, with quartz-kyanite-muscovite-magnetite-rutile-tourmaline-apatite (with or without …
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The geology and geochemistry of the Omai goldfield, Guyana
… primary mineralisation is centred on a high-AI, quartz diorite-tonalite boss (the Omai Stock), where wall-rock alteration is dominated by a hydrothermal sericite-carbonate assemblage. The primary ore package of Au-W-Te-S mineralisation is contained in a series of narrow (1-5cm), quartzcarbonate …
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The structure and metamorphism of the Santa Marta area, Colombia, South America
… The Concha Formation is composed of fine-grained quartzo-feldspathic schists and massive chloritic feldspathic greenschists, the former characteristically displaying a crenulation foliation in varying degrees of development. The Concha Formation has suffered retrograde metamorphism under high PCO2 …
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Petrologic Significance of Multiple Magmas in the Quottoon Igneous Complex, NW British Columbia and SE Alaska
The quartz dioritic Quottoon Igneous Complex (QIC) is a major Paleogene (65-56 Ma) magmatic body in NW British Columbia and SE Alaska that was emplaced along the Coast shear zone (CSZ). The QIC contains two different igneous suites that provide information about source regions, magmatic processes …