Global ETD Search

1	A Kimberlite, Its Mineralogy, and Implications Convery, Thie 03 May 1990 (has links) <p> Kimberlite diatremes from a single genetic source were examined. Macrocryst and groundmass constituents were identified, as well as their alteration products. It was hypothesized that carbon dioxide and water vapour were present at the time of formation. Limestone inclusions and peridotite xenoliths were examined, as well as fabrics within the xenoliths. It was concluded that water is present in the upper mantle. Ilmenite nodules were determined to be phenocrysts, as opposed to xenocrysts. A paragenetic sequence for the kimberlite was resolved. Ilmenite was classified as the best indicator mineral for exploration purposes.</p> / Thesis / Bachelor of Science (BSc)
2	Caractérisation géochimique des volcanites et d'une cheminée d'altération dans la partie ouest du bloc de Powell, Rouyn-Noranda, Québec / L'Heureux, Marc. January 1992 (has links) Mémoire (M.Sc.T.)-- Université du Québec à Chicoutimi, 1992. / Bibliogr.: f. 70-77. Document électronique également accessible en format PDF. CaQCU
3	The petrology, petrography and geochemistry of anomalous borehole core sequences in the Highveld coalfield, South Africa : a case study for diatreme activity 12 November 2012 (has links) M.Sc. (Geology) / Three anomalous borehole core sequences from the north eastern Karoo Basin are examined. The boreholes are located up to 30 km from each other and are lithostratigraphically completely atypical for the Vryheid Formation, Ecca Group, Karoo Supergroup. The lithologies of the three boreholes are intensely brecciated for the most part, while all of the surrounding boreholes reveal normal stratigraphy; their sedimentary strata are normally horizontal with no faulting present. The only known disturbances to the Vryheid Formation in the study area are the occurrence of intrusive mafic dolerite sills and dykes, which are known to have been contemporaneous with and immediately following the eruption of the Drakensburg Group basaltic lavas. The borehole core lithologies are described in detail with reference to their textural, mineralogical and petrographic characteristics. Mineral and bulk rock chemical data are presented. Several modes of origin of the brecciated core sequences are considered, with the primary hypothesis that the brecciation is due to diatreme activity. A review of diatremes and their mode of emplacement is proposed with reference to their occurrence within the Karoo Igneous Province, as some diatremes in the Karoo are associated with dolerite sill emplacement. The isolated occurrences, lithologies, petrography, alteration and geochemistry of the sequences are used to argue that the Vryheid Formation, intersected in the form of the three anomalous boreholes, was disturbed by diatreme activity, which are genetically related to the late dolerite sill emplacement into the Karoo Supergroup rocks. Borings - South Africa - Highveld Region Breccia - South Africa - Highveld Region Geology, Stratigraphic
4	Preliminary Investigations of the Hydrologic Properties of Diatremes in the Hopi Buttes, Arizona Scott, Kenneth C., Edmonds, R. J., Montgomery, E. L. 20 April 1974 (has links) From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, Arizona / Diatremes of Late Pliocene age in the Hopi Buttes area of Arizona are becoming increasingly important sources of groundwater to the Indian nations. These volcanic vent structures are prime sources of groundwater because sedimentary formations in the Hopi Buttes area yield only limited amounts of water or yield poor quality water. Diatremes act as traps for groundwater and some have yielded moderate amounts of good quality water to wells. Surface geologic investigations and analysis of drillers' logs indicate that structural relationships and diatreme lithology provide a means to project the hydrologic properties of the vent. Diatremes most suitable for groundwater development should have a diameter greater than one half mile, should contain volcanic tuff and breccia at its center, and should be fractured from collapse. Lava flows covering diatremes reduce recharge from sheet wash or from ephemeral stream flow. Data from geomagnetic and gravity surveys will be analyzed to determine its suitability for predicting subsurface size, shape, and lithology of the diatreme. The integration of geophysical and surface geologic data will reveal the total geometry of the structure enabling the most accurate appraisal of the hydrologic properties of the diatreme. Hydrology -- Arizona. Water resources development -- Arizona. Hydrology -- Southwestern states. Water supply Groundwater basins Water wells Hydrologic properties Groundwater availability Arizona Petrology Permeability Soil properties Water properties Water resources Recharge Water quality Groundwater mining Aquifers Groundwater Aquifer characteristics Water sources Water yield Hydrogeology Water storage Igneous rocks Diatremes Hopi buttes (ariz)

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