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Thesis (Ph. D.)--University of Texas at Austin, 2003. / Supervisor: Larry W. Lake. Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1988. / Includes bibliographical references (leaves 159-162).

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1910. / L. J. Porri determined to be Louis Joseph Porri and J. L. Pickering determined to be John Lyle Pickering from "Forty-First Annual Catalogue. School of Mines and Metallurgy, University of Missouri". The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed February 23, 2009)

Dissolution rates of hornblende and tremolite were studied in constant pH batch experiments over the pH range 4-6, in order to understand the acid neutralizing role of hornblende in watersheds with low alkalinity. Hornblende and tremolite exhibit linear dissolution kinetics within one or two days after the onset of weathering. During the first 80-100 hours of weathering, base cations are released preferentially to silica in both minerals. During this period a leached surface layer similar in structure to the original material, but altered in composition is believed to be formed. Release rates of Si, Ca, Na, and Mg from hornblende exhibit weak fractional dependence on pH: d[Mg] /dt = k₁[H⁺] 0.13, d[Ca] /dt = k₁[H⁺] 0.065, d[Na] /dt = k₁[H⁺] 0.17, and d[Si] /dt = k₁[H⁺] 0.045. As a result, it is believed that, for large and transient influxes of acidified water, hornblende is not an important pH buffer. Because of rapid dissolution rates, however, hornblende could be an important source of acid neutralizing capacity.

Thesis (Ph.D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 200-207).

Thesis (Ph. D.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

No description available.

The control exerted by underlying geological formations, topography and time in governing physico-chemical variability of shallow waterbodies is documented for Schefferville. Nouveau-Quebec and Igloolik Island, N.W.T. / The highly resistant siliceous bedrock of the Labrador Trough in the Schefferville area produced very dilute surface waters with more or less equivalent concentrations of major cations. Dolomitic limestone and dolostone on Igloolik Island resulted in highly mineralized surface waters dominated by Ca$ sp{2+}$, Mg$ sp{2+}$ and HCO$ sb3 sp-$, with contributions by Na$ sp+$ and Cl$ sp-$ increasing with coastal proximity. / Sediments from the Schefferville area possessed low concentrations of Ca and Mg indicative of noncarbonate bearing substrate, contrasting to the calcareous nature of the sediments from Igloolik Island. Sediment concentrations of Al, Fe and Mn from the Schefferville area were elevated compared to sediment concentrations on Igloolik Island. The disparity in trace metal concentrations in sediments between the two study areas is attributed to the enrichment of these elements in the Labrador Trough, as well as the general trace metal dilution encountered in limestone and dolostone. / Principal Component Analysis with Varimax Rotation for surface waters of Igloolik Island revealed four factors accounting for 98% of the total variance confirming controls exerted by sea-salt spray and lithological substrate in moderating surface water chemistry. Differential rates of weathering at certain sites on Igloolik Island are suggested by dissimilar factor loading scores.

No description available.