<p> Chan and Riley (1967) developed a colorimetric method for the determination of tungsten in natural waters and silicate rocks. Applied to silicate rocks this method contains the following stages: evaporation of silica with hydrofluoric acid, co-precipitation of tungsten and some other elements, with hydrous manganese dioxide and cation-exchange separation of vanadium, molybdenum and tungsten. When applying this method on standard solutions and the new U.S.G.S. standard rocks, the results obtained are lower than those suggested by the authors. The results obtained recently with neutron activation analysis of the same standard rocks by Johansen and Steinnes (1970), although different from the results of the present work, also disagree with Chan and Riley. The method was abandoned since a tungsten loss is believed to occur throughout the procedure.</p> / Thesis / Master of Science (MSc)

<p> Granitic and associated metamorphic rocks of Precambrian age in southeastern Ontario, Canada have been studied in order to determine the relationship of K, Rb and Tl and their behaviour during the process of partial melting and magmatic differentiation and metasomatism. </p> <p> Analytical results for major elements and rubidium and thallium abundances for 52 samples are given. </p> <p> From the present data, it appears possible that the series of migmatite and granodiorite gneiss originated by partial melting of paragneiss, together with pink granite which developed by late magmatic processes from a granodiorite melt, as was proposed by Chesworth (1967). </p> <p> Consideration of the geochemical data shows that the principal aspects of the distribution of Rb and Tl during partial melting are controlled by the mineralogical composition of the residuum which remains after partial melting. If mica is present in the residuum a newly-formed melt could have higher or the same K/Rb, K/Tl and Rb/Tl ratios as the parent rock and thus the "classical rule" of lower K/Rb and K/Tl in the anatectic melt is not valid. </p> <p> Enrichment of Tl in rocks affected by metasomatic processes is demonstrated. The marked decrease of K/Tl and Rb/Tl in the contact rocks (calc-silicate marbles) is caused by stronger migration of Tl, relative to K and Rb, from the intruded pink granite. </p> <p> The high mobility of thallium compounds is an important factor in the distribution of Tl during metasomatic and magmatogenic processes. </p> / Thesis / Master of Science (MSc)

<p> An attempt has been made to estimate the abundance of trace and major constituents in the Precambrian surficial rocks in a large part (43,000 square miles) of the Red Lake - Lansdowne House area in northwestern Ontario. The area has an average composition which is close to that of granodiorite, more silicic than most estimates of crustal abundance, close to other estimates for continental shield areas, but possibly deficient in K2O relative to Poldervaart's (1955) estimate. The rocks of this area appear to be low in Be, Ti, V, Cu, Y, Sc and Zr, and high in Sr, relative to crustal abundances based on the proportion of exposed rocks on the surface of the continents (Turekian and Wedepohl, 1961). Analysis of variance techniques have detected significant regional variations of Cr, Mn, Sr and Ba. Significant variation exists between rock types for all trace elements analyzed except Cu.</p> / Thesis / Master of Science (MSc)

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No description available.

At the dawn of history, man used rocks for shelter, defense and places of worship. As he became more advanced, he evolved art forms from rock. In China and Japan rocks were used as sculpture with symbolic meaning over 2000 years ago. The English adapted Oriental ideas on the landscape uses of rocks to produce the typical English rock garden. In the United States, rocks were used very sparingly before 1900 as landscape enriching elements. During the 1920's the English rock garden became popular here, but soon lost its appeal. After World War II national interest was aroused in the Japanese usages of rocks. Rocks range in size from sand grains to mammoth boulders. They vary tremendously in size, color, texture, stratification and form. They have vast potential as landscape elements in residential, commercial, industrial, campus and highway landscapes, in parks and parking lots, and around public buildings. Naturally sculptured rocks have an aged appearance and a feeling of solidity that ideally qualify them as spatial and enriching elements in the landscape. Their beauty, symbolism, utility and generally low maintenance requirements adapt them to our modern way of life as long lasting, satisfying, usable art forms. In the landscape they may be used as ground covers, stepping stones, natural featured sculptures, retaining walls, space dividers, focal points, screens, in dry streams, in bodies of water, as complements for plant materials and in numerous other exciting ways. / M. S.

[Truncated abstract] Many researchers have proposed the use of silicate rock fertilizers (SRFs) as alternatives to chemical fertilizers. However, the application of SRFs in modern agricultural practices is limited due mainly to the slow release of plant-nutrient elements from SRFs and consequently many tonnes/ha of SRFs may need to be applied. Simple and inexpensive methods of modifying the physicochemical properties of SRFs are needed to improve the agronomic effectiveness of SRFs. This thesis is focused on the evaluation of high-energy milling to produce superfine particles to improve the effectiveness of mafic (basalt and dolerite) and felsic (gneiss and K-feldspar) rocks for use as fertilizers. The ground mafic rocks are for use as Ca and Mg fertilizers and the ground felsic rocks as K fertilizers. Laboratory and glasshouse experiments were conducted with several potential SRFs. In laboratory experiments, initially milled rocks (Ø< 250 μm for basalt, dolerite, and gneiss; Ø < 150 μm for K-feldspar) were further milled with a ball mill (Spex-8000) for 10, 30, 60, 90, and 120 min under dry and wet (rock/water ratio = 1/3) conditions. To investigate possible reaction between constituents, other subsamples of initially milled basalt, dolerite, and gneiss were added to reagent grade NaCl or KCl (4.5 g rock + 0.5 g NaCl or KCl) and milled for 120 min under dry and wet conditions. Basalt and dolerite were also mixed with K-feldspar at a ratio of 1 : 1 and milled for 120 min under dry and wet conditions. For use in the glasshouse experiment, the initially milled rocks were further milled with a vertical stirred ball mill for 1 h in a dry condition. The elemental and mineralogical compositions of the SRFs were determined using XRF and XRD. Effects of milling on major physicochemical properties of milled rocks were determined, including particle size (Malvern Mastersizer), surface area (BET-N2), quantities of amorphous constituents (XRD, oxalic acid-oxalate extraction, TEM), extractable cations (1M CH3COONH4 pH 7), pHH2O, and electric conductivity. Dissolution kinetics in 0.01M acetic-citric acids (for 56 days) and soil (for 10 months) were determined. Based on the results of these laboratory experiments, a glasshouse experiment was carried out for 12 months to evaluate the effects of SRF application on growth and nutrient uptake of ryegrass grown on several soils. Milling reduced particle size, enhanced amorphism, and increased the release of structural cations from the rocks, with the effects due to dry milling being greater than for wet milling. The optimum milling times which produced maximum amounts of exchangeable cations (Na, K, Ca, and Mg) were 30 - 90 min, depending on rock type. The use of NaCl and KCl as milling additives did not enhance the properties of the SRF

Thesis (M.S.)--Mississippi State University. Department of Geosciences. / Title from title screen. Includes bibliographical references.

Digitized by Kansas State University Libraries

Call number: LD2668 .T4 1956 W56 / Master of Science