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Typescript. / Thesis (Ph. D.)--University of Hawaii, 1967. / Bibliography: leaves [175]-181. / vii, 181 l illus., map, tables

Thesis (Ph. D.)--University of Hawaii at Manoa, 1995. / Includes bibliographical references (leaves 207-215). / Microfiche. / xiii, 215 leaves, bound maps (some col.) 29 cm

<p> Altered olivine tholeiite basalt on Mauna Ulu Volcano, Hawaii was examined petrographically and chemically to determine the mineralogy of the alteration products. Colour plays an important role in determining a general trend of alteration. </p> <p> The processes involved in the formation of Mauna Ulu have little effect on the alteration. The major influence is the type of volcanic gas and its constant interaction with the basaltic lava over an eight year period. The gas is oxidized as it cools, resulting in a zoning of different alteration products in a variety of colours and compositions. </p> <p> The major alteration phase was determined to be amorphous opaline silica. Other species present are hematite and sulphur, with minor halides, sulphates and sheet silicate (chlorite). </p> / Thesis / Bachelor of Science (BSc)

Seventeen electromagnetic transient soundings were done on the lower east flank of Kilauea volcano, Hawaii. Each sounding is based on the response or the earth as a function of time to a step function of current in a horizontal linear source. Interpretation of these response measurements is usually done by matching the data to standard model curves or asymptotic expressions; however, these methods presuppose that each datum has been measured with a relative precision (e.g. a precision of 5%) whereas, sounding, each datum is commonly measured with an absolute precision (e.g. a precision of 10µv). Therefore, a general inversion technique based on linear comparisons between the data and model values was used for the interpretations of the data in this study. The resulting geoelectric model shows that the structure is uniform vertically to a depth of 1000 m below sea level. There are broad, but distinct, lateral variations in the interpreted conductivity values ranging from 0.10 to 0.16 -mho/m in most of east Puna to anomalous values of 0.30 to 0.50 mho/m in a particular area south of the rift at Puu Honuaula (see Figure 7). Based on these conductivity estimates, groundwater temperatures in the anomalous area are not expected to exceed 1500 C to depths of 1000 m below sea level. / ill / maps

Using the controlled-source electromagnetic technique, resistivity soundings were obtained at 49 •locations around the summit caldera and upper rift zones of Kilauea volcano. Each sounding consisted of vector measurements of the magnetic field induced by a large-moment horizontal loop current source at discrete frequencies between 0.04 and 8 Hz. The source-to-sensor distances ranged from 2.5 to 13 km. The data have been computer-inverted to produce a best-fitting horizontally layered earth model. Although each sounding's interpretation is different in detail, the volcano’s structure appears simple and can be represented by four, subhorizontal layers. The surface layer is highly resistive and coincid.es with. the dry, basaltic overburden. At a depth of 500 to 1000 m, resistivities decrease abruptly to between 30 and 50 ohm-m, marking the top of the water-saturated zone. The third layer occurs between 2 and 3 km depth and has a resistivity of less than 10 ohm-m and a total conductance of about 200 mhos. This layer is underlain everywhere by highly resistive rock to a depth of at least 6 km, the estimated limit of penetration by this study. Pockets of low resistivity (less than 20 ohm--m) occur irregularly within the high-resistivity basement. Because of its widespread occurrence, 'the shallower conductive layer (layer 3) is probably water-saturated rock at high, temperature; however, the possibility of thin, intruded sills of magma contributing to the low resistivities cannot be refuted, The pockets of low resistivity within layer 4 occur at a depth of 5 km and are believed to be magma chamber 2 to 3 km deeper than models derived from earthquake hypocenter location and surface deformation studies. / ill

Graduation date: 2005