Physical Sciences and Mathematics Commons^™

Bulk Composition, Mineralogy, And Petrology Of Chondrules In Type H3 To H6 Chondrites, Gayle Elizabeth Lux

Earth and Planetary Sciences ETDs

Chondrules in thin' sections of 18 different H3 to H6 group chondrites were analyzed by 100 µm broad beam electron probe techniques. Chondrule textures, crystal, and chondrule sizes were determined microscopically. Results indicate a decrease in variance or standard deviation from chondrules of petrologic types 3 to 6 of FeO, MgO, TiO₂, MnO, K₂O, and P₂0₅ content. Mean TiO₂ and Cr₂O₃ content decrease from petrologic types 3 to 6 and mean FeO, Al₂O₃, CaO, and Na₂O increase slightly from lower to higher petrologic …

Geology And Mineralogy Of Cave Nitrates, Carol A. Hill

Earth and Planetary Sciences ETDs

ABSTRACT

Southeastern saltpeter caves have temperatures between 10-15° C and humidities between 90-99%. Saltpeter sediments are alkaline (pH= 6-9), dry and porous (moisture = 5-10 wt. %) and non-organic (low levels of compost, guano and animal remains); sediments have nitrate concentrations ranging between 0.01-4.0 wt. %, low total nitrogen (0.08-0.13 wt. %) and relatively low phosphorous (0.1-1.4 wt. %). Lixiviated cave sediments regenerate in nitrate in several years. Areal extent of cave nitrate is uniform; vertical concentration is in the top few meters of sediment. Nitrate is a minor constituent in sulfate speleothems (up to 1 wt. %). Surface and …

Petrology And Structure Of Precambrian Rocks In The Bosque Peak Quadrangle, North Manzano Mountains, Central New Mexico, Duncan L. Edwards

Earth and Planetary Sciences ETDs

Precambrian metamorphic rocks in a part of the North Manzano Mountains, New Mexico, underwent regional synkinematic greenschist facies metamorphism. Abundant green hornblende in greenstones and muscovite, chlorite, and biotite in metapelites tentatively suggest p4 kb and TC during metamorphism. The greenstones were probably derived from basic volcanic rocks; the metapelites were probably derived from shales, siltstones, clay-rich sandstones, cherts (7), and mature quartz sandstones.

The oldest exposed rocks are the Moyos metasediments, a sequence of phyllites and schistose grits that is lithologically transitional to a younger greenstone complex of mostly aphanitic greenstone with intercalated phyllites and metasiltstones and intrusive metadiorite. …

A Petrographic And Chemical Study Of Axinite And Scapolite Occurrences In The White Oaks Mining District, Lincoln County, New Mexico, Karen Ricciardi

Earth and Planetary Sciences ETDs

The purpose of this thesis is to report and discuss the chemistry and petrology of the axinite and scapolite occurrences in the White Oaks mining district, Lincoln County, New Mexico. Sampling, reconnaissance field geology, chemical analysis of rock samples, petrographic studies, and unit-cell d terminations for axinite and scapolite were completed for this investigation. The data was used to determine the conditions of formation for the axinite and scapolite.

The axinite is found in small pods, or nodules, of marble near the contact with the syenite-monzonite porphyry stock. The variety of axinite is ferroaxinite which occurs with calcite, actinolite, and …

Geology Of The Cerros Del Rio Volcanic Field, Santa Fe, Sandoval, And Los Alamos Counties, New Mexico, Jayne Christine Aubele

Earth and Planetary Sciences ETDs

The Cerros del Rio volcanic field is located about 10 km west of Santa Fe, New Mexico and southeast of the Jemez Mountains volcanic complex. The field lies on the Jemez- La Bajada constriction which separates the Española and the Albuquerque-Belen basins of the Rio Grande rift. At this point the rift is laterally offset 30 km. Approximately 180 sq km were mapped for this study. The northwestern map boundary parallels White Rock Canyon, a 300 m gorge which has been cut by the Rio Grande within the past 1 m. y. About 60 vents were discovered in the area, …

Precambrian Geology And Ore Deposits Of The Pecos Mining District, San Miguel And Santa Fe Counties, New Mexico, William Duncan Riesmeyer

Earth and Planetary Sciences ETDs

The Precambrian terrane north of Pecos, New Mexico, contains meta­volcanic and metasedimentary rocks. The subaqueous volcanic rocks are of bimodal composition (basalt-rhyolite). Volcanism was cyclic; three partial or complete cycles are exposed in the study area. A cycle con­sists of basal basalt, overlying rhyolite and a cap of banded iron form­ation. The chemical characteristics of the volcanic rocks are similar to those of several modern island arcs, suggesting the Pecos volcanic sequence may represent a portion of a similar Precambrian system.

Diverse structural elements in the study area. are related to four periods of deformation: 1) a Precambrian compressional event, …

Uranium And Other Trace Element Geochemistry On The Hopi Buttes Volcanic Province, Northeastern Arizona, Catherine E. Sullivan

Earth and Planetary Sciences ETDs

The Hope Buttes volcanic province lies on the southwestern flank of the Black Mesa Basin in northeastern Arizona. Over 200 diatremes occur in this region. The diatremes fill funnel-shaped vents with maar-craters at the surface. They were formed by phreatomagmatic eruptions along existing northwest-southeast fractures during mid-Pliocene time. Anomalous concentrations of uranium occur in at least 20 of the diatremes. The diatremes and dikes which feed them are composed of monchiquite, a feldspar-free lamprophyre containing analcite, and limburgite, a lamprophyre with or without feldspar in a glassy matrix. The presence of zeolites, serpentine, calcite filling fractures, and the high Fe …

Experimental Permeability Studies At Elevated Temperature And Pressure Of Granitic Rocks, Jared Michael Potter

Earth and Planetary Sciences ETDs

Permeability of quartz monzonite from the Los Alamos hot-dry-­rock geothermal well GT-2 was experimentally measured as a function of pressure and temperature. Permeability apparatus slightly modified from that developed by Brace and others (1968) was used in the experiments. Flow rate through the sample was measured using a transient pressure decay method. When combined with the physical characteristics of the sample and several system parameters, this flow rate yielded permeability (k). Permeability of the GT-2 rocks from depths of 8580 ft and 9522 ft behaves like Westerly granite for changes in effective confining pressure. However permeability of these rocks behaves …