Several volcanic flows lie between Death Creek and Dairy Valley Creek, near Etna, Utah. The major, central portion of the volcanic flows is composed of dacite and dacite vitrophyre. An elongate ridge in the southeastern corner of the study area and several small outcrops in Death Creek Valley are composed of rhyolite and rhyolite vitrophyre. Additional rock types include conglomerate, volcanic ash, and tuffaceous sedimentary rock of the Tertiary Salt Lake Formation, Paleozoic limestone, and Tertiary basalt. Dacite and dacite vitrophyre samples are porphyritic, containing phenocrysts of plagioclase, quartz, biotite, amphibole, orthopyroxene, and iron-titanium oxides. Rhyolite and rhyolite vitrophyre samples are porphyritic, containing phenocrysts of plagioclase, alkali feldspar, quartz, and iron-titanium oxides, with minor amounts of biotite and amphibole. Plagioclase phenocrysts are complexly twinned, zoned, and corroded in dacitic samples; whereas, they are simply twinned, unzoned, and uncorroded in rhyolitic samples . Quartz and alkali feldspar phenocrysts contain glass-filled inclusions and are subrounded in rhyolitic samples. Average chemical analyses of five dacitic sample yield weight percent: SiO2, 69.11; TiO2, 0.31; Al2O3, 14.18; Fe2O3, 1.26; FeO, 1.23; MnO, 0.04; MgO, 0.54; CaO, 2.27; Na2O, 3.30; K2O, 4.07; P2O5, 1.23; H2O+, 1.89; H2O-, 0.46; total, 99.27. Average chemical analyses of three rhyolitic samples yield weight percent: SiO2, 76.66; TiO2, 0.12; Al2O3, 11.80; Fe2O3, 0.58; FeO, 0.43; MnO, 0.01; MgO, 0.09; CaO, 0.78; Na2O, 2.69; K2O, 5.26; P2O5, 0.02; H2O+, 1.17; H2O-, 0.22; total, 99.85. The volcanic flows of the study area are believed to be derived from fusion of sialic material within the crust which differentiated to form dacite and rhyolite. The dacite is believed to be the first magma extruded in the study area; whereas, the rhyolite represents the later extruded magma. Evidence supporting this relative emplacement is the restriction of rhyolite to the southeastern corner of the study area and the intrusion of rhyolite into dacite in the narrows of Death Creek Valley. The volcanic flows of the study area are believed to have been derived during the second stage of Basin and Range volcanism beginning approximately 14 million years ago. The study area rhyolite has chemical compositions similar to those rhyolites of bimodal basalt-rhyolite fields formed during the second stage of Basin and Range volcanism which includes high silica contents, higher alkali to calcium ratios, and greater sodium contents compared with rhyolite of calc-alkalic fields.

Basalt flows occur in the Snowville area of north-central Utah and the Table Mountain and Holbrook areas of south-central Idaho. All basalt flows are aphanitic in groundmass, and contain olivine, plagioclase, augite, and opaque oxides. They can be distinguished by texture. Snowville basalt has predominantly subophitic to intergranular textures. Table Mountain basalt is fine grained, with stumpy groundmass plagioclase and equant ilmenite crystals. Holbrook basalt has pilotaxitic to intergranular textures, with the presence of plagioclase phenocrysts and characteristic exsolution lamellae in Fe-Ti oxides. The olivine grains in Holbrook area are intensely oxidized to Fe-Ti oxides. Snowville basalt contains olivine phenocrysts (Fo88 -Fo44 ) in a groundmass of olivine (Fo63 -Fo47), augite (Wo42 -Wo36), and plagioclase (An77-An52). The lower flow unit of Table Mountain basalt contains olivine phenocrysts (Fo88-?) in a groundmass of augite (Wo44 En44 Fs17), and plagioclase (An58-An48). The upper flow unit of Table Mountain basalt has olivine phenocrysts (Fo82-Fo65), plagioclase phenocrysts (An73-An67), and plagioclase groundmass (An64-An55). The Holbrook basalt is composed of olivine phenocrysts (Fo67-Fo57)and plagioclase phenocrysts (An68-An43 ) in a groundmass of olivine (Fo59Fos53) augite (Wo39 En44 Fs17), and plagioclase (An67-An35). The basalts of the Snowville and Holbrook areas, represent petrographic, mineralogical, and chemical characteristics of both olivine-tholeiitic basalt and alkali-olivine basalt, whereas Table Mountain upper and lower flow units show their affinity with alkali-olivine basalt. Chemically, basalts from these three areas are consistently high in silica, magnesium, and alkali content. The Snowville basalt has a high Ba content and high strontium isotope ratio. Fractional crystallization models indicate that the basalt flows from the three different areas are genetically unrelated. The testing also suggests that the upper and lower flow units of the Table Mountain area are not genetically related. The basalts of the three areas also can not be evolved from the basalts found at Kelton, the Rozel Hills or Black Mountain. Basalts of the Snowville area have consistently higher magnesium and silica contents than Snake River basalt, Kelton area basalt, and Rozel Hills and Black Mountain basalt, indicating that they may represent what was initially a very primitive basaltic lava. High Ba content and strontium isotope ratio indicate that the Snowville basalt was contaminated by crustal material. Table Mountain and Holbrook basalt may have formed as a result of partial melting from a pyrolite or garnet peridotite mantle.

Two basalt flows and an andesite fissure eruption occur in the Rozel Hills - Black Mountain area in Box Elder County, Utah. Both basalt flows are aphanitic, and contain olivine, plagioclase, augite, and opaque oxides. They may be distinguished both chemically and on the basis of their textures. Unit 2 basalt is finer grained, and appears to be associated with a fault in the Black Mountain area. Chemically, it is similar to high-iron lavas in the Craters of the Moon, Idaho area. It has higher alkali, total iron, and titanium contents that Unit 1 basalt. Unit 1 basalt is similar to other tholeiitic basalts in the Basin and Range province. It is coarser-grained and has higher silicon, magnesium, aluminum, and calcium contents than Unit 2 basalt. While the basalts have characteristics of alkali-olivine basalts, such as absence of calcium-poor pyroxene, and a high alkali to silica ratio, both units are hypersthene- and olivine-nonnative and classified as olivine tholeiites. Subsurface basalt in the area appears to represent both lava types, but extensive alteration makes comparison difficult. Andesite from the area is aphanitic, and contains plagioclase, orthopyroxene, and opaque oxides. Temperatures of equilibration calculated from co-existing magnetite and ilmenite range f rom 1148°C to 745°C for basalt. Temperatures calculated from co-existing olivine and clinopyroxene range from 1009°C to 994°C. While the two basalt units cannot be related by fractional crystallization at surface conditions, some parent - daughter relations are likely within each unit, and the andesite is most likely a differentiation product of Unit 1 basalt. Partial melting of pyrolite and spinel lherzolite mantle compositions to produce Unit 1 and Unit 2 basalts was investigated. Since no unique temperature and pressure of equilbration for these melts and residu~l material from each mantle type was found, it is concluded that partial melting of a mantle of pyrolite or spinel lherzolite composition did not produce these lavas. Unit 2 basalt may be derived from Unit 1 basalt by fractionation of high pressure (8 kb) phases. This mechanism, similar to that proposed for the Craters of the Moon - Snake River Plain system, may account for an evolved basalt (Unit 2) with a lower silica content than a less differentiated basalt (Unit 1).

Mount St. Helens returned to an active eruptive state March 20, 1980. Since then explosive and dome building eruptions have caused major topographic changes to the mountain and surrounding drainages. Monitoring of the southern side of the mountain by six tiltmeters at distances between 6 km and 12 km was conducted during the period of July 1, 1980 to December 31, 1980. Records obtained from the tiltmeters were analyzed and compared to data from precision geodetic surveys.

Dam removal is increasing as dams age, yet little is understood about the pedogenic response to dam removal. This study reports on the edaphic changes of reservoir sediments and vegetation cover one year following removal of a small earthen dam in Northern California. In August 2012, I sampled surface sediments from the former Dream Lake reservoir in Lassen Volcanic National Park, and compared their physical and chemical properties with soil samples from two reference sites. I also estimated percent cover of vegetation in the former reservoir and reference sites. My results show that the reservoir was under reduced conditions, as determined by gleyed soil color and a higher pH when compared to reference samples. In contrast to reservoirs on larger river systems which tend to be sinks for organic matter, Dream Lake showed a reduction in organic matter when compared to reference locations. My results suggest reservoirs created by dams cannot be considered to have similar sediment properties, namely increases in organic material. Unlike other studies that found former impoundments invaded by non-native species, the former Dream Lake site has been colonized by native grasses, sedges, and rushes. This study documents the edaphic properties and vegetation response of a small reservoir one year after dam removal, and suggests a more thorough investigation of those properties prior to undertaking costly restoration of these highly dynamic systems.

The purpose of the investigation was to map the geology of the north end of Craters of the Moon National Monument and surrounding area. A stratigraphic sequence of Late Paleozoic sedimentary and Tertiary volcanic rocks was compiles and the structures of these rocks and contact relationships with intrusions were delineated. Grade and facies of contact metamorphism were defined. The Snake River Plain basalts were also mapped. The sources of these flows were determined where possible. Preexisting structures and relationships of vents to earlier faulting were explored in ascertaining extensions of the Great Rift Zone into the Pioneer Mountains. Petrographic descriptions of the rock units were completed. Study of the economic geology was not undertaken. The interested reader is referred to Nelson (1969) for descriptions of the mineral deposits in the Lava Creek Mining District.

This study outlines the ash (tuff) bed stratigraphy (tephrostratigraphy) in the middle Eocene Chumstick Formation of central Washington. The tuff beds provide local marker beds enabling interpretation of the stratigraphy and structure of the formation. The chemical signature of these units provides the basis on which the units can be traced over broad areas in the basin of deposition. Correlations of tuff beds were obtained over distances of 41 km.

El objetivo principal de este trabajo consiste en una propuesta de negocio a través de la cual se comercializa la bentonita con el fin de que las personas que la utilicen como una mascarilla, que puedan cuidar su piel y disfruten de los beneficios que esta les brinda. Algunos de estos son la eliminación de impurezas y residuos, reducción del acné. Asimismo, este tipo de ceniza volcánica suaviza la piel, puede ser utilizada por personas que cuentan con piel sensible y rosácea. Las campañas publicitarias y las nuevas exigencias sociales han determinado ciertos estereotipos y características que se deben cumplir para que una persona se considere estéticamente atractiva. Afectando de manera directa el autoestima y estado de ánimo de los individuos que no cumplen con ellas. A partir de esta situación, Bitamask brinda a las personas la oportunidad de cuidar y mejorar la apariencia de su piel, con el objetivo de solucionar o reducir imperfecciones que puedan tener con el fin de incrementar su autoestima y mejorar su estado de ánimo. Por otro lado, este trabajo fue elaborado de acuerdo a las normas vigentes dictadas por la Universidad Peruana de Ciencias Aplicadas y ha sido realizado por alumnos de la Facultad de Negocios. A continuación, se presentará la investigación y propuesta realizada. / The main objective of this paperwork is a business proposal through which bentonite is marketed so that people who use it as a mask, can take care of their skin and enjoy the benefits it offers. Some of these are the elimination of impurities and dirt, and reduction of acne. Also this type of volcanic ash softens the skin and can be used by people who have sensitive skin and rosacea. Advertising campaigns and new social demands have determined certain stereotypes and characteristics that a person must have in order to be considered aesthetically attractive. Directly affecting the self-esteem and state of mind of people who do not comply with them. From this situation, Bitamask offers people the opportunity to care for and improve the appearance of their skin, with the aim of solving or reducing imperfections that may have in order to increase their self-esteem and improve their mood. On the other hand, this paperwork was prepared in accordance with the regulations dictated by the Peruvian University of Applied Sciences and has been carried out by students of the Faculty of Business. Now, the research and proposal made will be presented. / Trabajo de investigación

<p>Chemical weathering of highly reactive mafic and ultramafic igneous rocks may be a key sink in the global carbon cycle. Understanding how uplift of these rocks during arc-arc and arc-continent collisions through earth history has affected the evolution of global climate, including the onset of icehouse periods, requires improved constraints on the relative sensitivity of their weathering rates to physical erosion vs. climate. If weathering rates depend chiefly on erosion, then tectonic uplift of mafic and ultramafic rocks may have a strongly destabilizing effect on global climate. Conversely, if weathering rates are limited primarily by temperature or runoff, then a negative feedback mechanism between weathering and climate may attenuate the effects of rock uplift. This work characterizes the relationship between chemical weathering rates, physical erosion rates, and climate in tropical, montane watersheds in Puerto Rico that are underlain by volcanic arc rocks and associated ophiolitic serpentinite. Key to this analysis are new constraints on long-term erosion rates on these rocks from cosmogenic Cl-36 produced <em>in situ</em> in magnetite. These cosmogenic erosion rates are paired with classical measurements of stream solute fluxes and sediment geochemistry across runoff gradients to quantify the limits to volcanic arc rock and serpentinite weathering rates. </p> <p><br></p> <p>This work is divided into three chapters. Chapter 2 constrains the altitude scaling behavior of Cl-36 production in magnetite. This allows erosion rates to be determined more accurately in watersheds near sea level in Puerto Rico. Chapter 3 demonstrates that volcanic arc rock weathering rates in the humid tropics are more strongly limited by physical erosion than by climatic factors. However, a positive correlation between erosion and runoff observed in this landscape may enhance the coupling between climate and weathering rates. Chapter 4 finds that, in contrast to volcanic arc rocks, serpentinite weathering is strongly limited by runoff and weakly limited by erosion. These results are presented as empirical power-law relationships that can be readily applied in global carbon cycle modeling.  </p>

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