As a tool in discriminating basic rocks from different tectonic settings, a type of diagram was developed that employs three ratios of trace elements. The diagram separates basic rocks formed in mid-ocean ridge, intra-plate, and volcanic arc settings. It can be used to differentiate basalts from marginal basin, forearc, and arc rift zone settings. A second application of this type of diagram, employing major elements, distinguishes tholeiitic, calcalkaline, and boninitic series volcanic rocks. The southern part of the Foothills terrane, western Sierra Nevada, California, is composed chiefly of Jurassic-Triassic(?) metavolcanic and metasedimentary rocks of lower greenschist grade. Major tectonism affecting the terrane, associated with the Late Jurassic-Early Cretaceous Nevadan orogeny, was sinistral transpression with shearing along the Bear Mountains and Melones fault zones. The line of slip in high shear strain regions is approximated by the modal stretching lineation, which is at a rake of approximately 45° SE to the general shear zone orientation, suggesting sub-equal components of strike slip and dip slip. The sense of shear from kinematic indicators is consistently east side to the northwest. The terrane hosts three types of syngenetic massive sulfide deposits: Cyprus-type Cu deposits, Kuroko-type Zn-Cu-Pb deposits, and Besshi-type Cu-Zn deposits. The Cyprus-type deposits lie at the top of a Triassic(?) tholeiitic - basalt sequence in the lower Penon Blanco Formation. The deposits are part of an ophiolitic sequence that appears to have formed in an open-ocean spreading center environment. Felsic lava facies host the Kuroko-type deposits at the top of the Middle to Late Jurassic upper Gopher Ridge Formation, a dominantly bimodal sequence of meta-rhyolitic lavas and tuffs and meta-basaltic lavas. The tectonic setting appears to have been an arc-rift zone that formed during the transition from arc volcanism forming the lower Gopher Ridge Formation to younger basinal sedimentation forming the Mariposa Formation. The Besshi-type deposits are sediment-hosted in the Late Jurassic Mariposa Formation. They appear to have formed in the median part of a long linear basin between rifted arc segments. The inferred tectonic setting of the sulfide deposits was an early back-arc or interarc basin, which may have been related to transtensional tectonics.

Pollen analysis of two surface transects of modern soil samples and four stratigraphic sections from the central Sierra Nevada of California have provided a climatic record covering the time interval since the recession of the last glaciers of the Wisconsin glaciation. Two separate warm intervals are recognized between the recession of the Wisconsin glaciers and the reappearance of glaciers in the Sierra during the Little Ice Age.

To the Southern Paiutes, the Spring Mountains are the center of Creation. They believe that they, as a people, were created in these mountains at the beginning of time. Southern Paiutes believe that the Spring Mountains constitute a living being that has a zoomorphic shape. This being has a head which is found at the northern end of the range at Mount Sterling, a tail located at Mount Potosi, and in the center at Mount Charleston, a womb which created life. Mount Charleston is the geographic and cultural center of the Spring Mountains. The Spring Mountains are located within the traditional Pahrump and Las Vegas districts of the Southern Paiute Nation. The mountains, today, serve as a boundary between the cities of Las Vegas and Pahrump, Nevada. In 2003, the United States Forest Service (USFS) funded an applied ethnographic study that focused on a cultural landscape assessment of the Spring Mountain National Recreation Area, Humboldt-Toiyabe National Forest. The project examined the traditional, religious, and cultural values of Southern Paiute people inherent in the Spring Mountains of southern Nevada. The study design required that Richard Stoffle and his research team from the Bureau of Applied Research in Anthropology work with tribal representatives to prepare a map through a rapid assessment to identify sites, areas, and landscapes that are of cultural and religious importance to the Southern Paiute people. The second task was to provide the USFS with an overview essay summarizing the ethnographic archival field notes and literature relevant to Southern Paiute cultural values of the Spring Mountains. The third task required field visits and interviews with tribal members that focused on the overall cultural importance of the Spring Mountains and individual places visited throughout the mountain range. This work served as the ethnographic core of the overall report and the basis for USFS management decisions and tribal consultation.

No description available.

No description available.

The Laurentian trilobite genus Clelandia Cossmann, 1902, is represented by 12 named species that range from the late Cambrian to Early Ordovician. Species of Clelandia have been described from many localities in the United States, Canada, Scotland, and Greenland and attempts have been made to employ them as tools in biostratigraphic correlation. Nevertheless, important questions persist regarding the taxonomy and phylogeny of the group. No species-level phylogenetic analysis has been attempted for the genus and its family affinity has been unclear. Previous work often has produced limited numbers of small photographs which tend to mask subtle, but critical, morphological details and confuse taxonomic identification. New collections from the Great Basin of the western United States have resulted in material representing five new species of Clelandia, three of which are formally named. Other species of Clelandia are illustrated and the type species is redescribed. C. aspina and C. bispina are reported from a new locality in east-central Nevada. The first articulated specimens from a species of Clelandia are illustrated and demonstrate multiple synapomorphies of the thorax and pygidium that strongly indicate a unique, low-diversity clade of trilobites which persisted from the late Cambrian into the Early Ordovician with similarities to the Kingstoniidae. Phylogenetic analysis shows Clelandia to contain two distinct components. One component is characterized by species with glabellar furrows, widely flared posterior projections, and exsagittal pits of the occipital furrow. A more derived component consists of species with long glabellar spines, relatively narrow posterior fixigenae, bacculae, and a unique glabellar-occipital spine structure.

This was a study on the history of the Colorado River, the water challenges of the Lower Basin states and the international water laws that govern the United States and Mexico concerning the Colorado river. The main purpose of this study was to determine possible long-term solutions to the growing water needs of the Lower Basin states and how Mexico could help. After discussing some concerns that the Lower Basin states had, research was done on the different types of desalination. This research included the different methods and their processes. MSF, MED, RO and MVC methods are discussed mentioning their different strengths and limitations. Next different possible solutions are discussed. These possible solutions include current practices and their successes. The solution that is discussed in length is water desalination as it offers another method of obtaining water. This part also discusses different ways to power the plant. As Mexico was already going to build nuclear power plants one idea was to build a plant in Mexico and use their power to run a desalination plant. This is one possible solution, to have a desalination plant desalinate water out of the Sea of Cortez in Mexico for the Southwest to use using the Mexico’s nuclear power plant to run the system. The economics of a desalination plant are discussed. The cost of building a plant, cost of desalinating the water, and water transportation costs are examined. After an examination on these different costs are completed it is discussed on who would pay for the desalination plant and who would receive the water. One possibility discussed is that Arizona, California and Nevada all pay an equal share in the cost of building the desalination plant in Mexico. California would then receive the water from the plant and thus would cut back on their consumption from the Colorado River allowing both Arizona and Nevada to increase theirs. A PEST analysis is done at the end of this study. It covers Political, Economical, Socio-cultural and Technological categories associated with this study. It covers different concerns and possible legislations that would need to be amended in order to continue with international desalination.

Thesis (M.S.)--University of Nevada, Reno, 2005. / "December 2005." Includes bibliographical references (leaves 80-86). Online version available on the World Wide Web.

Lower and Middle Devonian strata crop out on the former stable carbonate platform that existed in the Quinn Canyon Range, through the carbonate shelf edge in the Pancake Range, to the carbonate slope and outer-shelf basin in the Reveille Range. The strata of the Reveille Range record a transition from deposition on the carbonate platform in the Lower Devonian, to deposition at the carbonate platform margin, to deposition in the outer-shelf basin in the Middle Devonian. Conodonts collected from the base of the Sevy Dolomite yield a kindlei-Zone age, an indication that the Sevy Dolomite is younger than previously recognized. Throughout the Lower and Middle Devonian, carbonate strata of the Pancake Range and Quinn Canyon Range were deposited on the shallow carbonate platform. Conodonts collected from the base of the Lower Alternating Member of the Simonson Dolomite in the Quinn Canyon Range have a slightly older age (serotinus- to costatus Zone) than other eastern Nevada locations. The Lower Devonian Sevy Dolomite was deposited in a shallow carbonate subtidal through supratidal environment and is similar in outcrop throughout the ranges. Petrographic studies show that the samples are lithologically and diagenetically similar, indicating a similar intensity of dolomitization from the precursor calcareous mudstone. The Formation classifies as bioturbated mudstone and wackestone. The Middle Devonian Simonson Dolomite was deposited in shallow carbonate subtidal through supratidal environments. The Simonson Dolomite was affected by Milankovitch Cycles, glacioeustatic oscillations of sea level, producing a characteristic rhythmic bedding. The Middle Devonian Sadler Ranch Formation and Denay Limestone are lithologically and diagenetically different from the shallow water deposits of the Lone Mountain Dolomite, Sevy Dolomite, and Simonson Dolomite. The Sadler Ranch Formation and Denay Limestone were deposited at the carbonate platform edge and on the carbonate slope and outer-shelf basin, respectively. The Sadler Ranch Formation is dolomitized and may be classified as fossiliferous wackestone and mudstone. The Denay Limestone is not dolomitized and is classified as mudstone and fossiliferous grainstone and packstone. Dolomitization in the Paleozoic strata of Nevada is a secondary feature, an early diagenetic replacement of strata which were originally limestone. This replacement process was controlled by transgressions and regressions of the shoreline. Shallow carbonate platform deposits (shelfal and tidal-flat) are dolomitized, whereas deep water outer-shelf basin and slope deposits are not. / Graduation date: 1997

Graduation date: 1995