Earth Sciences Commons^™

Refining Models Of Crustal Growth And Evolution In Southwestern Laurentia With Paired U-Pb And Lu-Hf Analyses Of Igneous And Detrital Zircon, Mark E. Holland

Earth and Planetary Sciences ETDs

The origin and evolution of continental crust is a fundamental and debated topic in geoscience. For over thirty years, Proterozoic crust of the southwestern United States has been a field laboratory for studying orogenic processes in the middle crust, and the growth of continental lithosphere via accretionary orogenesis. Three distinct crustal provinces are delineated based on differences in isotopic, structural, and geochronologic characteristics. To address questions about the origin of each province, this dissertation is composed of three chapters that present new U-Pb and Lu-Hf isotope analysis of plutonic, volcanic, and detrital zircon from the oldest known rocks in each …

Volatile Light Hydrocarbons In Geothermal Gas Emissions From Yellowstone National Park, Usa, And Comparisons To El Salvador And Honduras, Bethany Burnett

Earth and Planetary Sciences ETDs

Twenty-six samples from hot springs and fumaroles in Yellowstone National Park (YNP) and 11 in Central America were analyzed for inorganic gases (CO₂, SO₂, H₂S, HCl, Ar, N₂, CO, H₂, He, 0₂), methane, and trace volatile light hydrocarbons. Stable isotope analyses of carbon and nitrogen were used in conjunction with the gas geochemistry to determine potential sources of hydrocarbons.

δ¹³C-CH₄ values ranged between -37.6 and-18.2‰ for YNP, from -31.9 to -30.2‰ for El Salvador, and from -38.8 to -23.9‰ for Honduras. δ¹³C-CO_{2 …}

Seasonal Biogeochemistry And Mineral Cycling Of The Middle Rio Grande Alluvial Aquifer, New Mexico, David Stewart Vinson

Earth and Planetary Sciences ETDs

The Rio Grande in central New Mexico flows through a semi-arid, historically aggrading Quaternary rift basin. Flow regulation measures include dams, irrigation diversions, levees, and bank stabilization. These have caused severe impairment including incision, lowered water tables, and less overbank flooding; disrupted groundwater - surface water interactions; altered seasonal organic carbon dynamics; and declining native biota. Previously dynamic flowpaths in the shallow alluvial aquifer (hyporheic corridor) have become are less reversible due to parallel drain ditches with lower beds than the river. These ditches impose relatively static hydraulic gradients on the alluvial aquifer that force water to flow from the …

Biogeochemistry Of The Middle Rio Grande Bosque: Links Among Surface Water, Groundwater, And Sediments, Susan E. Block

Earth and Planetary Sciences ETDs

The potential for water contamination is great in areas where land use is both urban and agricultural. Such land uses can load the surface water and groundwater with nutrients and toxic trace metals. Water pollution can be further increased when natural watersheds have been altered by human activities. The surface and groundwaters of the Middle Rio Grande, NM, USA are part of one such ecosystem.

Because redox processes are important controls on nutrient cycling and contaminant transport, it is vital to understand the redox zonation of an aquifer. This research has been conducted to address such biogeochemical zonation in the …

A Late Pleistocene And Holocene High-Resolution Glacial And Paleoclimate Record From The Southern Sangre De Cristo Mountains, Northern New Mexico, Jake Armour

Earth and Planetary Sciences ETDs

Bog deposits in the Winsor Creek drainage basin, southern Sangre de Cristo Mountains, New Mexico contain a high-resolution record of Pleistocene to Holocene glacial activity. Sediment cores were recovered from an alpine bog (elevation 3,100 m) behind a Pinedale age moraine, 2 km from a high-elevation (-3600 m) cirque. Three cores reached glacial talus and consist of -6 meters of finely laminated to coarsely laminated lake clays, grading into gyttja. Superimposed on this long-term, lake-bog transition record are many distinct coarse-grained detrital packages punctuating times of rapid environmental change.

Accelerator mass spectrometry (AMS) carbon dating, sedimentology, variations in rock magnetic …

Genesis And Evolution Of Proterozoic Crustal Boundaries In The Southern Rocky Mountains., Colin Arthur Shaw

Earth and Planetary Sciences ETDs

The lithosphere of the southwestern United States is a mosaic of Proterozoic arc terranes assembled to the southern margin of the Archean Wyoming craton between 1.8 and 1.6 Ga. This mosaic was profoundly transformed by ca. 1.4 Ga intracontinental plutonism, metamorphism, and tectonism. These processes of assembly and tectonic reactivation during the early stages of continental evolution laid the foundation for the development of the continental architecture of the southwestern United States.

This dissertation comprises three independent studies focused on different aspects of the Proterozoic evolution of tectonic boundaries exposed in the Southern Rocky Mountains. The first study is a …

Hydrologic Budget Analysis And Numerical Simulations Of Groundwater Flow In Los Alamos Canyon Near Los Alamos, New Mexico, Robert Norman Gray

Earth and Planetary Sciences ETDs

A hydrologic budget analysis for the Los Alamos Canyon watershed was prepared including annual budgets for the 1993, 1994, and 1995 water years and detailed budget calculations for the upper basin and middle/upper canyon areas covering nine separate stress periods from 7/10/94 to 11/2/95 corresponding to varying alluvial aquifer behaviors. Data sources included daily measurements of precipitation and snowpack depths, streamflow discharge, and latent heat energy flux from which evapotranspiration rates were determined. Average annual precipitation rates over the watershed varied from ~23 to ~31 inches during the analyzed periods. The annual evapotranspiration component was determined to represent between ~ …

The Terraces Of Cochiti Canyon: Soil Development And Relation To Tectonism In The Pajarito Fault Zone, Scott Benjamin Aby

Earth and Planetary Sciences ETDs

The history of motion on splays of the Pajarito Fault Zone in the area of Cochiti Canyon in the Jemez Mountains is examined using morphometric techniques and investigations of river terrace soils and deformation. Hypsometry, sinuosity and long-profile analysis all suggest that the main splay of the Pajarito Fault has been active in the late Pleistocene and possibly Holocene, but no calibration is available that numerically constrains this activity. Terraces were mapped and correlated based on soil development and landscape position, Correlation revealed the presence of three strath terraces between 87 and 18 .5 meters above present grade and one …

Stratigraphy, Chemistry And Petrogenesis Of Volcanic Rocks Of The Mid-Tertiary Boot Heel Volcanic Field, Southwestern New Mexico And Southeastern Arizona, Charles R. Bryan

Earth and Planetary Sciences ETDs

The mid-Tertiary Boot Heel volcanic field is located in the Basin and Range Province of southwestern New Mexico and southeastern Arizona. The field is defined on the basis of nine regional ash-flow tuffs, which have been correlated throughout the area, and for which probable source cauldrons have been identified. These tuffs are: tuff of Woodhaul Canyon (35.3 Ma); Bluff Creek Tuff (35.1 Ma); tuff of Steins (34.4 Ma); Oak Creek Tuff (33.5 Ma), tuff of Black Bill Canyon (stratigraphically constrained to 32.7-33.5 Ma); Gillespie Tuff (32.7 Ma); tuff of Horseshoe Canyon (27.6 Ma); Park Tuff (27.4 Ma); and Rhyolite Canyon …

Freshwater Imperative - Executive Summary, Long Term Ecological Research Network

Long Term Ecological Research Network

Fresh water is a strategic resource in a rapidly changing world. It is a source of energy, an avenue of transportation, habitat for a myriad of organisms, and essential for life. Fresh water structures the physical landscape, is a central feature of climate, and exerts major influences on economic growth and demographic patterns. Yet, as the human population increases, more and more demands are placed on freshwater ecosystems. Already, sufficient clean water and healthy aquatic habitats have become a rare natural resource.

Understanding the abilities and limits of freshwater ecosystems to respond to human-generated pressures has become vital to long-term …

Soil Biodiversity: Its Importance To Ecosystem Processes, Long Term Ecological Research Network

Long Term Ecological Research Network

Report of a Workshop Held at The Natural History Museum, London, England

Holocene And Modern Geomorphic Response To Forest Fires And Climate Change In Yellowstone National Park, Grant A. Meyer

Earth and Planetary Sciences ETDs

The Yellowstone fires of 1988 provided an opportunity to observe the geomorphic impact of widespread, intense forest fires on a mountain environment. Post-1988 fire-related sedimentation events also served as geomorphological and sedimentological analogs which were used to interpret a Holocene stratigraphic record of fire-related alluvial activity. Research focussed primarily on the steep-walled glacial trough valley of Soda Butte Creek, and parts of the Slough Creek and Lamar River drainages in northeastern Yellowstone.

All of the examined major post-1988 fire-related sedimentation events involved the generation of widespread surface runoff from brief, intense summer convective-storm precipitation on steep slopes in intensely burned …

Soil Warming Experiments In Global Change Research, Long-Term Ecological Research Network

Long Term Ecological Research Network

The report of a workshop held in Woods Hole, Massachusetts.

There is widespread consensus that the global temperature is likely to increase by about 1° C during the next 35 years as a result of enhanced retention of the Earth's reradiation by "greenhouse" gases (IPCC 1990). The anticipated rate of global warming will exceed all known climate changes during human history and during the development of all human socio-economic systems, including agriculture. These changes in climate will have unprecedented impact on natural and managed ecosystems.

As a result of concern about soil warming caused by anticipated global climate change, the …

The Magmatic History Of An Aubrite Parent Asteroid: Evidence From Igneous Clasts And Trace Elements, Maya Monica Wheelock

Earth and Planetary Sciences ETDs

Norton County aubrite contains numerous igneous-textured clasts that survived severe brecciation. These clasts were studied in order to obtain information about the suite of original igneous lithologies that crystallized on an aubrite parent body. The majority of igneous clasts are pyroxenites (enstatite, with minor diopside, +/- forsterite) and orthopyroxenites (enstatite, +/- forsterite). Phase relations and textural evidence are consistent with formation from a nearly pure enstatite magma body or magma ocean, at (or near) the surface of the parent body.

A new sulfide-dominated lithology was identified in Norton County. The sulfide portion is dominated by coarse-grained oldhamite (CaS) containing rounded …

Geochemistry Of Metal Segregation In Aubrites, And The Origin Of Their Metallic Phases, Ignacio Casanova

Earth and Planetary Sciences ETDs

In this work, I have carried out a petrographic and geochemical study of the metallic particles present in aubrites with the aim of constraining ideas about their origin and evolution. The extremely low oxygen fugacities under which enstatite meteorites formed (e.g. Larimer and Buseck, 1974; Fogel et al., 1989) and their consequent unique composition make interpretations difficult due to the lack of experimental data on highly reducing systems. I have tried to overcome the paucity of experimental data by using a theoretical thermodynamic approach to study the significance of such unique compositions based on three main themes: (1) the …

Hydrology Of A Large, Closed Arid Watershed As A Basis For Paleohydrological And Paleoclimatological Studies In The Mojave River Drainage System, Southern California, Yehouda Enzel

Earth and Planetary Sciences ETDs

A physical link between anomalous, present-day atmospheric circulation patterns over the North Pa1cific Ocean, extreme storms in southern California, the largest floods of record and lake stands in the Mojave River watershed in the Mojave Desert is demonstrated by analyzing hydrologic and climatic data. This link is then used as a modem analog to interpret hydroclimatic conditions during the latest Quaternary recorded in lake deposits in the Silver Lake playa, the terminal basin of the of the Mojave River.

The Mojave River filters out small to medium floods by discharge loss through infiltration into the alluvial aquifer and allows only …

Hillslope Processes On Late Quaternary Cinder Cones Of The Cima Volcanic Field, Eastern Mojave Desert, California, Claire Estelle Renault

Earth and Planetary Sciences ETDs

Four basaltic cinder cones of the cima volcanic field were studied in an attempt to understand the geomorphic and volcanic processes involved in the constructional and degradational evolution of late Quaternary cinder cones in an arid climate. Modern hillslope processes were mapped on cone slope and soil and subsurface stratigraphy were documented in the surrounding debris-apron deposits. In addition, morphometric parameters shown to be sensitive to cinder cone age (Dohrenwend et al., 1986) were measured on the four cinder cones to evaluate previous studies which estimated the relative or absolute age of cinder cones based only on morphologic changes in …

Quaternary Alluvial Sequence Of The Upper Pecos River And A Tributary, Glorieta Creek, North-Central New Mexico, Paul Arthur Karas

Earth and Planetary Sciences ETDs

Quaternary alluvial deposits preserved on terraces along the Pecos River and a tributary, Glorieta Creek, provide a record of the evolution of these two drainages. Alluvium deposited by the Pecos River can be subdivided into six units on the basis of relative topographic position and degree of soil development on original surfaces. Deposits consist of thin (1 to 10m) veneers on scattered strath terrace remnants. Only four Quaternary alluvial units have been identified along Glorieta Creek. Alluvium deposited by this stream forms nearly continuous fill terraces of thickness equal to or greater than the Pecos River alluvium. Alluvial deposits of …

Geology And Petrogenesis Of Ash-Flow Tuffs And Rhyolitic Lavas Associated With The Gila Cliff Dwellings Basin-Bursum Calder Complex, Southwestern New Mexico, Sheila June Seaman

Earth and Planetary Sciences ETDs

The Mogollon-Datil volcanic field of southwestern New Mexico was the site of extensive mid-Tertiary felsic volcanism. The Bursum caldera-Gila Cliff Dwellings basin is a volcanic complex in which stratigraphic and compositional relationships between eruptive units are controversial. Uncertainties associated with the complex include the relative ages of the two overlapping structures, the caldera of origin of ash-flow tuff which fills the Gila Cliff Dwellings basin, and the reconciliation of stratigraphic and chemical relations between volcanic units. A stratigraphic, structural, paleomagnetic, and petrologic study of six ash-flow tuff and lava units has contributed data to several problems concerning the geologic history …

Long-Term Tributary Adjustments To Base-Level Lowering, Northern Rio Grande Rift, New Mexico, Keith Irvin Kelson

Earth and Planetary Sciences ETDs

ABSTRACT

Late Cenozoic (post-3.6 Ma) entrenchment of the Rio Grande in northern New Mexico formed a gorge over 200 m deep and induced different types of fluvial adjustments on two adjacent tributaries. Rio Hondo (drainage area 181 km2 ) has a concave-up long-profile and flows in a narrow valley containing six Quaternary strath terraces with parallel long-profiles grading to the Rio Grande. In contrast, Rio Pueblo de Taos (drainage area 1080 km2 ) has a convex-up long-profile and flows in a wide valley containing four strath terraces which do not grade to the Rio Grande. Although smaller in drainage area, …

The Virginius Vein Ore Deposit, Northwestern San Juan Mountains, Colorado: A Study Of The Mineralogy, Structure, And Fluid Inclusions Of An Epithermal Base-Metal And Silver Vein In A Volcanic Environment, Berton Woodward Coxe

Earth and Planetary Sciences ETDs

The Virginius ore deposit, Ouray and San Miguel Counties, Colorado, yielded 14.5 million oz of silver between 1880 and 1912. The deposit consists of several quartz, base-metal, and silver mineralized fissures which is hosted by Tertiary volcanic rocks of the San Juan volcanic field and was deposited in fractures radial to the northwest margin of the Silverton caldera.

Four stages of mineralization have been recognized: (I) quartz, galena, sphalerite, chalcopyrite, and argentiferous tetrahedrite; this stage comprises a bulk of the total vein material and all of the silver; (II) rhodonite, rhodochrosite, quartz, magnetit, galena, chalcopyrite, and pyrite; this stage is …

Dynamics Of Clastic Sedimentation And Watershed Evolution Within A Low-Relief Karst Drainage Basin, Mammoth Cave Region, Kentucky, John D. Pickle

Earth and Planetary Sciences ETDs

The hydrology and sedimentology of the Mill Hole drainage basin, a low-relief karst system in the Mammoth Cave Region, Kentucky, depend upon the interactions of surface and groundwater drainages and the distribution of lithologies within the basin. This basin is characterized by sinking streams in the headwaters (Glasgow Uplands) draining into cave rivers beneath the sinkhole-pocked plain (sinkhole plain), which, in turn, flow beneath a sandstone-capped upland (Chester Cuesta) and emerge at base-level springs. Karst windows expose the subterranean drainage within the Chester Cuesta.

Geology And Petrochemistry Of Ultramafic And Orbicular Rocks, Zuni Mountains, Cibola County, New Mexico, Ellen E. Lambert

Earth and Planetary Sciences ETDs

Field mapping, petrography, mineral and whole-rock chemistries have been completed on Precambrian ultramafic and orbicular rocks occurring in the Zuni Mountains, New Mexico. These rock types are surrounded by felsic igneous and metasedimentary rocks, including quartz-feldspar gneiss, quartz monzonite aplite, gneissic quartz monzonite and metarhyolite.

Two small orbicular rock outcrops occur along the contact between quartz-feldspar gneiss and gneissic quartz monzonite. Dark-green, hornblende-actinolite orbicules, having curving crystals of amphibole concentrically arranged about a central point, are set in a pink, quartz monzonite matrix. Many orbicules have been broken or deformed into irregular ellipsoids.

Metamorphosed ultramafic rocks, exhibiting original igneous textures, …

Selected Shallow Electrical Resistivity Surveys At Volcano Cliffs, Bernalillo County, And Warm Springs, Sandoval County, New Mexico, Sidney S. Brandwein

Earth and Planetary Sciences ETDs

To help assess the applicability of shallow electrical resistivity measurements in New Mexico, two diverse areas in northwestern New Mexico were chosen as electrical resistivity survey sites: Volcano Cliffs and Warm Springs.

Volcano Cliffs, 15 km northwest of Albuquerque, is an area of Pleistocene volcanic activity which manifested itself in cinder cones and basalt flows. At Volcano Cliffs five different electrode configurations were employed to test the horizontality and derive the thicknesses and resistivities of the three geoelectric units present. All electrode configurations yielded reliable results. The ambiguities presented by the principle of equivalence were successfully treated. The first geoelectric …

Quaternary Geology Of Chaco Canyon, Northwestern New Mexico, David Waxham Love

Earth and Planetary Sciences ETDs

The overall purpose of studying the Quaternary geology of Chaco Canyon is to develop an understanding of how the geomorphic system in the Chaco drainage evolved and how it presently operates. This dissertation has several subsidiary purposes; (1) to describe and relate modern sedimentary features and facies (which are likely to be preserved in the alluvial fill of the canyon) to modern geomorphic processes, (2) to use the results from the study of modern sediments to interpret exposures of alluvium in Chaco Canyon in order to reconstruct past environments, (3) to develop conceptual models of the geologic subsystems of the …

Geology Of The Eastern Part Of The Regina Quadrangle, Sandoval And Rio Arriba Counties, New Mexico, Margaret Anne Merrick

Earth and Planetary Sciences ETDs

The Regina quadrangle is located in Sandoval and Rio Arriba Counties, New Mexico, along the boundary between the northwestern margin of the Nacimiento uplift and the east-central San Juan Basin. The uplift is composed of a core of Precambrian rocks overlain by a veneer of Mississippian through Triassic sedimentary rocks. Sedimentary rocks ranging in age from Jurassic to Tertiary are upturned along the margin of the San Juan Basin.

The Precambrian rocks in the area are primarily granite to granodiorite gneiss with xenoliths of mafic and felsic metavolcanic rocks and metasedimentary rocks. These rocks have undergone greenschist facies metamorphism. Late …

Provenance Study Of The Westwater Canyon And Brushy Basin Members Of The Morrison Formation Between Gallup And Laguna, New Mexico, Ruben Martinez

Earth and Planetary Sciences ETDs

The objective of this investigation is to study the provenance of the Westwater Canyon and Brushy Basin Members of the Morrison Formation between Gallup and Laguna, New Mexico. The coarse, subarkosic Westwater Canyon Member is separated from the quartzitic sandstones of the underlying Recapture Member by an unconformity that provides a recognizable datum for correlation and a definite base for the Westwater Canyon Member.

The very pale orange, cliff-forming Westwater Canyon Member consists of Oto 137 m of very coarse- to very fine-grained, poorly sorted, subrounded to angular, arkosic to quartzitic sandstone with numerous lenses of arkosic granules and pebbles …

Petrogenesis Of Orbicular Rock, Tijeras Canyon, Sandia Mountains, New Mexico, Kathleen Affholter

Earth and Planetary Sciences ETDs

A new occurrence of orbicular rock is located in the Sandia Granite at W. long. 106° 25' 30", N. lat. 35° 04' 55" close to the granite-gneiss contact near Tijeras Canyon, Sandia Mountains, New Mexico. The orbicules, set in an aplite-pegmatite granitic matrix, have magmatic and metamorphic cores surrounded by a white plagioclase shell and one or two salmon-colored potassium feldspar shells. The outcrop occurs in two dike-like masses with thicknesses of 1 to 4 m trending N. 5° W. and N. 35° E. for exposed lengths of 16m and 46 m, and is surrounded by biotite syenodiorite and biotite …

Geology Of The Cerro Del Grant Area, Rio Arriba County, North-Central New Mexico, John Richmond Lawrence

Earth and Planetary Sciences ETDs

The present study undertook the geologic mapping and investigation of the stratigraphy, structural geology, igneous petrology and mineral resources of the Cerro del Grant area, a 75- (190 ) region near Coyote, Rio Arriba County, north-central New Mexico. The area is situated at the junction of three geologic provinces: the Chama platform, the Española Basin of the Rio Grande rift, and Jemez volcanic field.

Sedimentary rocks include 2,500 ft (830 m) of sandstone, shale, conglomerate and limestone of Late Triassic to Quaternary age. These strata are unconformably overlain by several hundred feet of mafic, intermediate and rhyolitic lavas which make …

Petrogenetic Properties Of Chondrules In Unequilibrated H-, L-, And Ll-Group Chondritic Meteorites, James Leslie Gooding

Earth and Planetary Sciences ETDs

The physical properties (size, shape, mass, density, surface morphology), bulk chemical composition (by nondestructive instrumental neutron activation analysis), texture, and phase compositions (by electron microprobe analysis) have been determined for each of 141 individual chondrules separated from a total of 11 different H-, L-, and LL-group chondritic meteorites of Van Schmus-Wood petrologic types 3 and 4. In addition, physical properties have been determined for 75 other chondrules from the same chondrites. The chondrites studied are comparatively unaltered and unequilibrated and include Tieschitz (H3), Dhajala (H3, 4), Ochansk (H4), Weston (H4), Hallingeberg (L3), Saratov (L4), Tennasilm (L4), Chainpur (LL3), Semarkona (LL3), …