Virginia Range Research Articles

Immunocontraceptive Efficacy of Native Porcine Zona Pellucida (pZP) Treatment of Nevada's Virginia Range Free-Roaming Horse Population.

In North America, range constraints due to burgeoning development increasingly encroach on wild horse habitat and necessitate effective but humane reproductive management. The largest free-roaming wild horse fertility control program by population (>3500) and territory size (≈300,000 acres) is located within Nevada's Virginia Range. Data from a field study investigated porcine zona pellucida (pZP) immunocontraception via remote dart delivery to mares in this population. Analyses aimed to measure efficacy by treatment effects on annual birth rates and population demographics and to evaluate treatment frequency and season against these variables. Analyses included mares' monthly data (January 2019-December 2022; 48 months), characterized by cumulative vaccination numbers subset into four classifications considering the vaccine as having no loss of efficacy or a loss within a 6-, 12-, and 18-month period post vaccination; from foaling data, the likelihood of being in foal and of conceiving in that month; and from age, as mature or immature (<1 years-old). A downward foaling rate and trend in the numbers of mature mares, descriptively presented at monthly intervals, showed markedly declining annual seasonal breeding peaks, with no observed change in foaling season or duration. Within four years, population coverage surpassed 70% and was associated with a 58% reduction in foaling, with only a 10% conception rate. Vaccinated mares increased proportionally: assuming a 12-month decay rate, the system reached stability at an average ≈1.0 vaccination/mare/year, providing a robust recommendation for treatment frequency contributing to best management practices.

Establishing feasibility for porcine zona pellucida immunocontraception in a large population of free-roaming horses inhabiting the Virginia Range of Nevada, USA

In North America, range constraints are increasingly encroaching on wild horse habitat, necessitating effective but humane reproductive management (Kirkpatrick and Turner. J. Zoo Wildl. Med. 1991; 23:445-452). The largest free-roaming wild horse fertility control program, both in terms of population (>4,000) and territory size (≈300 000-acres), inhabits Nevada's Virginia Range. This program, commenced in 2019, provided a unique opportunity for an extended temporal field study investigating feasibility of porcine zona pellucida (pZP) immunocontraception. Vaccine is administered via remote intra-muscular dart-delivery with an initial treatment of 0.5mL native pZP formulated with 0.5mL Freund's complete (primer) and incomplete (booster) adjuvant, respectively and thereafter at intervals ≈8-12 months. A database, continuously updated from field observations, provides individual animal records including date and type of intervention and of births, deaths and movements. This ongoing study aims to establish feasibility by evaluating vaccine efficacy measurable via annual birth rates and population demographics and concurrently analyze the effects of treatment frequency and season. For this reported initial phase, analyses included monthly data (January 2019 - December 2021; 36 months) for all females. This was characterized by:number of cumulative vaccinations subset into four further classifications considering vaccine having no efficacy loss or loss within a 6-, 12-, and 18- month period post vaccination; based on foaling data, likelihood of being in-foal; based on foaling data, likelihood of conceiving in that month; and based on age, considered as mature or immature (<1-year-old). Foaling rate and population size were descriptively presented over time at monthly intervals. Results described mean numbers of vaccinations per mature mare for any month, vaccination count in relation to conception rate (within mare) and population conception rates. A total of 1,501 individual mares were treated with administration of 4,795 vaccinations. Population data showed a decreased number of immature mares, declining pregnancy rate and a seasonal breeding peak that declined dramatically from 2020. The proportion of vaccinated mares increased steadily and by 2021 showed population coverage ≈40-80%. The most salient findings showed that the system reached stability, assuming a 12-month decay rate, at an average ≈1.0 vaccination/mare/year and can be recommended as a treatment frequency. As data collection and treatment is ongoing, future analyses will provide evidence-based and robust recommendations for best management practices.

HF01-04 THE VIRGINIA STERILIZATION ACT: A CATALYST FOR AMERICAN EUGENICS

You have accessJournal of UrologyCME1 Apr 2023HF01-04 THE VIRGINIA STERILIZATION ACT: A CATALYST FOR AMERICAN EUGENICS Davis Moore, Theodore Cisu, and Adam Klausner Davis MooreDavis Moore More articles by this author , Theodore CisuTheodore Cisu More articles by this author , and Adam KlausnerAdam Klausner More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003243.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The origins of the American eugenics movement are rooted in the Virginia Eugenical Sterilization Act of 1924. This set a historic precedent that led to the Supreme Court ruling in Buck v. Bell (1927), which legitimized sterilization to prevent the birth of more “defective” individuals. More than 3,000 men underwent forced sterilization via vasectomy in Virginia alone. METHODS: A review of historical and medical literature was undertaken, as well as analysis of academic texts on American sterilization and eugenics. RESULTS: In the early 20th century, an increasing number of physicians promoted forced sterilization of “feebleminded” men and women to prevent the propagation of undesirable character traits in American society. One notable early proponent of eugenics was Harvey E. Jordan, dean of the School of Medicine at the University of Virginia and president of the American Genetic Association. The movement gained support from other prominent physicians including acclaimed urologist and birth control advocate William J. Robinson who wrote the early seminal books on contraception, including Eugenics, Marriage, and Birth Control in 1917. Although the first eugenic sterilization law was passed in Indiana in 1907, it was not until the Virginia Sterilization Act of 1924 that the practice of eugenic sterilization was codified as a legitimate medical practice. In its historic Buck v. Bell decision of 1927, the Supreme Court ruled that forced sterilization did not violate the 14th Amendment. The case centered around Carrie Buck in Charlottesville, VA who was deemed “defective” and “feebleminded” after being raped by the nephew of her foster parents. She was institutionalized after giving birth, and later sterilized in October 1927 as a result of the Supreme Court decision. Over the next four decades, the rate of eugenic sterilization soared nationwide. Estimates of the number of men and women undergoing forced vasectomies and salpingectomies in Virginia range from 7,300 to 8,300 between 1924 and 1979, with historical estimates of more than 60,000 sterilizations across the US. The American eugenics movement has been credited with lending inspiration to Adolf Hitler and the architects of the Holocaust. CONCLUSIONS: Virginia remained the last state to practice eugenic sterilization, repealing the statute in 1974. More than 3,000 forced vasectomies were performed in the state, and tens of thousands others across the country. The now infamous Buck v. Bell decision has yet to be overturned. Virginia Gov. Mark Warner issued a formal apology in 2002 for Virginia’s embrace of eugenics for more than five decades. Source of Funding: N/A © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e257 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Davis Moore More articles by this author Theodore Cisu More articles by this author Adam Klausner More articles by this author Expand All Advertisement PDF downloadLoading ...

Anthem for a Burnished Land: What We Leave in this Desert of Work and Words by Shaun T. Griffin

Reviewed by: Anthem for a Burnished Land: What We Leave in this Desert of Work and Words by Shaun T. Griffin Jeffrey Chisum Shaun T. Griffin, Anthem for a Burnished Land: What We Leave in this Desert of Work and Words. Cedar City: Southern Utah UP, 2016. 274 pp. Cloth, $30.95; paper, $17.95. Shaun T. Griffin is one of the luminaries of Nevada’s literary landscape: an inductee into the Nevada Writers Hall of Fame; author of the poetry books Bathing in the River of Ashes (1999) and Wood-smoke, Wind, and the Peregrine (2008), among others; editor of absolutely invaluable poetry collections such as Torn By Light (1993); and translator of Emma Sepulveda’s Muerte al silencio (1997). These literary endeavors alone would be enough to keep most people well occupied, but as Anthem for a Burnished Land demonstrates, Griffin’s contributions to Nevada life extend well beyond the written word. Subtitled “A Desert Memoir,” Anthem details Griffin’s involvement in a number of projects—struggles to found and maintain a community center in Virginia City; teaching poetry to prison inmates; a homeless youth education program. Throughout, daily life carries on: Griffin is married and has two children; we follow him along on a fishing excursion to Pyramid Lake; we watch his sometimes tense interactions with some of Virginia City’s more scurrilous residents. At times, Anthem seems to meander as though it needed a more cohesive narrative, but what eventually emerges is a complexly layered, episodic story about learning to cope with life in the Nevada desert. The opening passage, for example, describes the quality of sunlight on the Comstock: “It has changed everything: the rabbit brush is saffron, the locust seeps yellow, and the Virginia Range has a burnt tint . . . weather will change soon. You must prepare” (9). A later chapter describes the ever-present fear of fire: “Smoke has come into the room like an unwanted bird that has strayed from [End Page 486] its path. . . . This smoke is a terrible smell. No one who lives here has escaped its reach” (223). The natural landscape is both an inspiration for Griffin’s art and a cypher—a force that doesn’t readily supply a clear meaning. In the chapter called “American Flats,” Griffin provides imagery that’s both familiar and startling: “rusted lids, bed springs, bottles, shotgun shells, ceramic beer bottle shards, tin cans, barbed wire,” and while riding towards an aspen canyon, he sees “a rattlesnake [that] had swallowed all but the last of a baby rabbit” (162). “It took me a long time to notice such things,” he continues. The landscape “is a metaphor for the quiet and calm as much as it is for progress and desolation. It is a metaphor for those of us who live with this contradiction” (163). Griffin confronts this with a cheerfulness and enthusiasm that runs through the entire book. Despite moments of ruefulness—the deaths of loved ones, financial setbacks to the work in the community—Griffin maintains an optimism that is infectious. Perhaps the sustaining force in the book is art itself—Griffin’s own art (and there are numerous moments of arresting beauty in Anthem), his friends’, and his students’. In the chapter “Learning from Artists,” he describes the watercolor work of a Silver City painter named Karen Kreyeski, who supplied images for his first poetry book, Snowmelt (1994): The visual images were crisp and sensual. She made this landscape appear as if it were a human figure, a woman’s torso entwined in the snowmelt. The moon was a pale purple, rising in the half-light of dusk. The flanks of the mountains were blue and flecked with red watercolor pencil. She rendered the place of my awakening for the cover of this book. (55) Elsewhere, drawing upon the dual meaning (given the context) of the word “sentence,” Griffin describes the epiphanic reaction of his prisoner students to Ken Brewer’s Whale Song: A Poet’s Journey into Cancer (2007): “This, I imagine, is what Ken Brewer had hoped for: to scramble the alphabet of cancer and save one person from its sentence” (64). In the end, Anthem for a Burnished Land...

The Extirpation of Orconectes limosus (Spinycheek Crayfish) Populations in West Virginia

Abstract Introductions of nonnative crayfish species have resulted in the global decline of native crayfish populations, including those in North America. Historically, the North American range of Orconectes limosus (Spinycheek Crayfish) extended from Maine, southward into northern Virginia, including West Virginia's eastern panhandle. A 1988–1989 survey of the eastern panhandle of West Virginia resulted in the capture of only 14 O. limosus, but an abundance of the nonnative Orconectes virilis (Virile Crayfish). These data along with additional unpublished accounts of declines of O. limosus populations prompted our survey of eastern West Virginia. In 2005 and 2006, crayfishes were collected from streams within the West Virginia range of the O. limosus, including historic capture locations. Our collection of 600 individuals comprised crayfishes from 3 species: O. virilis, Orconectes obscurus (Allegheny Crayfish), and Cambarus bartonii bartonii (Common Crayfish). The nonnative O. virilis was present at 26 o...

Analysis of Energy Conservation Opportunities in Glass Manufacturing Facilities

ABSTRACT This article describes the nature of the energy conservation opportunities (ECOs) found in glass manufacturing facilities. The most significant ECOs are related to insulation of heat generating surfaces, preheating the combustion air in boilers, and heat recovery and distribution. The nature of the manufacturing activities found in the glass manufacturing facilities in the states of West Virginia and Pennsylvania range from glass decorating using purchased glass to manufacturing glass from basic raw materials using the hand blown or machine based processes. The Industrial Assessment Center at West Virginia University has conducted the energy assessments at the glass manufacturing facilities between 1996 and 1999 [22,23]. The nature of the glass manufacturing plants where these ECOs were determined are described based on plant groupings reported in [10]. It is interesting to note that energy savings of 280,000 MMBtu, and a cost savings of $ 1,080,000 were determined, resulting in a payback on inve...

Quartz-alunite alteration in the western part of the Virginia Range, Washoe and Storey counties, Nevada

Large areas of Miocene volcanic rocks in the western part of the Virginia Range, Washoe and Storey Counties, Nevada, were altered to quartz, alunite, and clay-dominated mineral assemblages, and all significant precious metal and mercury deposits throughout the range, including the Comstock Lode, Ramsey, and Talapoosa districts, occur in or adjacent to extensively altered andesites and dacites of the Miocene Alta and Kate Peak Formations. Radioisotopic analyses of alunite and precious metal vein minerals bracket the ages of quartz-alunite alteration at approximately 16 to 9 Ma, and vein mineralization at approximately 14 to 10 Ma, closely corresponding to Kate Peak Formation eruptive rock ages that range from approximately 15 to 10 Ma. Oxygen, deuterium, and sulfur isotope analyses of alunite, quartz, and water extracted from fluid inclusions in quartz-alunite altered rocks in the western part of the Virginia Range, and fluid inclusion microthermometry, show that the altering fluids were composed of magmatic water and mixtures of meteoric and magmatic water, and that the alteration took place in the temperature range approximately 205 degrees to 265 degrees C. Fluid inclusion water isotopic analyses indicate that Comstock Lode district veins were also deposited by a mixed magmatic-meteoric water fluid, and that subsurface altered intrusions, such as the molybdenite-bearing diorite in the Washington Hill alteration zone, can be identified by isotopic analyses of water in surface samples. Sources and thermal characteristics of fluids involved in quartz-alunite alteration and gold mineralization in the Ramsey district, similar to that at Goldfield, Nevada, and for other deposits in the Virginia Range, have not been determined, but mixingof magmatic and meteoric water at moderate hydrothermal temperatures may have been important in localizing ore.

New Miocene mammalian faunas from west central Nevada

Four new fossil mammalian assemblages are now recognized from west central Nevada. The late Barstovian or earliest Clarendonian Eagle-Picher Mine Site assemblage was recovered from the upper sedimentary member of the ?Desert Peak Formation exposed in the northeastern Virginia Range of Storey County and consists of the following taxa; Camelidae, gen. indet. and Rhinocerotidae, gen. indet. The ?Clarendonian Churchill Valley Local Fauna and Clarendonian or Hemphillian Churchill Narrows Site assemblage were recovered from correlatives of the type Coal Valley Formation exposed along the southern flanks of the Virginia Range and in the vicinity of the Churchill Narrows area, respectively. The Churchill Narrows Site assemblage consists of the following taxa: Rhinocerotidae, gen. indet.; Camelidae, gen. indet. (small-sized); and Camelidae, gen. indet. (large-sized). The Churchill Valley Local Fauna consists of the following taxa: Leporidae, gen. indet.; cf. Mustelidae, gen. indet.;Teleocerassp. indet.;Dinohippussp. indet.; Camelidae, gen. indet. (small-sized); and Camelidae, gen. indet. (large-sized). The late Hemphillian Silver Springs Local Fauna was recovered from outcrops of the Truckee Formation exposed in the southeastern Virginia Range of Lyons and Churchill counties. It is the first biostratigraphically datable fauna from the upper member of the formation and consists of the following taxa:Lepoidescf.lepoides; Hypolagus ringoldensis; Hypolagus tedfordi; Hypolagussp.;Pliotaxideasp. indet;Teleocerassp. indet.;Dinohippussp. indet.;Hemiauchenia vera;Camelidae, gen. indet. (medium-sized); and Antilocapridae, gen. indet.

Predicting potential transpiration of singleleaf pinyon: an adaptation of the potometer method

Estimates of singleleaf pinyon ( Pinus monophylla Tort. and Frem.) potential water use were conducted on the Virginia Range, Nevada, based on crown dimensions and needle biomass. A modified potometer method was developed to measure whole-tree transpiration over an 8 h period. Water uptake from the potometer was positively related to both the foliar mass plus the average number of resin canals in the needles of each tree. Water uptake was also positively related to the total crown needle surface area (cm 2) plus the average resin canal number. Best predictive equations based on standard error of the estimate analyses were obtained with nonlinear regression analysis of untransformed data. Pinyon populations with higher resin canal numbers are generally found in locations with higher temperatures and drier summer conditions.

Geology of Reno and Truckee Meadows, Nevada, United States of America

Reno, situated within the Truckee Meadows, just a few miles east of the California state line, is located between two markedly different physiographic provinces. One province is the Sierra Nevada (to the west), a region characterized with high mountains and heavy winter snow. To the east is the semi-arid Basin and Range province. Consequently, Reno, and the surrounding area, contains a diverse geology and a highly varied and interesting suite of geotechnical challenges, which greatly influence land-use considerations in this rapidly growing urban area. Reno owes its origins to the immigrant trails from the Midwest to California in the 18409s and to the Comstock Lode silver discovery in the nearby Virginia Mountains, in the 18509s. Officially, it9s existence began in 1868, with the arrival of the Central Pacific Railroad and the need for a station to join with the future Virginia and Truckee Railroad to service the Comstock Lode. Truckee Meadows is a fault-bounded basin surrounded by mountain ranges composed mainly of Tertiary volcanic rocks and inliers of pre-Tertiary volcanic and granitic rocks. The Virginia Range, to the east, is composed entirely of hydrothermally altered Oligocene and Miocene volcanic rocks forming the famous Comstock silver mining district. On the west, the Carson Range segment of the Sierra Nevada is composed largely of Tertiary volcanic rocks, overlying older granites, granodiorites, and metamorphic rocks. A thick sequence (in excess of 330 m [1,000 ft]), of glacial-fluvio, alluvial fan, and lacustrine deposits of late Tertiary to Quaternary age underlies the Truckee basin. At the southern end of the Truckee Meadows is located Steamboat Hot Springs, which has been utilized for commercial and recreational purposes since the 18609s. Presently three small (12.5, 7 and 5.5 MW) electric power plants make use of this geothermal resource. Seismologically active, Reno lies along the northern segment of the Sierra Nevada fault zone, a series of north-south trending faults, separating the Sierra Nevada from the Great Basin. Fault movement is predominantly dip-slip, based on surface displacements, although focal plane solutions suggest a component of strike-slip motion. No large magnitude earthquakes (MS>7) have been noted in the Reno area during historic time. However, several moderate-sized earthquakes with surface rupture events were associated with the 1869, 1950, and 1966 events. Long-term recurrence intervals for large-magnitude earthquakes on this segment of the Sierra Nevada fault zone are believed to be of the order of several thousand years. Several rock and soil formations pose potential geotechnical problems or hazards. Foundation problems related to expansive soils are mainly due to the hydrothermal alteration of andesites of the Alta Formation and surface weathering of other volcanic rocks. Floodplain and lacustrine deposits in the Truckee basin are composed of clayey silts, silty sands and large areas of fine sands which are susceptible to liquefaction where the ground-water surface is close to the topographic surface. Two major slope stability hazards in the hills surrounding the basin are recognized: rockfall from the well-jointed and slabby volcanic units and debris flows in the weathered rock, lahars, and surficial deposits which mantle the hill slopes. Major slope instability is restricted to steeper hill slopes and the Truckee River canyon. Snow avalanche hazards exist in the winter on the highways leading from Reno to Lake Tahoe and into California. Flash floods and floodplain hazards are historically a common occurrence. These events are due to severe summer thunderstorms, heavy spring rains, or rapidly melting snow packs. Even though a 1963 channelization of the Truckee River has reduced the hazard, over $16 million dollars of flood-related damage occurred as recently as 1986. Numerous small and large-scale metal mines exist in the hills surrounding Reno, producing cinnabar, lead, silver and gold. The mines are now inactive but their presence produces mine-related hazards of ground subsidence or the dramatic and rapid collapse of their shafts, especially where workings underlie buildings and other structures. In common with many other cities in the west, a dependable and adequate water supply is at a premium. Reno9s water reservoir is the winter snow pack of the Sierra Nevada, which, in a good year, can exceed 1,000 cm (± 480 in.). The Truckee River is fed from snowmelt and Reno derives its water either directly from the river or from wells in the alluvium which borders the river. Overall water quality is good, but localized geothermal discharges can adversely affect ground-water quality. Solid waste, in excess of 220 tonnes (1,200 tons)/day, is placed in two sanitary landfills east of the city. Liquid aqueous waste requires special handling and after waste-water treatment, its sludge is taken to one of the landfills.

Thermal infrared spectra and images of altered volcanic rocks in the Virginia Range, Nevada

Abstract Airborne Thermal Infrared Multispectral Scanner (TIMS) data and laboratory thermal infrared reflectance spectra were collected from sites of hydrothermally altered andesitic volcanic rocks near Virginia City, Nevada. Alunitic, kaolinitic, illitic, and propylitic alteration types have distinct laboratory spectral curves, although the individual spectra are difficult to interpret mineralogically. TIMS emittance spectra show a general shift in the wavelength of the silicate emittance minima to shorter wavelengths with increasing intensity of alteration, owing to the increasing abundance of secondary framework and sheet silicate minerals. Strongly altered volcanic rocksare identifiable on TIMS radiance and emittance imagery.

Chronology of Miocene hydrothermal and igneous events in the western Virginia Range, Washoe, Storey, and Lyon counties, Nevada

Chronology of Miocene hydrothermal and igneous events in the western Virginia Range, Washoe, Storey, and Lyon counties, Nevada

Estimation of the vegetation contribution to the 1·65/2·22 μm ratio in airborne thematic-mapper imagery of the Virginia Range, Nevada

Abstract Previous investigations have successfully used the 1·65/2·22μm ratio to map the concentration of hydroxyl-bearing minerals in imagery of sparsely vegetated terrain. However, difficulties arise in applying this ratio to semiarid regions where there is a wide variation in vegetation density. Besides mapping the mineralogic features of interest, the 1·65/2·22μm ratio also maps the density of vegetation by responding to leaf water content. A technique has been developed to estimate the vegetation contribution to this ratio based on the near-IR/red ratio. The technique has proved useful in mapping supergene alteration in the Virginia Range, Nevada

Coal in West Virginia: Geology and Current Mining Trends: ABSTRACT

Coal measures of West Virginia range in age from earliest Pennsylvanian to Permian. The state is divided into southern and northern coalfields or basins separated by a zone termed the hinge line. Deposition of the coal measures in the southern basin occurred under conditions of rapid subsidence, while deposition in the northern basin occurred on a relatively stable platform. End_Page 1287------------------------------ The hinge line appears to mark the northern limit of a series of growth faults that account for much of the subsidence in the southern basin. Coal production in 1979 was 113,793,868 short tons (85,697,048 short tons in 1978), according to the West Virginia Department of Mines Annual Report. Estimated remaining recoverable reserves total 57,139,067,471 short tons. The West Virginia Geological and Economic Survey is involved in a 10-year program to remap coal seams and map mines to obtain more accurate estimates of remaining reserves throughout the state. A great number of coal samples are being collected and analyzed; most analyses are available to the public and will be used to map coal-quality parameters. Mining has proceeded from outcrops of thick, high-quality coals near early railroads and navigable waterways to areas where the coal is thin, deep, impure, or relatively far from surface transportation facilities. Recently, exploration and development have occurred in the hinge-line area, traditionally regarded as relatively barren. End_of_Article - Last_Page 1288------------

STRUCTURAL SIGNIFICANCE OF GRAVITY SURVEYS IN THE VIRGINIA CITY—MOUNT ROSE AREA, NEVADA AND CALIFORNIA

Gravity surveys were made in the Mount Rose and Virginia City quadrangles to investigate the concealed Cenozoic structure of the alluviated basins and to explore for significant gravity differences between basins and ranges. The gravity data have been computed as complete Bouguer anomalies, which incorporate corrections for all the accurately assessible factors affecting gravity values, including topographic irregularities but not isostatic compensation. Gravity variations in the basins are closely related to changes in thickness of Cenozoic sedimentary rocks and alluvium in the basins. The gravity data indicate that light Cenozoic sedimentary rocks in Washoe Valley are at least 1800 feet thick; that the sediments in the northern part of Steamboat Valley are only about 600 feet thick and thin gradually eastward but thin abruptly to the west near Steamboat Hills; that east of Reno, between Sparks and the Virginia Range, sediments are roughly 2800 feet thick and thin abruptly about half a mile west of the range; and that in the basin west of Reno sediments are locally 1800 feet or more thick. The variations in thickness reflect important structural deformation in the basins. The late Cenozoic structures that separate the basins from the mountains are a complex of contemporaneous faults and folds; folding is predominant in some areas and normal faulting in others. From the eastern boundary of the area surveyed, the gravity values decrease westward about 1 mgal per mile, a total of 30 mgals, to a minimum at the east side of the Carson Range of the Sierra Nevada and then increase toward the main Sierra block. There is little or no gravity expression of the Virginia Range or the Carson Range relative to sediment-free parts of the basins adjacent to the ranges. Gravity measurements of the Coast and Geodetic Survey combined with the present measurements demonstrate that the Bouguer anomaly from San Francisco eastward shows a general inverse relationship to elevation but is a minimum along the east side of the Carson Range rather than at the main summit of the Sierra. This gravity profile may be the result of a thickening of the earth9s crust eastward beneath the higher part of the continent, combined with a smaller effect from greater-than-average amounts of granitic rock in the crust of the Sierran region.

Vegetation and Plant Growth as Affected by Chemically Altered Rocks in the Western Great Basin

During a preliminary survey of the vegetation of the western Great Basin, numerous isolated patches of yellow pine (Pinus ponderosa and P. jeffreyi) 2 were observed in the sagebrush and pinyonjuniper zones some distance to the east of the pine forests of the Sierra Nevada. Unlike the usual postclimax extensions of forest into grassland or brush, most of these groves are on hill-sides or ridgetops. They are remarkable also for their uniformly light yellowish soil which contrasts sharply with the brownish soils of the surrounding sagebrush or pinyonjuniper matrices. Further investigations have revealed more than 125 of these pine stands scattered along the Virginia Range and the eastern foothills of the Sierra. The majority occur on hillsides facing the Truckee Meadows, a graben between the Carson Range and the Virginia Range, in southern Washoe County, Nevada. Outlying stands are present as far north as Long Valley, Lassen County, California, and as far south as Colorado Hill, Alpine County, California. The eastern limit seems to be set by groves at the old mining camp of Ramsey in the Virginia Range, about 25 miles east of Reno, Nevada, and by an extensive stand on the northwest side of Pah-Rah Mountain near Pyramid Lake. Since the stands range in elevation from about 4,300 feet to over 7,000 feet and from the slopes of the Carson Range to the east side of the Virginia Range,