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Articles 631 - 660 of 691
Full-Text Articles in Earth Sciences
A Detailed Petrographic Analysis Of The Mt. Sheridan Roosevelt Gabbro And Associated Rock Types, Daniel Russell Lasco
A Detailed Petrographic Analysis Of The Mt. Sheridan Roosevelt Gabbro And Associated Rock Types, Daniel Russell Lasco
Masters Theses
"The Mt. Sheridan Roosevelt Gabbro of the Wichita Mountains igneous province in Southwestern Oklahoma underwent dynamic crystallization, resulting in three distinct gabbro zones with a range of pegmatite morphologies spread throughout. The three zones are informally named the lower, central, and upper zones. The lower zone consists of a quartz and alkali feldspar poor, plagioclase and pyroxene rich, poorly altered, gabbro cumulate. The central zone is comprised of a heavily altered quartz and alkali feldspar rich gabbro with few cumulate textures. The upper zone is mineralogically and texturally identical to the lower zone, distinguished only by its higher elevation. The …
Eogenetic Caves In Conglomerate: An Example From Udin Boršt, Slovenia, Matej Lipar, Mateja Ferk
Eogenetic Caves In Conglomerate: An Example From Udin Boršt, Slovenia, Matej Lipar, Mateja Ferk
International Journal of Speleology
Udin Boršt is a karstified terrace of carbonate rock, which is of fluvioglacial origin, and is situated in the north-western part of Slovenia. There are 15 registered caves, which have been interpreted as caves in conglomerate, while karst of Udin Boršt itself was interpreted as conglomerate karst, shallow karst or isolated karst. In this article, caves in Udin Boršt have been interpreted as eogenetic caves. Based on porosity and bedding material, different types of caves and cave passages have developed. Four general types of eogenetic caves found in Udin Boršt are; linear stream caves, shelter caves, breakdown caves and vadose …
Fungal Communities On Speleothem Surfaces In Kartchner Caverns, Arizona, Usa., Michael J. Vaughan, Raina M. Maier, Barry M. Pryor
Fungal Communities On Speleothem Surfaces In Kartchner Caverns, Arizona, Usa., Michael J. Vaughan, Raina M. Maier, Barry M. Pryor
International Journal of Speleology
Kartchner Caverns, located near Benson, Arizona, USA, is an active carbonate cave that serves as the major attraction for Kartchner Caverns State Park. Low-impact development and maintenance have preserved prediscovery macroscopic cavern features and minimized disturbances to biological communities within the cave.. The goal of this study was to examine fungal diversity in Kartchner Caverns on actively-forming speleothem surfaces. Fifteen formations were sampled from five sites across the cave. Richness was assessed using standard culture-based fungal isolation techniques. A culture-independent analysis using denaturing gradient gel electrophoresis (DGGE) was used to assay evidence of community homogeneity across the cave through the …
A New Foodweb Based On Microbes In Calcitic Caves: The Cansiliella (Beetles) Case In Northern Italy, Maurizio G. Paoletti, Mattia Beggio, Angelo Leandro Dreon, Alberto Pamio, Tiziano Gomiero, Mauro Brilli, Luca Dorigo, Giuseppe Concheri, Andrea Squartini, Annette Summers Engel
A New Foodweb Based On Microbes In Calcitic Caves: The Cansiliella (Beetles) Case In Northern Italy, Maurizio G. Paoletti, Mattia Beggio, Angelo Leandro Dreon, Alberto Pamio, Tiziano Gomiero, Mauro Brilli, Luca Dorigo, Giuseppe Concheri, Andrea Squartini, Annette Summers Engel
International Journal of Speleology
The troglobitic beetle, Cansiliella servadeii percolating water on moonmilk, a speleothem formation in Grotta della Foos, Italy. Results from analyses of stable isotopes of carbon and nitrogen suggest that acquires and assimilates dissolved allochthonous organic carbon, inorganic nitrogen, and possibly phosphorus and other nutrients from the microbial fauna associated with moonmilk.
Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban
Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban
International Journal of Speleology
Cioclovina Cave in Romania’s Southern Carpathians is a world-renowned cave site for its paleontological, anthropological, and mineralogical (type locality of ardealite) findings. To date, over 25 mineral species have been documented, some unusual for a cave environment. This paper presents details on the occurrence of collinsite [Ca2(Mg,Fe2+)(PO4)2·2H2O], atacamite [Cu22+Cl(OH)3], and kröhnkite [Na2Cu2+(SO4)2·2H2O] based on single-crystal X-ray diffraction, electron microprobe, stable isotope analyses, and scanning electron microscope imaging. This is the first reported occurrence of kröhnkite …
Minerogenetic Mechanisms Occurring In The Cave Environment: An Overview, Bogdan P. Onac, Paolo Forti
Minerogenetic Mechanisms Occurring In The Cave Environment: An Overview, Bogdan P. Onac, Paolo Forti
International Journal of Speleology
Perhaps man’s first motivation to explore caves, beyond using them as shelter, was the search for substances that were not available elsewhere: most of them were minerals. However, for a long time it was believed that the cave environment was not very interesting from the mineralogical point of view. This was due to the fact that most cave deposits are normally composed of a single compound: calcium carbonate. Therefore, the systematic study of cave mineralogy is of only recent origin. However, although only a limited number of natural cavities have been investigated in detail, about 350 cave minerals have already …
Trace Element And Stable Isotope Data From A Flowstone In A Natural Cave Of The Mining District Of Sw Sardinia (Italy): Evidence For Zn²⁺-Induced Aragonite Precipitation In Comparatively Wet Climatic Conditions, Guglielmo Angelo Caddeo, Jo De Waele, Franco Frau, Loren Bruce Railsback
Trace Element And Stable Isotope Data From A Flowstone In A Natural Cave Of The Mining District Of Sw Sardinia (Italy): Evidence For Zn²⁺-Induced Aragonite Precipitation In Comparatively Wet Climatic Conditions, Guglielmo Angelo Caddeo, Jo De Waele, Franco Frau, Loren Bruce Railsback
International Journal of Speleology
A speleothem from Crovassa Azzurra, a mine cave in SW Sardinia (Italy), has been analysed for mineralogy, minor and trace elements and stable isotopes. It is composed of layers of primary calcite and aragonite, with a region of secondary calcite. The primary carbonate is strikingly rich in Zn and Pb, presumably as the result of transport in solution from overlying Pb-Zn deposits. Immediately below the transition between calcite and aragonite, concentrations of Zn, Cd and P increase. At the transition between aragonite and Pb-rich aragonite, concentrations of Pb and P increase. Stable isotopes indicate an evolution toward more humid periods …
Minerals And Speleothems Of The József-Hegy Cave (Budapest, Hungary), Szabolcs Leél-Őssy, Gyöngyvér Szanyi, Gergely Surányi
Minerals And Speleothems Of The József-Hegy Cave (Budapest, Hungary), Szabolcs Leél-Őssy, Gyöngyvér Szanyi, Gergely Surányi
International Journal of Speleology
With the discovery of the József-hegy Cave, a cave of hydrothermal origin with an abundance of minerals unknown so far in Hungary came to light. Diversity and the frequency of the occurrence of crystals make this cave similar to the Lechuguilla Cave, even if the dimensions of the mineral precipitations and the passages do not compare in scale. The variety and mass of carbonates and sulphates are surprising. This paper describes the minerals and speleothems of the József-hegy Cave, their occurrence and genesis, including determined ages. The 41 U/Th measurements suggest that speleothems begun to develop in the upper level …
Potential For Speciation In Mammals Following Vast, Late Miocene Volcanic Interruptions In The Pacific Northwest, Ryan Thomas Mckenna
Potential For Speciation In Mammals Following Vast, Late Miocene Volcanic Interruptions In The Pacific Northwest, Ryan Thomas Mckenna
Dissertations and Theses
The impact of large-scale volcanic eruptions on landscapes can affect many processes ranging from interrupting or redirecting regional soil forming processes and hydrological systems to generating temporary changes in global climate. Though more studies exist every year, less is known of the direct impact of large-scale volcanic eruptions on ecosystems and extinction, while even less is known of their impact on speciation. In deposits throughout the Pacific Northwest a special combination and association of volcanic magnitude with palaeoecological yield frequently presents unique prospects for inquiry. In this study, particular attention is given to large, late Miocene ash-flow tuffs of central …
A Note On The Occurrence Of A Crayback Stalagmite At Niah Caves, Borneo, Joyce Lundberg, Donald A. Mcfarlane
A Note On The Occurrence Of A Crayback Stalagmite At Niah Caves, Borneo, Joyce Lundberg, Donald A. Mcfarlane
International Journal of Speleology
Crayback stalagmites have mainly been reported from New South Wales, Australia. Here we document a small crayback in the entrance of Painted Cave (Kain Hitam), part of the Niah Caves complex in Sarawak, Borneo. Measuring some 65 cm in length and 18 cm in height, this deposit is elongate in the direction of the dominant wind and thus oriented towards the natural tunnel entrance. It shows the classic humpbacked long profile, made up of small transverse segments or plates, in this case the tail extending towards the entrance. The dark blue-green colour down the centre suggests that cyanobacterial growth follows …
The Present Day Genesis And Evolution Of Cave Minerals Inside The Ojo De La Reina Cave (Naica Mine, Mexico), Giovanni Badino, José Maria Calaforra, Paolo Forti, Paolo Garofalo, Laura Sanna
The Present Day Genesis And Evolution Of Cave Minerals Inside The Ojo De La Reina Cave (Naica Mine, Mexico), Giovanni Badino, José Maria Calaforra, Paolo Forti, Paolo Garofalo, Laura Sanna
International Journal of Speleology
Ojo de la Reina is the first and the smallest cave intersected at the -290 level in the Naica Mine (Mexico), therefore it was the first cavity in which the lowering of temperature induced by mine ventilation caused condensation over crystals’ surface since 2005. The consequent dissolution of the gypsum crystals and subsequent condensed water evaporation lead to the deposition of several new minerals, among which some highly soluble Mg/Na compounds (bloedite, epsomite, halite, hexahydrite, kieserite, starkeyite). The single available source of Mg and Na ions in this minerogenetic environment is represented by the huge fluid inclusions widespread within the …
Black Mn-Fe Crusts As Markers Of Abrupt Palaeoenvironmental Changes In El Soplao Cave (Cantabria, Spain), Fernando Gázquez, Jose Maria Calaforra, Paolo Forti
Black Mn-Fe Crusts As Markers Of Abrupt Palaeoenvironmental Changes In El Soplao Cave (Cantabria, Spain), Fernando Gázquez, Jose Maria Calaforra, Paolo Forti
International Journal of Speleology
Peculiar iron and manganese deposits coating walls, floors and ceilings of many galleries are one of the special features of the El Soplao Cave (Cantabria, Spain). These speleothems appear to have been deposited over wall clay deposits, as well as forming part of flowstones. Structure of crusts is essentially amorphous but several manganese and iron oxides were identified like goethite and birnessite, though all occur with a low degree of crystallinity. In the outer layer of the crusts, alteration iron minerals appear that derive from previous minerals in a process probably mediated by microorganisms. EDX microanalyses report fairly high values …
Mineralogy Of Iza Cave (Rodnei Mountains, N. Romania), Tudor Tămaş, Ferenc Kristály, Lucian Barbu-Tudoran
Mineralogy Of Iza Cave (Rodnei Mountains, N. Romania), Tudor Tămaş, Ferenc Kristály, Lucian Barbu-Tudoran
International Journal of Speleology
The secondary minerals from Iza Cave result from the interactions of karst water and/or cave atmosphere over a variety of sedimentary and metamorphic rocks. The cave passages expose at various extents Eocene limestones and conglomerates, Oligocene black shales, Upper Precambrian micaschists, marble and dolomitic marble and associated ore deposits.
Twelve secondary minerals identified in the cave (carbonates, sulfates, phosphates, oxides and hydroxides, and silicates) are presented in this study. Calcite, aragonite, gypsum, brushite and hydroxylapatite are the components of common speleothems in the limestone, dolomite and conglomerate areas of the cave. Ankerite crusts are related to areas with pyrite mineralization …
Comparison Of 14c And U-Th Ages Of Two Holocene Phreatic Overgrowths On Speleothems From Mallorca (Western Mediterranean): Environmental Implications, Paola Tuccimei, Mark Van Strydonck, Angel Ginés, Joaquín Ginés, Michele Soligo, Igor M. Villa, Joan J. Fornós
Comparison Of 14c And U-Th Ages Of Two Holocene Phreatic Overgrowths On Speleothems From Mallorca (Western Mediterranean): Environmental Implications, Paola Tuccimei, Mark Van Strydonck, Angel Ginés, Joaquín Ginés, Michele Soligo, Igor M. Villa, Joan J. Fornós
International Journal of Speleology
This investigation reports on the comparison between ICP-MS U-Th and AMS 14C ages of Phreatic Overgrowths on Speleothems (POS) from two different caves on the island of Mallorca (Spain). These speleothem encrustations form at the water table of coastal caves in a low-amplitude tide-controlled microenvironment and are used to reconstruct past sea level changes. The aim of this study is to evaluate if this particular type of speleothem is datable using 14C method and to investigate possible problems connected with the incorporation of dead carbon inherited from the dissolution of 14C-free limestone. The results show that 14C ages are strongly …
A Comparative Integrated Geophysical Study Of Horseshoe Chimney Cave, Colorado Bend State Park, Texas, Wesley A. Brown, Kevin W. Stafford, Mindy Shaw-Faulkner, Andy Grubbs
A Comparative Integrated Geophysical Study Of Horseshoe Chimney Cave, Colorado Bend State Park, Texas, Wesley A. Brown, Kevin W. Stafford, Mindy Shaw-Faulkner, Andy Grubbs
International Journal of Speleology
An integrated geophysical study was performed over a known cave in Colorado Bend State Park (CBSP), Texas, where shallow karst features are common within the Ellenberger Limestone. Geophysical survey such as microgravity, ground penetrating radar (GPR), direct current (DC) resistivity, capacitively coupled (CC) resistivity, induced polarization (IP) and ground conductivity (GC) measurements were performed in an effort to distinguish which geophysical method worked most effectively and efficiently in detecting the presence of subsurface voids, caves and collapsed features. Horseshoe Chimney Cave (HCC), which is part of a larger network of cave systems, provides a good control environment for this research. …
Evolution Of The Veternica Cave (Medvednica Mountain, Croatia) Drainage System: Insights From The Distribution And Dating Of Cave Deposits, Damir Lacković, Bosiljka Glumac, Yemane Asmerom, Andrej Stroj
Evolution Of The Veternica Cave (Medvednica Mountain, Croatia) Drainage System: Insights From The Distribution And Dating Of Cave Deposits, Damir Lacković, Bosiljka Glumac, Yemane Asmerom, Andrej Stroj
Geosciences: Faculty Publications
Detailed field examination, U-Th age dating, and stable isotope analysis of Veternica flowstone and shelfstone deposits have been employed in order to unravel details about the geological history of Veternica Cave (Medvednica Mountain, Croatia). The study was carried out in the hydrologically inactive part of the main cave channel, which is developed mainly along the unconformity between Triassic dolostone and Miocene limestone. For 180 m from the cave entrance, (located at 320 metres above sea level (asl)), the morphology of the main channel reflects exclusively phreatic conditions in the cave until the end of its hydrological activity. From 180 to …
Stratigraphy And Petroleum Production Potential Of The Spearfish Formation In North Central North Dakota, Nnaemeka C. Anyanwu
Stratigraphy And Petroleum Production Potential Of The Spearfish Formation In North Central North Dakota, Nnaemeka C. Anyanwu
Theses and Dissertations
The Spearfish oil play is unconventional requiring the use of horizontal wells that are fracture stimulated to deliver economic flow rates. However, fraccing into the underlying water has been a source of significant production problems for operators. The key to developing the area is to keep the individual fracs large enough to stimulate the tight Spearfish sands but not to let them propagate into the underlying water zone.
The Spearfish Formation of the Black Hills has been traced into the subsurface of the Williston Basin in western North Dakota from bore holes at the northern margin of the outcrop area …
Identifying Potential Geothermal Resources From Co-Produced Fluids Using Existing Data From Drilling Logs : Williston, North Dakota, Anna M. Crowell
Identifying Potential Geothermal Resources From Co-Produced Fluids Using Existing Data From Drilling Logs : Williston, North Dakota, Anna M. Crowell
Theses and Dissertations
With the current need for technology that will allow for environmentally-friendly power generation, geothermal power has become an attractive resource given its low environmental impact and potential cost savings. One specific resource is co-produced water from oil wells that are not currently producing, but can yield formation waters that are both high enough in temperature and fluid volume to operate the turbines of binary geothermal power systems. The data required to identify sites, i.e. bottom-hole temperatures (BHT), latitude, longitude, total depth of hole (TD) in meters, the identification number, and the amount of water produced in gallons, can be mined …
Evaluating Spawning Migration Patterns And Predicting Spawning Success Of Shovelnose Sturgeon In The Lower Missouri River, M. L. Wildhaber, S. H. Holan, G. M. Davis, D. W. Gladish, A. J. Delonay, Diana M. Papoulias, D. K. Sommerhauser
Evaluating Spawning Migration Patterns And Predicting Spawning Success Of Shovelnose Sturgeon In The Lower Missouri River, M. L. Wildhaber, S. H. Holan, G. M. Davis, D. W. Gladish, A. J. Delonay, Diana M. Papoulias, D. K. Sommerhauser
United States Geological Survey: Staff Publications
Approaches using telemetry, precise reproductive assessments, and surgically implanted data storage tags (DSTs) were used in combination with novel applications of analytical techniques for fish movement studies to describe patterns in migratory behavior and predict spawning success of gravid shovelnose sturgeon. From 2004 to 2007, over 300 gravid female shovelnose sturgeon (Scaphirhynchus platorynchus) from the Lower Missouri River, that were expected to spawn in the year they were collected, were surgically implanted with transmitters and archival DSTs. Functional cluster modeling of telemetry data from the spawning season suggested two common migration patterns of gravid female shovelnose sturgeon. Fish …
Land Change Variability And Human–Environment Dynamics In The United States Great Plains, Mark A, Drummond, Roger F. Auch, Krista A. Karstensen, Kristi L. Sayler, Janis L. Taylor, Thomas Loveland
Land Change Variability And Human–Environment Dynamics In The United States Great Plains, Mark A, Drummond, Roger F. Auch, Krista A. Karstensen, Kristi L. Sayler, Janis L. Taylor, Thomas Loveland
United States Geological Survey: Staff Publications
Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km × 10 km blocks is used to efficiently identify the types and rates …
Introduction To “Environmental Contaminants In Biota, 2nd Edition”, W. Nelson Beyer, James P. Meador
Introduction To “Environmental Contaminants In Biota, 2nd Edition”, W. Nelson Beyer, James P. Meador
United States Geological Survey: Staff Publications
Ecotoxicology is the study of the movement of environmental contaminants through ecosystems and their effects on plants and animals. Examining tissue residues of these contaminants in biota is basic to ecotoxicology, both for understanding the movement of contaminants within organisms and through food chains, and for understanding and quantifying injuries to organisms and their communities. This book provides guidance on interpreting tissue concentrations of environmental contaminants.
Tissue concentrations have long been used both to identify the cause of toxicity in animals and as a measure of the severity of toxicity. More recently, they have been incorporated into environmental models, tying …
Spatial Patch Occupancy Patterns Of The Lower Keys Marsh Rabbit, Mitchell J. Eaton, Phillip T. Hughes, James D. Nichols, Anne Morkill, Chad Anderson
Spatial Patch Occupancy Patterns Of The Lower Keys Marsh Rabbit, Mitchell J. Eaton, Phillip T. Hughes, James D. Nichols, Anne Morkill, Chad Anderson
United States Geological Survey: Staff Publications
Reliable estimates of presence or absence of a species can provide substantial information on management questions related to distribution and habitat use but should incorporate the probability of detection to reduce bias. We surveyed for the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) in habitat patches on 5 Florida Key islands, USA, to estimate occupancy and detection probabilities. We derived detection probabilities using spatial replication of plots and evaluated hypotheses that patch location (coastal or interior) and patch size influence occupancy and detection. Results demonstrate that detection probability, given rabbits were present, was <0.5 and suggest that naı¨ve estimates (i.e., estimates without consideration of imperfect detection) of patch occupancy are negatively biased. We found that patch size and location influenced probability of occupancy but not detection. Our findings will be used by Refuge managers to evaluate population trends of Lower Keys marsh rabbits from historical data and to guide management decisions for species recovery. The sampling and analytical methods we used may be useful for researchers and managers of other endangered lagomorphs and cryptic or fossorial animals occupying diverse habitats.
Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link
Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link
United States Geological Survey: Staff Publications
Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models …
Adaptive Resource Management And The Value Of Information, Byron K. Williams, Mitchell J. Eaton, David R. Breininger
Adaptive Resource Management And The Value Of Information, Byron K. Williams, Mitchell J. Eaton, David R. Breininger
United States Geological Survey: Staff Publications
The value of information is a general and broadly applicable concept that has been used for several decades to aid in making decisions in the face of uncertainty. Yet there are relatively few examples of its use in ecology and natural resources management, and almost none that are framed in terms of the future impacts of management decisions. In this paper we discuss the value of information in a context of adaptive management, in which actions are taken sequentially over a time frame and both future resource conditions and residual uncertainties about resource responses are taken into account. Our objective …
Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link
Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link
United States Geological Survey: Staff Publications
Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models …
Spatial Patch Occupancy Patterns Of The Lower Keys Marsh Rabbit, Mitchell J. Eaton, Phillip T. Hughes, James D. Nichols, Anne Morkill, Chad Anderson
Spatial Patch Occupancy Patterns Of The Lower Keys Marsh Rabbit, Mitchell J. Eaton, Phillip T. Hughes, James D. Nichols, Anne Morkill, Chad Anderson
United States Geological Survey: Staff Publications
Reliable estimates of presence or absence of a species can provide substantial information on management questions related to distribution and habitat use but should incorporate the probability of detection to reduce bias. We surveyed for the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) in habitat patches on 5 Florida Key islands, USA, to estimate occupancy and detection probabilities. We derived detection probabilities using spatial replication of plots and evaluated hypotheses that patch location (coastal or interior) and patch size influence occupancy and detection. Results demonstrate that detection probability, given rabbits were present, was <0.5 and suggest that naı¨ve estimates (i.e., estimates without consideration of imperfect detection) of patch occupancy are negatively biased. We found that patch size and location influenced probability of occupancy but not detection. Our findings will be used by Refuge managers to evaluate population trends of Lower Keys marsh rabbits from historical data and to guide management decisions for species recovery. The sampling and analytical methods we used may be useful for researchers and managers of other endangered lagomorphs and cryptic or fossorial animals occupying diverse habitats.
Adaptive Resource Management And The Value Of Information, Byron K. Williams, Mitchell J. Eaton, David R. Breininger
Adaptive Resource Management And The Value Of Information, Byron K. Williams, Mitchell J. Eaton, David R. Breininger
United States Geological Survey: Staff Publications
The value of information is a general and broadly applicable concept that has been used for several decades to aid in making decisions in the face of uncertainty. Yet there are relatively few examples of its use in ecology and natural resources management, and almost none that are framed in terms of the future impacts of management decisions. In this paper we discuss the value of information in a context of adaptive management, in which actions are taken sequentially over a timeframe and both future resource conditions and residual uncertainties about resource responses are taken into account. Our objective is …
Comment On ‘‘An Unconfined Groundwater Model Of The Death Valley Regional Flow System And A Comparison To Its Confined Predecessor’’ By R.W.H. Carroll, G.M. Pohll And R.L. Hershey [Journal Of Hydrology 373/3–4, Pp. 316–328], Claudia C. Faunt, Alden M. Provost, Mary C. Hill, Wayne R. Belcher
Comment On ‘‘An Unconfined Groundwater Model Of The Death Valley Regional Flow System And A Comparison To Its Confined Predecessor’’ By R.W.H. Carroll, G.M. Pohll And R.L. Hershey [Journal Of Hydrology 373/3–4, Pp. 316–328], Claudia C. Faunt, Alden M. Provost, Mary C. Hill, Wayne R. Belcher
United States Geological Survey: Staff Publications
Carroll et al. (2009) state that the United States Geological Survey (USGS) Death Valley Regional Flow System (DVRFS) model, which is based on MODFLOW, is ‘‘conceptually inaccurate in that it models an unconfined aquifer as a confined system and does not simulate unconfined drawdown in transient pumping simulations.’’ Carroll et al. (2009) claim that ‘‘more realistic estimates of water availability’’ can be produced by a SURFACT-based model of the DVRFS that simulates unconfined groundwater flow and limits withdrawals from wells to avoid excessive drawdown. Differences in results from the original MODFLOW- based model and the SURFACT-based model stem primarily from …
Airborne Electromagnetic Surveys For 3d Geological Mapping, Jared D. Abraham, James C. Cannia
Airborne Electromagnetic Surveys For 3d Geological Mapping, Jared D. Abraham, James C. Cannia
United States Geological Survey: Staff Publications
The U.S. Geological Survey and its partners have collaborated to create 3D geologic maps for areas of the North and South Platte River valleys, including Lodgepole Creek, in western Nebraska using airborne electromagnetic surveys. The objective of the surveys is to map the 3D configuration of aquifers and bedrock topography created by the paleochannels of the ancestral Platte River. The ultimate goal is to gain a new understanding of groundwater–surface-water relationships to improve water management decisions through the use of groundwater management models. This goal was not achievable using traditional mapping methodologies, including surface geologic maps and borehole drilling logs. …
Evolution Of Large Carnivores During The Mid-Cenozoic Of North America: The Temnocyonine Radiation (Mammalia, Amphicyonidae) Robert M., Robert M. Hunt Jr.
Evolution Of Large Carnivores During The Mid-Cenozoic Of North America: The Temnocyonine Radiation (Mammalia, Amphicyonidae) Robert M., Robert M. Hunt Jr.
Department of Earth and Atmospheric Sciences: Faculty Publications
This study describes and summarizes the Temnocyoninae (Mammalia, Carnivora), a subfamily of amphicyonid carnivores of considerable diversity and singular ecomorphology within Cenozoic faunas of North America. In temnocyonines, we see the first carnivorans to occupy an ecological niche as large cursorial predators. The subfamily is confined to the Arikareean NALMA, ranging in age from the latest early Oligocene to the early Miocene. Distributed from the Pacific Northwest to the Great Plains and Florida, there are four genera (Temnocyon, Mammacyon, Delotrochanter n. gen., Rudiocyon n. gen.) and 12 species, of which eight are newly described (Temnocyon subferox …