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Full-Text Articles in Physical Sciences and Mathematics

Beyond Functional Diversity: The Importance Of Trophic Position To Understanding Functional Processes In Community Evolution, Roxanne M. W. Banker, Ashley A. Dineen, Melanie G. Sorman, Carrie L. Tyler, Peter D. Roopnarine Oct 2022

Beyond Functional Diversity: The Importance Of Trophic Position To Understanding Functional Processes In Community Evolution, Roxanne M. W. Banker, Ashley A. Dineen, Melanie G. Sorman, Carrie L. Tyler, Peter D. Roopnarine

Geoscience Faculty Publications

Ecosystem structure—that is the species present, the functions they represent, and how those functions interact—is an important determinant of community stability. This in turn a􀀀ects how ecosystems respond to natural and anthropogenic crises, and whether species or the ecological functions that they represent are able to persist. Here we use fossil data from museum collections, literature, and the Paleobiology Database to reconstruct trophic networks of Tethyan paleocommunities fromthe Anisian and Carnian (Triassic), Bathonian (Jurassic), and Aptian (Cretaceous) stages, and compare these to a previously reconstructed trophic network from a modern Jamaican reef community. We generated model food webs consistent with …


Numerical Modeling Of Mineralizing Processes During The Formation Of The Yangzhuang Kiruna-Type Iron Deposit, Middle And Lower Yangtze River Metallogenic Belt, China: Implications For The Genesis And Longevity Of Kiruna-Type Iron Oxide-Apatite Systems, Xunyu Hu, Simon Jowitt, Feng Yuan, Guangxian Liu, Jinhui Luo, Yuhua Chen, Hui Yang, Keyue Ren, Yongguo Yang Dec 2021

Numerical Modeling Of Mineralizing Processes During The Formation Of The Yangzhuang Kiruna-Type Iron Deposit, Middle And Lower Yangtze River Metallogenic Belt, China: Implications For The Genesis And Longevity Of Kiruna-Type Iron Oxide-Apatite Systems, Xunyu Hu, Simon Jowitt, Feng Yuan, Guangxian Liu, Jinhui Luo, Yuhua Chen, Hui Yang, Keyue Ren, Yongguo Yang

Geoscience Faculty Publications

The Yangzhuang iron deposit is a Kiruna-type iron oxide-apatite (IOA) deposit within the Ningwu mining district of the Middle and Lower Yangtze River Metallogenic Belt (MLYRMB), China. This study applies a numerical modeling approach to identify the key processes associated with the formation of the deposit that cannot be easily identified using traditional analytical approaches, including the duration of the mineralizing process and the genesis of iron orebodies within intrusions associated with the deposit. This approach highlights the practical value of numerical modeling in quantitatively analyzing mineralizing processes during the formation of mineral deposits and assesses how these methods can …


Shallow Rupture Propagation Of Pleistocene Earthquakes Along The Hurricane Fault, Ut, Revealed By Hematite (U-Th)/He Thermochronometry And Textures, Madison P. Taylor, Alexis K. Ault, Margaret L. Odlum, Dennis L. Newell Sep 2021

Shallow Rupture Propagation Of Pleistocene Earthquakes Along The Hurricane Fault, Ut, Revealed By Hematite (U-Th)/He Thermochronometry And Textures, Madison P. Taylor, Alexis K. Ault, Margaret L. Odlum, Dennis L. Newell

Geoscience Faculty Publications

The material properties and distribution of faults above the seismogenic zone promote or inhibit earthquake rupture propagation. We document the depths and mechanics of fault slip along the seismically active Hurricane fault, UT, with scanning and transmission electron microscopy and hematite (U-Th)/He thermochronometry. Hematite occurs as mm-scale, striated patches on a >10 m2 thin, mirror-like silica fault surface. Hematite textures include bulbous aggregates and cataclasite, overlain by crystalline Fe-oxide nanorods and an amorphous silica layer at the slip interface. Textures reflect mechanical, fluid, and heat-assisted amorphization of hematite and silica-rich host rock that weaken the fault and promote rupture propagation. …


Coupled Deep-Mantle Carbon-Water Cycle: Evidence From Lower-Mantle Diamonds, Wenzhong Wang, Oliver Tschauner, Shichun Huang, Zhongqing Wu, Yufei Meng, Hans Bechtel, Ho Kwang Mao May 2021

Coupled Deep-Mantle Carbon-Water Cycle: Evidence From Lower-Mantle Diamonds, Wenzhong Wang, Oliver Tschauner, Shichun Huang, Zhongqing Wu, Yufei Meng, Hans Bechtel, Ho Kwang Mao

Geoscience Faculty Publications

Diamonds form in a variety of environments between subducted crust, lithospheric and deep mantle. Recently, deep source diamonds with inclusions of the high-pressure H O-phase ice-VII were discovered. By correlating the pressures of ice-VII inclusions with those of other high-pressure inclusions, we assess quantitatively the pressures and temperatures of their entrapment. We show that the ice-VII-bearing diamonds formed at depths down to 800 ± 60 km but at temperatures 200–500 K below average mantle temperature that match the pressure-temperature conditions of decomposing dense hydrous mantle silicates. Our work presents strong evidence for coupled recycling of water and carbon in the …


Equation Of State For Natural Almandine, Spessartine, Pyrope Garnet: Implications For Quartz-In-Garnet Elastic Geobarometry, Suzanne R. Mulligan, Elissaios Stavrou, Stella Chariton, Oliver Tschauner, Ashkan Salamat, Michael Wells, Alexander G. Smith, Thomas D. Hoisch, Vitali Prakapenka Apr 2021

Equation Of State For Natural Almandine, Spessartine, Pyrope Garnet: Implications For Quartz-In-Garnet Elastic Geobarometry, Suzanne R. Mulligan, Elissaios Stavrou, Stella Chariton, Oliver Tschauner, Ashkan Salamat, Michael Wells, Alexander G. Smith, Thomas D. Hoisch, Vitali Prakapenka

Geoscience Faculty Publications

The equation of state (EoS) of a natural almandine74spessartine13pyrope10grossular3 garnet of a typical composition found in metamorphic rocks in Earth’s crust was obtained using single crystal synchrotron X-ray diffraction under isothermal room temperature compression. A third-order Birch-Murnaghan EoS was fitted to P-V data and the results are compared with published EoS for iron, manganese, magnesium, and calcium garnet compositional end-members. This comparison reveals that ideal solid solution mixing can reproduce the EoS for this intermediate composition of garnet. Additionally, this new EoS was used to calculate geobarometry on a garnet sample from the same rock, which was collected from the …


3d Numerical Simulation-Based Targeting Of Skarn Type Mineralization Within The Xuancheng-Magushan Orefield, Middle-Lower Yangtze Metallogenic Belt, China, Xunyu Hu, Xiaohui Li, Feng Yuan, Simon M. Jowitt, Alison Ord, Rui Ye, Yue Li, Wenqiang Dai, Xiangling Li Dec 2020

3d Numerical Simulation-Based Targeting Of Skarn Type Mineralization Within The Xuancheng-Magushan Orefield, Middle-Lower Yangtze Metallogenic Belt, China, Xunyu Hu, Xiaohui Li, Feng Yuan, Simon M. Jowitt, Alison Ord, Rui Ye, Yue Li, Wenqiang Dai, Xiangling Li

Geoscience Faculty Publications

Recent exploration has identified a series of Cu-Mo skarn deposits within the Xuancheng-Magushan orefield. The orefield forms part of the Nanling-Xuancheng mining district, which is located within the Middle-Lower Yangtze River Metallogenic Belt (MLYRMB) of central-eastern China. However, this area contains thick and widespread unprospective sedimentary cover sequences that have impeded traditional approaches to mineral exploration. This study presents the results of 3D numerical simulation modeling that identifies possible mineral exploration targets within the entire Xuancheng-Magushan orefield. This modeling enables the identification of unexplored areas with significant exploration potential that are covered by thick sedimentary sequences that cannot be easily …


Radiological Identification Of Near‐Surface Mineralogical Deposits Using Low‐Altitude Unmanned Aerial Vehicle, Peter G. Martin, Dean T. Connor, Natalia Estrada, Adel El-Turke, David Megson-Smith, Chris P. Jones, David K. Kreamer, Thomas B. Scott Oct 2020

Radiological Identification Of Near‐Surface Mineralogical Deposits Using Low‐Altitude Unmanned Aerial Vehicle, Peter G. Martin, Dean T. Connor, Natalia Estrada, Adel El-Turke, David Megson-Smith, Chris P. Jones, David K. Kreamer, Thomas B. Scott

Geoscience Faculty Publications

An ever‐increasing global population and unabating technological growth have resulted in a relentless appetite for mineral resources, namely rare earth elements, fuel minerals and those utilised in electronics applications, with the price of such species continuing to climb. In contrast to more established large‐scale and high‐cost exploration methodologies, this work details the application of novel multi‐rotor unmanned aerial vehicles equipped with miniaturised radiation detectors for the objective of undertaking resource exploration at lower costs, with greater autonomy and at considerably enhanced higher spatial resolutions; utilizing the ore material’s inherent low levels of characteristic radioactivity. As we demonstrate at the former …


Future Availability Of Non-Renewable Metal Resources And The Influence Of Environmental, Social, And Governance Conflicts On Metal Production, Simon Jowitt, Gavin M. Mudd, John F.H. Thompson Sep 2020

Future Availability Of Non-Renewable Metal Resources And The Influence Of Environmental, Social, And Governance Conflicts On Metal Production, Simon Jowitt, Gavin M. Mudd, John F.H. Thompson

Geoscience Faculty Publications

Metal mining provides the elements required for the provision of energy, communication, transport and more. The increasing uptake of green technology, such as electric vehicles and renewable energy, will also further increase metal demand. However, the production lifespan of an average mine is far shorter than the timescales of mineral deposit formation, suggesting that metal mining is unsustainable on human timescales. In addition, some research suggests that known primary metal supplies will be exhausted within about 50 years. Here we present an analysis of global metal reserves that suggests that primary metal supplies will not run out on this timescale. …


Great Basin Paleoclimate And Aridity Linked To Artic Warming And Tropical Pacific Sea Surface Temperature, Matthew S. Lachniet, Yemane Asmerom, Victor Polyak, Rhawn Denniston Jun 2020

Great Basin Paleoclimate And Aridity Linked To Artic Warming And Tropical Pacific Sea Surface Temperature, Matthew S. Lachniet, Yemane Asmerom, Victor Polyak, Rhawn Denniston

Geoscience Faculty Publications

The arid southwestern United States is susceptible to sustained droughts that impact water resources and economic activity for millions of residents. Previous work has not systematically investigated the structure, timing, and possible forcings of Holocene Great Basin sub‐orbital hydroclimate changes, impeding our ability to understand the potential future controls on Southwestern aridity. The objective of this paper is to constrain the potential forcings on Holocene aridity and temperature, via comparison of new high‐resolution speleothem data, an Aridity Index synthesizing hydroclimate records, and linkages of Southwestern paleoclimate to other regions. The high‐resolution data from Leviathan Cave provide a paleoclimate record since …


Pacific Southwest United States Holocene Droughts And Pluvials Inferred From Sediment Δ18o (Calcite) And Grain Size Data (Lake Elsinore, California), Matthew E.C. Kirby, William Paul Patterson, Matthew Lachniet, James A. Noblet, Michael A. Anderson, Kevin Nichols, Judith Avila Apr 2019

Pacific Southwest United States Holocene Droughts And Pluvials Inferred From Sediment Δ18o (Calcite) And Grain Size Data (Lake Elsinore, California), Matthew E.C. Kirby, William Paul Patterson, Matthew Lachniet, James A. Noblet, Michael A. Anderson, Kevin Nichols, Judith Avila

Geoscience Faculty Publications

Records of past climate can inform us on the natural range and mechanisms of climate change. In the arid Pacific southwestern United States (PSW), which includes southern California, there exist a variety of Holocene records that can be used to infer past winter conditions (moisture and/or temperature). Holocene records of summer climate, however, are rare from the PSW. In the future, climate changes due to anthropogenic forcing are expected to increase the severity of drought in the already water stressed PSW. Hot droughts are of considerable concern as summer temperatures rise. As a result, understanding how summer conditions changed in …


Speleothem Paleoclimatology For The Caribbean, Central America, And North America, Jessica L. Oster, Sophie F. Warken, Natasha Sekhon, Monica M. Arienzo, Matthew Lachniet Jan 2019

Speleothem Paleoclimatology For The Caribbean, Central America, And North America, Jessica L. Oster, Sophie F. Warken, Natasha Sekhon, Monica M. Arienzo, Matthew Lachniet

Geoscience Faculty Publications

Speleothem oxygen isotope records from the Caribbean, Central, and North America reveal climatic controls that include orbital variation, deglacial forcing related to ocean circulation and ice sheet retreat, and the influence of local and remote sea surface temperature variations. Here, we review these records and the global climate teleconnections they suggest following the recent publication of the Speleothem Isotopes Synthesis and Analysis (SISAL) database. We find that low-latitude records generally reflect changes in precipitation, whereas higher latitude records are sensitive to temperature and moisture source variability. Tropical records suggest precipitation variability is forced by orbital precession and North Atlantic Ocean …


The Sisal Database: A Global Resource To Document Oxygen And Carbon Isotope Records From Speleothems, Kamolphat Atsawawaranunt, Laia Comas-Bru, Sahar Amirnezhad Mozhdehi, Michael Deininger, Sandy P. Harrison, Andy Baker, Meighan Boyd, Nikita Kaushal, Syed Masood Ahmad, Yassine Ait Brahim, Monica Arienzo, Petra Bajo, Kerstin Braun, Yuval Burstyn, Sakonvan Chawchai, Wuhui Duan, István Gábor Hatvani, Jun Hu, Zoltán Kern, Inga Labuhn, Matthew Lachniet, Franziska A. Lechleitner, Andrew Lorrey, Carlos Pérez-Mejías, Robyn Pickering, Nick Scroxton, Sisal Working Group Members Sep 2018

The Sisal Database: A Global Resource To Document Oxygen And Carbon Isotope Records From Speleothems, Kamolphat Atsawawaranunt, Laia Comas-Bru, Sahar Amirnezhad Mozhdehi, Michael Deininger, Sandy P. Harrison, Andy Baker, Meighan Boyd, Nikita Kaushal, Syed Masood Ahmad, Yassine Ait Brahim, Monica Arienzo, Petra Bajo, Kerstin Braun, Yuval Burstyn, Sakonvan Chawchai, Wuhui Duan, István Gábor Hatvani, Jun Hu, Zoltán Kern, Inga Labuhn, Matthew Lachniet, Franziska A. Lechleitner, Andrew Lorrey, Carlos Pérez-Mejías, Robyn Pickering, Nick Scroxton, Sisal Working Group Members

Geoscience Faculty Publications

Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide out-of-sample evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (δ18O, δ13C) measurements are …


Formation Of Evolved Rocks At Gale Crater By Crystal Fractionation And Implications For Mars Crustal Composition, Arya Udry, Esteban Gazel, Harry Y. Mcsween Jr. May 2018

Formation Of Evolved Rocks At Gale Crater By Crystal Fractionation And Implications For Mars Crustal Composition, Arya Udry, Esteban Gazel, Harry Y. Mcsween Jr.

Geoscience Faculty Publications

The recent discovery of some ancient evolved rocks in Gale crater by the Curiosity rover has prompted the hypothesis that continental crust formed in early Martian history. Here we present petrological modeling that attempts to explain this lithological diversity by magma fractionation. Using the thermodynamical software MELTS, we model fractional crystallization of different Martian starting compositions that might generate felsic igneous compositions like those analyzed at Gale crater using different variables, such as pressure, oxygen fugacities, and water content. We show that similar chemical and mineralogical compositions observed in Gale crater felsic rocks can readily be obtained through different degrees …


Introduction To A Resources Special Issue On Criticality Of The Rare Earth Elements: Current And Future Sources And Recycling, Simon M. Jowitt May 2018

Introduction To A Resources Special Issue On Criticality Of The Rare Earth Elements: Current And Future Sources And Recycling, Simon M. Jowitt

Geoscience Faculty Publications

The rare earth elements (REE) are vital to modern technologies and society and are amongst the most important of the critical elements. This special issue of Resources examines a number of facets of these critical elements, current and future sources of the REE, the mineralogy of the REE, and the economics of the REE sector. These papers not only provide insights into a wide variety of aspects of the REE, but also highlight the number of different areas of research that need to be undertaken to ensure sustainable and secure supplies of these critical metals into the future.


Provenance And Paleogeography Of The 25-17 Ma Rainbow Gardens Formation: Evidence For Tectonic Activity At Ca. 19 Ma And Internal Drainage Rather Than Throughgoing Paleorivers On The Southwestern Colorado Plateau, Melissa A. Lamb, L. Sue Beard, Malia Dragos, Andrew D. Hanson, Thomas A. Hickson, Mark Sitton, Paul J. Umhoefer, Karl E. Karlstrom, Nelia Dunbar, William Mcintosh May 2018

Provenance And Paleogeography Of The 25-17 Ma Rainbow Gardens Formation: Evidence For Tectonic Activity At Ca. 19 Ma And Internal Drainage Rather Than Throughgoing Paleorivers On The Southwestern Colorado Plateau, Melissa A. Lamb, L. Sue Beard, Malia Dragos, Andrew D. Hanson, Thomas A. Hickson, Mark Sitton, Paul J. Umhoefer, Karl E. Karlstrom, Nelia Dunbar, William Mcintosh

Geoscience Faculty Publications

The paleogeographic evolution of the Lake Mead region of southern Nevada and northwest Arizona is crucial to understanding the geologic history of the U.S. Southwest, including the evolution of the Colorado Plateau and formation of the Grand Canyon. The ca. 25–17 Ma Rainbow Gardens Formation in the Lake Mead region, the informally named, roughly coeval Jean Conglomerate, and the ca. 24–19 Ma Buck and Doe Conglomerate southeast of Lake Mead hold the only stratigraphic evidence for the Cenozoic pre-extensional geology and paleogeography of this area. Building on prior work, we present new sedimentologic and stratigraphic data, including sandstone provenance and …


Craters Of The Moon National Monument Basalts As Unshocked Compositional And Weathering Analogs For Martian Rocks And Meteorites, Christopher T. Adcock, Arya Udry, Elisabeth M. Hausrath, Oliver Tschauner Apr 2018

Craters Of The Moon National Monument Basalts As Unshocked Compositional And Weathering Analogs For Martian Rocks And Meteorites, Christopher T. Adcock, Arya Udry, Elisabeth M. Hausrath, Oliver Tschauner

Geoscience Faculty Publications

The availability of terrestrial sites that are martian analogs allows researchers to investigate Mars using knowledge gained on Earth. Among the terrestrial analog sites for Mars is Craters of the Moon National Monument (COTM) in Idaho, U.S.A. Craters of the Moon National Monument is home to over 60 basalt lava flows, many of which have been dated from 2050 to 18 340 years before present (y.b.p.). Following previous authors, we examined the chemistry and petrogenesis of COTM basalts compared to basaltic martian rocks, martian meteorites, and meteorite clasts, and then examined the results of chemical weathering of the basaltic flows. …


Humans Thrived In South Africa Through The Toba Eruption About 74,000 Years Ago, Eugene I. Smith, Zenobia Jacobs, Racheal Johnsen, Minghua Ren, Erich C. Fisher, Simen Oestmo, Jayne Wilkins, Jacob A. Harris, Panagiotis Karkanas, Shelby Fitch, Amber Ciravolo, Deborah Keenan, Naomi Cleghorn, Christine S. Lane, Thalassa Matthews, Curtis W. Marean Mar 2018

Humans Thrived In South Africa Through The Toba Eruption About 74,000 Years Ago, Eugene I. Smith, Zenobia Jacobs, Racheal Johnsen, Minghua Ren, Erich C. Fisher, Simen Oestmo, Jayne Wilkins, Jacob A. Harris, Panagiotis Karkanas, Shelby Fitch, Amber Ciravolo, Deborah Keenan, Naomi Cleghorn, Christine S. Lane, Thalassa Matthews, Curtis W. Marean

Geoscience Faculty Publications

Approximately 74 thousand years ago (ka), the Toba caldera erupted in Sumatra. Since the magnitude of this eruption was first established, its effects on climate, environment and humans have been debated1. Here we describe the discovery of microscopic glass shards characteristic of the Youngest Toba Tuff—ashfall from the Toba eruption—in two archaeological sites on the south coast of South Africa, a region in which there is evidence for early human behavioural complexity. An independently derived dating model supports a date of approximately 74 ka for the sediments containing the Youngest Toba Tuff glass shards. By defining the input of shards …


Elastic Geothermobarometry: Corrections For The Geometry Of The Host-Inclusion System, M. L. Mazzucchelli, Pamela Burnley, R. J. Angel, S. Morganti, M. C. Domeneghetti, F. Nestola, M. Alvaro Jan 2018

Elastic Geothermobarometry: Corrections For The Geometry Of The Host-Inclusion System, M. L. Mazzucchelli, Pamela Burnley, R. J. Angel, S. Morganti, M. C. Domeneghetti, F. Nestola, M. Alvaro

Geoscience Faculty Publications

Elastic geothermobarometry on inclusions is a method to determine pressure-temperature conditions of mineral growth independent of chemical equilibrium. Because of the difference in their elastic properties, an inclusion completely entrapped inside a host mineral will develop a residual stress upon exhumation, from which one can back-calculate the entrapment pressure. Current elastic geobarometric models assume that both host and inclusion are elastically isotropic and have an ideal geometry (the inclusion is spherical and isolated at the center of an infinite host). These conditions do not commonly occur in natural rocks, and the consequences for inclusion pressures can only be quantified with …


Nevada Desert Dust With Heavy Metals Suppresses Igm Antibody Production, Deborah E. Keil, Brenda J. Buck, Dirk Goossens, Brett Mclaurin, Lacey Murphy, Mallory Leetham-Spencer, Yuanxin Teng, James E. Pollard, Russell Gerads, Jamie C. Dewitt Jan 2018

Nevada Desert Dust With Heavy Metals Suppresses Igm Antibody Production, Deborah E. Keil, Brenda J. Buck, Dirk Goossens, Brett Mclaurin, Lacey Murphy, Mallory Leetham-Spencer, Yuanxin Teng, James E. Pollard, Russell Gerads, Jamie C. Dewitt

Geoscience Faculty Publications

Systemic health effects from exposure to a complex natural dust containing heavy metals from the Nellis Dunes Recreation Area (NDRA) near Las Vegas, NV, were evaluated. Several toxicological parameters were examined following lung exposure to emissive dust from three geologic sediment types heavily used for recreational off-road activities: yellow sand very rich in arsenic (termed CBN 5); a shallow cover of loose dune sand overlying a gravelly subsoil bordering dune fields (termed CBN 6); and brown claystone and siltstone (termed CBN 7). Adult female B6C3F1 mice were exposed by oropharyngeal administration to these three types of geogenic dusts at 0.01–100 …


U–Pb Dating Of Cave Spar: A New Shallow Crust Landscape Evolution Tool, D. D. Decker, V. J. Ployak, Y. Asmeron, Matthew Lachniet Nov 2017

U–Pb Dating Of Cave Spar: A New Shallow Crust Landscape Evolution Tool, D. D. Decker, V. J. Ployak, Y. Asmeron, Matthew Lachniet

Geoscience Faculty Publications

In carbonate terranes, rocks types that provide apatite are not available to effectively use apatite fission track (AFT) or (U/Th)‐He chronometry (AHe). Here we suggest that calcite cave spar can be an effective chronometer and complimentary to AFT and AHe thermochronometers in carbonate regions such as our study area, the Guadalupe Mountains of southeastern New Mexico, and west Texas. Our measured depth of cave spar deposition is 500 ± 250 m beneath the regional water table, formed at temperatures of 40° to 80°C, indicating that these caves and their spar crystals form near the supercritical CO2‐subcritical CO2 boundary where we …