Now showing items 1-20 of 117

    • The earliest equatorial record of frogs from the Late Triassic of Arizona 

      Stocker, Michelle R.; Nesbitt, Sterling J.; Kligman, Ben T.; Paluh, Daniel J.; Marsh, Adam D.; Blackburn, David C.; Parker, William G. (Royal Society Publishing, 2019-02-01)
      Crown-group frogs (Anura) originated over 200 Ma according to molecular phylogenetic analyses, though only a few fossils from high latitudes chronicle the first approximately 60 Myr of frog evolution and distribution. We ...
    • The TECHtonic, Fall 2018 

      Unknown author (Virginia Tech, 2018)
      This is the newsletter for the Department of Geosciences, published twice annually.
    • Transient marine euxinia at the end of the terminal Cryogenian glaciation 

      Lang, Xianguo; Shen, Bing; Peng, Yongbo; Xiao, Shuhai; Zhou, Chuanming; Bao, Huiming; Kaufman, Alan Jay; Huang, Kangjun; Crockford, Peter W.; Liu, Yonggang; Tang, Wenbo; Ma, Haoran (Springer Nature, 2018-08-01)
      Termination of the terminal Cryogenian Marinoan snowball Earth glaciation (similar to 650-635 Ma) is associated with the worldwide deposition of a cap carbonate. Modeling studies suggest that, during and immediately following ...
    • Extensive marine anoxia during the terminal Ediacaran Period 

      Zhang, Feifei; Xiao, Shuhai; Kendall, Brian; Romaniello, Stephen J.; Cui, Huan; Meyer, Mike; Gilleaudeau, Geoffrey J.; Kaufman, Alan J.; Anbar, Ariel D. (AAAS, 2018-06-20)
      The terminal Ediacaran Period witnessed the decline of the Ediacara biota (which may have included many stem-group animals). To test whether oceanic anoxia might have played a role in this evolutionary event, we measured ...
    • Investigating the Sulphur Cycle during the End-Triassic Mass Extinction from Panthalassa 

      Marroquín, Selva; Gill, Benjamin; Them, Theodore R.; Owens, Jeremy D.; Gröcke, Darren R.; Caruthers, Andrew H. (2018-08-15)
      The end-Triassic mass extinction (~201 Ma), one of the “Big Five” mass extinctions of the Phanerozoic,is estimated to have resulted in the loss of ~80%of known marine species. This interval is also ...
    • Tracking Marine Deoxygenation during the Cambrian SPICE Event Using Thallium Isotopes 

      LeRoy, Mathew; Gill, Benjamin; Them, Theodore R.; Owens, Jeremy D. (2018-08-15)
      The stable isotopic composition of thallium (ε205Tl) in organic-rich, sulfidic sediments has recently emerged as a new proxy for tracking changes in global marine redox conditions in the geologic ...
    • Toarcian Mercury Anomalies Record Terrestrial Disturbance Rather Than Volcanic Activity 

      Them, Theodore R.; Jagoe, C. H.; Gill, Benjamin; Caruthers, A. H.; Grasby, S. E.; Gröcke, D. R.; Yin, R.; Owens, J. D. (2018-08-15)
      Mercury (Hg) enrichments in ancient sedimentary successions are currently used to directly link the emplacement of large igneous provinces (LIPs) to environmental change and biological turnover in the geological record. ...
    • Environmental Divers of Decoupled Marine Sulfate Oxygen and Sulfur Isotope Trends during the Toarcian Oceanic Anoxic Event 

      Gomes, Maya; Waldek, Anna; Gill, Benjamin; Johnston, David (2019-08-12)
      The Toarcian Oceanic Anoxic Event was a major carbon cycle perturbation associated with two pulses of extinction and widespread environmental change. Studies of the biogeochemical sulfur cycle provide insight into the ...
    • Early crocodylomorph increases top tier predator diversity during rise of dinosaurs 

      Zanno, Lindsay E.; Drymala, Susan; Nesbitt, Sterling J.; Schneider, Vincent P. (Springer Nature, 2015-03-19)
      Triassic predatory guild evolution reflects a period of ecological flux spurred by the catastrophic end-Permian mass extinction and terminating with the global ecological dominance of dinosaurs in the early Jurassic. In ...
    • Taphonomy And Biological Affinity Of Three-Dimensionally Phosphatized Bromalites From The Middle Ordovician Winneshiek Lagerstätte, Northeastern Iowa, USA 

      Hawkins, Andrew D.; Liu, Huaibao P.; Briggs, Derek E. G.; Muscente, A. D.; McKay, Robert M.; Witzke, Brian J.; Xiao, Shuhai (2018-01-09)
      The Winneshiek Lagerst¨atte occurs within an Ordovician meteorite impact structure beneath part of the city of Decorah, Iowa. The Lagerst¨atte has yielded an atypical marine fauna including phyllocarid crustaceans, ...
    • The competing effects of microbially derived polymeric and low molecular-weight substances on the dispersibility of CeO2 nanoparticles 

      Nakano, Yuriko; Ochiai, Asumi; Kawamoto, Keisuke; Takeda, Ayaka; Ichiyoshi, Kenta; Ohnuki, Toshihiko; Hochella, Michael F. Jr.; Utsunomiya, Satoshi (Springer Nature, 2018-02-26)
      To understand the competing effects of the components in extracellular substances (ES), polymeric substances (PS) and low-molecular-weight small substances (SS) <1 kDa derived from microorganisms, on the colloidal stability ...
    • The 2015 landslide and tsunami in Taan Fiord, Alaska 

      Higman, Bretwood; Shugar, Dan H.; Stark, Colin P.; Ekstrom, Goran; Koppes, Michele N.; Lynett, Patrick; Dufresne, Anja; Haeussler, Peter J.; Geertsema, Marten; Gulick, Sean; Mattox, Andrew; Venditti, Jeremy G.; Walton, Maureen A. L.; McCall, Naoma; Mckittrick, Erin; MacInnes, Breanyn; Bilderback, Eric L.; Tang, Hui; Willis, Michael J.; Richmond, Bruce; Reece, Robert S.; Larsen, Chris; Olson, Bjorn; Capra, James; Ayca, Aykut; Bloom, Colin; Williams, Haley; Bonno, Doug; Weiss, Robert; Keen, Adam; Skanavis, Vassilios; Loso, Michael (Springer Nature, 2018-09-06)
      Glacial retreat in recent decades has exposed unstable slopes and allowed deep water to extend beneath some of those slopes. Slope failure at the terminus of Tyndall Glacier on 17 October 2015 sent 180 million tons of rock ...
    • Sulphur and carbon cycling in the subduction zone melange 

      Schwarzenbach, Esther M.; Caddick, Mark J.; Petroff, Matthew; Gill, Benjamin C.; Cooperdock, Emily H. G.; Barnes, Jaime D. (Springer Nature, 2018-10-19)
      Subduction zones impose an important control on the geochemical cycling between the surficial and internal reservoirs of the Earth. Sulphur and carbon are transferred into Earth's mantle by subduction of pelagic sediments ...
    • Drilling Predation on Serpulid Polychaetes (Ditrupa arietina) from the Pliocene of the Cope Basin, Murcia Region, Southeastern Spain 

      Martinell, Jordi; Kowalewski, Michal; Domenech, Rosa (PLOS, 2012-04-05)
      We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the ...
    • Low Concentrations of Silver Nanoparticles in Biosolids Cause Adverse Ecosystem Responses under Realistic Field Scenario 

      Colman, Benjamin P.; Arnaout, Christina L.; Anciaux, Sarah; Gunsch, Claudia K.; Hochella, Michael F. Jr.; Kim, Bojeong; Lowry, Gregory V.; McGill, Bonnie M.; Reinsch, Brian C.; Richardson, Curtis J.; Unrine, Jason M.; Wright, Justin P.; Yin, Liyan; Bernhardt, Emily S. (PLOS, 2013-02-27)
      A large fraction of engineered nanomaterials in consumer and commercial products will reach natural ecosystems. To date, research on the biological impacts of environmental nanomaterial exposures has largely focused on ...
    • Discovery and ramifications of incidental Magnéli phase generation and release from industrial coal-burning 

      Yang, Yi; Chen, Bo; Hower, James C.; Schindler, Michael; Winkler, Christopher; Brandt, Jessica E.; Di Giulio, Richard T.; Ge, Jianping; Liu, Min; Fu, Yuhao; Zhang, Lijun; Chen, Yu-ru; Priya, Shashank; Hochella, Michael F. Jr. (Nature Publishing Group, 2017-01-12)
      Coal, as one of the most economic and abundant energy sources, remains the leading fuel for producing electricity worldwide. Yet, burning coal produces more global warming CO2 relative to all other fossil fuels, and it is ...
    • The TECHtonic, Spring 2018 

      Unknown author (Virginia Tech, 2018)
      This is the newsletter for the Department of Geosciences, published twice annually.
    • A modest 0.5-m rise in sea level will double the tsunami hazard in Macau 

      Li, Linlin; Switzer, Adam D.; Wang, Yu; Chan, Chung-Han; Qiu, Qiang; Weiss, Robert (AAAS, 2018-08-15)
      Rising sea levels will have overwhelmingly negative impacts on coastal communities globally. With previous research focused on how sea-level rise (SLR) affects storm-induced flooding, we show that SLR will also increase ...
    • Late Ediacaran trackways produced by bilaterian animals with paired appendages 

      Chen, Zhe; Chen, Xiang; Zhou, Chuanming; Yuan, Xunlai; Xiao, Shuhai (AAAS, 2018-06-06)
      Ediacaran trace fossils provide key paleontological evidence for the evolution of early animals and their behaviors. Thus far, however, this fossil record has been limited to simple surface trails and relatively shallow ...
    • A Geodetic Strain Rate Model for the East African Rift System 

      Stamps, D.S.; Saria, E.; Kreemer, C. (Nature, 2018-01-15)
      Here we describe the new Sub-Saharan Africa Geodetic Strain Rate Model v.1.0 (SSA-GSRM v.1.0), which provides fundamental constraints on long-term tectonic deformation in the region and an improved seismic hazards assessment ...