Recent Submissions

  • Crustal Anisotropy Beneath the Trans-North China Orogen and its Adjacent Areas From Receiver Functions 

    Xu, Xiaoming; Ding, Zhifeng; Li, Li; Niu, Fenglin (2021)
    As an important segment of the North China Craton, the Trans-North China Orogen (TNCO) has experienced strong tectonic deformation and magmatic activities since the Cenozoic and is characterized by significant seismicity. To understand the mechanism of the crustal deformation and seismic hazards, we determined the crustal thickness (H), Vp/Vs ratio ...
  • Using computer-aided image processing to estimate chemical composition of igneous rocks: A potential tool for large-scale compositional mapping 

    Zhang, Julin; Lee, Cin-Ty A.; Farner, Michael (2021)
    Digital cameras, particularly on smartphones, have led to the proliferation of amateur photographers. Of interest here is the use of smartphone cameras to conduct rapid, low-cost compositional mapping of geologic bedrock, such as plutons and batholiths, in combination with chemical analyses of rocks in the laboratory. This paper discusses some of the ...
  • Origin of the J-M Reef and Lower Banded series, Stillwater Complex, Montana, USA 

    Jenkins, M. Christopher; Mungall, James E.; Zientek, Michael L.; Costin, Gelu; Yao, Zhuo-sen (2021)
    The origin and parental magma for layered cumulates in the Lower Banded series (LBS) and the J-M Reef Pd-Pt deposit of the Stillwater Complex remains poorly constrained. We present whole-rock lithogeochemistry and mineral chemistry from LBS rocks collected from drill holes and surface samples from the Mountain View area of the complex that in total ...
  • Pore and Mineral Fabrics Control the Elastic Wave Velocities of Metapelite With Implications for Subduction Zone Tomography 

    Fliedner, C.; French, M. E. (2021)
    Seismic tomography is used to infer compositional variations and environmental conditions in active subduction zones. In some regions, low P-wave and S-wave velocities and high are documented near and along the plate boundary, and are interpreted to reflect high pore fluid pressures in metasedimentary rocks. However, there are limited experimental ...
  • Topographic Controls on Channelized Meltwater in the Subglacial Environment 

    Simkins, L. M.; Greenwood, S. L.; Munevar Garcia, S.; Eareckson, E. A.; Anderson, J. B.; (2021)
    Realistic characterization of subglacial hydrology necessitates knowledge of the range in form, scale, and spatiotemporal evolution of drainage networks. A relict subglacial meltwater corridor on the deglaciated Antarctic continental shelf encompasses 80 convergent and divergent channels, many of which are hundreds of meters wide and several of which ...
  • Continuous plate subduction marked by the rise of alkali magmatism 2.1 billion years ago 

    Liu, He; Sun, Wei-dong; Zartman, Robert; Tang, Ming (2019)
    Over the Earth’s evolutionary history, the style of plate subduction has evolved through time due to the secular cooling of the mantle. While continuous subduction is a typical feature of modern plate tectonics, a stagnant-lid tectonic regime with localized episodic subduction likely characterized the early Earth. The timing of the transition between ...
  • A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay 

    Schroeder, Dustin M.; MacKie, Emma J.; Creyts, Timothy T.; Anderson, John B. (2019)
    Late Holocene sediment deposits in Pine Island Bay, West Antarctica, are hypothesized to be linked to intensive meltwater drainage during the retreat of the paleo-Pine Island Ice Stream after the Last Glacial Maximum. The uppermost sediment units show an abrupt transition from ice-proximal debris to a draped silt during the late Holocene, which is ...
  • Timescale dependent sedimentary record during the past 130 kyr from a tropical mixed siliciclastic–carbonate shelf edge and slope: Ashmore Trough (southern Gulf of Papua) 

    Mallarino, Gianni; Francis, Jason M.; Jorry, Stephan J.; Daniell, James J.; Droxler, AndrÉ W.; (2021)
    In tropical and sub-tropical mixed siliciclastic–carbonate depositional systems, fluvial input and in situ neritic carbonate interact over space and time. Despite being the subject of many studies, controls on partitioning of mixed sediments remains controversial. Mixed sedimentary records, from Ashmore Trough shelf edge and slopes (southern Gulf of ...
  • The trajectory of soil development and its relationship to soil carbon dynamics 

    Lawrence, Corey R.; Schulz, Marjorie S.; Masiello, Caroline A.; Chadwick, Oliver A.; Harden, Jennifer W. (2021)
    It has been postulated that the amount of soil organic carbon (SOC) associated with soil minerals exhibits a threshold relationship in response to effective soil moisture (estimated as precipitation less evapotranspiration). To better characterize the role of moisture in influencing mechanisms of SOC storage during pedogenesis, we compare soils from ...
  • Impacts of Engineered Diversions and Natural Avulsions on Delta-Lobe Stability 

    Carlson, Brandee N.; Nittrouer, Jeffrey A.; Swanson, Travis E.; Moodie, Andrew J.; Dong, Tian Y.; (2021)
    Reduced sediment supply and rising sea levels are driving land submergence on deltas worldwide, motivating engineering practices that divert water and sediment to sustain coastal landforms. However, lobe response following channel abandonment by diversions has not been constrained by field-scale studies. Herein, avulsion and engineered diversion ...
  • Oxygen isotope exchange rates between phosphate and water catalyzed by inorganic pyrophosphatase: Implications for the biogeochemical cycle of phosphorus 

    Chang, Sae Jung; Blake, Ruth E.; Colman, Albert S. (2021)
    The oxygen isotope composition of phosphate (δ18OPO4) has been widely used as (paleo)temperature and bio-signature proxies and a tracer of biogeochemical cycling of phosphorus (P). In natural aqueous systems, reactive inorganic phosphorus is dominantly present as dissolved inorganic phosphate (DIP), and reactions involving DIP are primarily carried ...
  • Local events-based fast RTM surface-offset gathers via dip-guided interpolation 

    Zhao, Yang; Niu, Feng-Lin; Fu, Lei; Cheng, Cheng; Chen, Jin-Hong; (2021)
    Reverse Time Migration (RTM) Surface Offset Gathers (SOGs) are demonstrated to deliver more superior residual dip information than ray-based approaches. It appears more powerful in complex geological settings, such as salt areas. Still, the computational cost of constructing RTM SOGs is a big challenge in applying it to 3D field data. To tackle this ...
  • Adjoint traveltime tomography unravels a scenario of horizontal mantle flow beneath the North China craton 

    Dong, Xingpeng; Yang, Dinghui; Niu, Fenglin; Liu, Shaolin; Tong, Ping (2021)
    The North China craton (NCC) was dominated by tectonic extension from late Cretaceous to Cenozoic, yet seismic studies on the relationship between crust extension and lithospheric mantle deformation are scarce. Here we present a three dimensional radially anisotropic model of NCC derived from adjoint traveltime tomography to address this issue. We ...
  • Optimized river diversion scenarios promote sustainability of urbanized deltas 

    Moodie, Andrew J.; Nittrouer, Jeffrey A. (2021)
    Socioeconomic viability of fluvial-deltaic systems is limited by natural processes of these dynamic landforms. An especially impactful occurrence is avulsion, whereby channels unpredictably shift course. We construct a numerical model to simulate artificial diversions, which are engineered to prevent channel avulsion, and direct sediment-laden water ...
  • Rapid endogenic rock recycling in magmatic arcs 

    Li, Jun-Yong; Tang, Ming; Lee, Cin-Ty A.; Wang, Xiao-Lei; Gu, Zhi-Dong; (2021)
    In subduction zones, materials on Earth’s surface can be transported to the deep crust or mantle, but the exact mechanisms and the nature of the recycled materials are not fully understood. Here, we report a set of migmatites from western Yangtze Block, China. These migmatites have similar bulk compositions as forearc sediments. Zircon age distributions ...
  • Reciprocity-gap misfit functional for distributed acoustic sensing, combining data from passive and active sources 

    Faucher, Florian; de Hoop, Maarten V.; Scherzer, Otmar (2021)
    Quantitative imaging of subsurface earth properties in elastic media is performed from distributed acoustic sensing data. A new misfit functional based upon the reciprocity gap is designed, taking crosscorrelations of displacement and strain, and these products further associate an observation with a simulation. In comparison with other misfit ...
  • Phosphorus Release and Regeneration Following Laboratory Lysis of Bacterial Cells 

    Mine, Aric H.; Coleman, Maureen L.; Colman, Albert S. (2021)
    The availability of phosphorus limits primary production in large regions of the oceans, and marine microbes use a variety of strategies to overcome this limitation. One strategy is the production of alkaline phosphatase (APase), which allows hydrolysis of larger dissolved organic phosphorus (DOP) compounds in the periplasm or at the cell surface for ...
  • Aquifer Monitoring Using Ambient Seismic Noise Recorded With Distributed Acoustic Sensing (DAS) Deployed on Dark Fiber 

    Tribaldos, Verónica Rodríguez; Ajo-Franklin, Jonathan B. (2021)
    Groundwater is a critical resource for human activities worldwide, and a vital component of many natural ecosystems. However, the state and dynamics of water-bearing aquifers remain uncertain, mostly due to the paucity of subsurface data at high spatial and temporal resolution. Here, we show that analysis of infrastructure-generated ambient seismic ...
  • Utilizing distributed acoustic sensing and ocean bottom fiber optic cables for submarine structural characterization 

    Cheng, Feng; Chi, Benxin; Lindsey, Nathaniel J.; Dawe, T. Craig; Ajo-Franklin, Jonathan B. (2021)
    The sparsity of permanent seismic instrumentation in marine environments often limits the availability of subsea information on geohazards, including active fault systems, in both time and space. One sensing resource that provides observational access to the seafloor environment are existing networks of ocean bottom fiber optic cables; these cables, ...
  • Constraining maximum event magnitude during injection-triggered seismicity 

    Li, Ziyan; Elsworth, Derek; Wang, Chaoyi; EGS-Collab (2021)
    Understanding mechanisms controlling fluid injection-triggered seismicity is key in defining strategies to ameliorate it. Recent triggered events (e.g. Pohang, Mw 5.5) have exceeded predictions of average energy release by a factor of >1000x, necessitating robust methodologies to both define critical antecedent conditions and to thereby constrain ...

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