Department Of Earth Research Articles

Graduate studies in underwater acoustics at the University of Washington

The University of Washington through its Departments of Mechanical and Electrical Engineering (College of Engineering), Department of Earth and Space Sciences, and School of Oceanography (College of the Environment), and by way of its Applied Physics Laboratory, which links all four of these academic units, offers a diverse graduate education experience in underwater acoustics. A summary is provided of the research infrastructure, primarily made available through Applied Physics Laboratory, which allows for ocean going and arctic field opportunities, and course options offered through the four units that provide the multi-disciplinary background essential for graduate training in the field of underwater acoustics. Students in underwater acoustics can also mingle in or extend their interests into medical acoustics research. Degrees granted include both the M.S and Ph.D.

Underwater acoustics graduate study at the Applied Physics Laboratory, University of Washington

With faculty representation in the Departments of Electrical Engineering, and Mechanical Engineering within the College of Engineering, the School of Oceanography, and the Department of Earth and Space Sciences within the College of the Environment, underwater acoustics at APL-UW touches on topics as diverse as long range controlled source acoustics, very low frequency seismics, sediment acoustics, marine mammal vocalizations, and noise generated by industrial activities such as pile driving, among other things. Graduate studies leading to both M.S. and Ph.D. degrees are available. Examples of projects currently being pursued and student opportunities are highlighted in this poster.

The hydrogeological well database TANGRAM©: a tool for data processing to support groundwater assessment

At the Department of Earth and Environmental Sciences of the University of Milano-Bicocca (DISAT-UNIMIB), a hydrogeological well database, called TANGRAM©, has been developed and published on line at www.TANGRAM.samit.unimib.it, developing an earlier 1989 DOS version. This package can be used to store, display, and process all data related to water wells, including administrative information, well characteristics, stratigraphic logs, water levels, pumping rates, and other hydrogeological information. Currently, the database contains more than 39.200 wells located in the Italian region of Lombardy (90%), Piedmont (9%) and Valle d’Aosta (1%). TANGRAM© has been created both as a tool for researches and for public administration’s administrators who have projects in common with DISAT-UNIMIB. Indeed, transferring wells data from paper into TANGRAM© offers both an easier and more robust way to correlate hydrogeological data and a more organized management of the administrative information. Some Administrations use TANGRAM© regularly as a tool for wells data management (Brescia Province, ARPA Valle Aosta). An innovative aspect of the database is the quantitative extraction of stratigraphic data. In the part of the software intended for research purposes, all well logs are translated into 8-digit alphanumeric codes and the user composes the code interpreting the description at each stratigraphic level. So the stratigraphic well data can be coded, then quantified and processed. This is made possible by attributing a weight to the digits of the code for textures. The program calculates the weighted percentage of the chosen lithology, as related to each individual layer. These extractions are the starting point for subsequent hydrogeological studies: well head protection area, reconstruction of the dynamics of flow, realization of the quarry plans and flux and transport hydrogeological models. The results of a two-dimensional distribution of coarse, medium and fine sized material in the first 80 meters of depth are presented here for a study area located within the Province of Brescia (Italy).

Geodynamic significance of the boundary between the Thomson Orogen and the Lachlan Orogen, northwestern New South Wales and implications for Tasmanide tectonics: reply

Click to increase image sizeClick to decrease image sizeKEY WORDS: geodynamicsThomson OrogenLachlan Orogennorthwestern New South WalesTasmanide tectonicssouthern QueenslandView correction statement:Corrigendum ACKNOWLEDGEMENTSThe work on which the original paper and this reply were based was carried out by the Geological Survey of New South Wales, in cooperation with Geoscience Australia, the Predictive Mineral Discovery Cooperative Research Centre and GEMOC, the National Key Centre for the Geochemical Evolution and Metallogeny of Continents, in the Department of Earth and Planetary Sciences, Macquarie University, Sydney. Thanks to Ian Cooper (YTC Resources Limited) for discussions about Doradilla. Current and ex-staff of the Geological Survey of New South Wales publish with permission of the Director of the Geological Survey of New South Wales, NSW Trade & Investment. RJK publishes with permission of the Chief Executive Officer, Geoscience Australia.

Heterogeneous data management and modeling for the gravimetric geoid model: a review study in Pakistan

The gravimetric geoid model can be used as vertical reference in surveying and other related technologies. It is being developed by NESCOM in collaboration with the Department of Earth sciences QAU, Survey of Pakistan and Directorate General of Petroleum Concessions (DGPC). The data collection, selection, and analysis to make the data suitable for this purpose are being carried out. About 77,834 land gravity observations along with leveling and 11,787 Bouguer/free-air anomalies from GTECH are available and readily accessible. While GPS/leveling data for the whole Pakistan region is required and is being collected from different sources, though its density and quantity is not good enough for better calibration of gravimetric geoid. This study involves the feasibility and application of different datasets for the development of geoid model of Pakistan. The SRTM30 digital elevation model has been selected for topographic corrections and reductions due to its relatively better statistical comparison with local elevation data. Both least square collocation and FFT methods have been applied for this study. Two realistic studies have been carried out for global geopotential model selection based on statistical findings and evaluation of geoid-quasigeoid separation term in Pakistan. Geoid-quasigeoid separation term is an integral part of “Restore step” for geoid modeling with the utilization of the solution of the Molodensiky’s geodetic boundary value problem. The digital elevation model comparison with local leveling data shows that SRMT30 model is relatively better in accuracy (in terms of mean and standard deviation) than other counterparts such as Globe30, GTOPO30, and ETOPO2, etc. The results of geoid modeling have revealed that there exists a height bias of −70 cm between local vertical datum and global mean sea level.

Place-Based Geosciences Courses in a Diverse Urban College: Lessons Learned

ABSTRACT Recognizing the need to attract more students, especially those from underrepresented groups, a team of college faculty and experienced New York City Department of Education (DOE) Earth Science Teachers redesigned the two foundational Earth and Environmental Science courses required for all teacher and science major students in the Department of Earth and Environmental Sciences (EES). These two foundation courses have been taught in a survey style with broad, but shallow, content. The redesign team worked together to place greater emphasis on science process skills, technology, and discovery and chose air quality and beach morphodynamics as integrating topics for skill and content development throughout the courses. Students conducted long-term, place-based research within the city in ways that allowed them to apply the scientific method and develop skills necessary for practicing geoscientists, which included conducting online data searches, performing statistical analyses, graphing, using geographic information systems (GIS) and global positioning system (GPS), and making and giving presentations. Students used research-grade equipment, scanning electron microscopes (SEM), survey instruments, and petrology microscopes to collect and analyze their data. Iterative evaluations were conducted on the courses to provide guidance on ways to improve, and they formed the basis for course revisions in more-advanced courses.

Glaciology news in brief

Our “News in Brief” series, which examines the various areas and topics in the earth sciences, takes a look at recent emerging research in glaciology and focuses on its progress with the uncertainties in ice-mass change. Martin Sharp from Department of Earth and Atmospheric Sciences at the University of Alberta describes the efforts that have been undertaken in the glaciology community to produce “reconciled” estimates of the mass balance of the world’s land ice using a range of field-based and remote sensing techniques.

CORRIGENDUM

* The National Center for Atmospheric Research is sponsored by the National Science Foundation.Corresponding author address: Ming Cai, Department of Earth, Ocean, and Atmospheric Science, The Florida State University, 1017 Academic Way, Tallahassee, FL 32306. E-mail: mcai@fsu.edu

Stephen Guggenheim

The following introduction was made on behalf of the recipient at the 50th Anniversary Annual Meeting of The Clay Minerals Society held at the University of Illinois at Urbana-Champaign, on October 8, 2013, by: Ladies and gentlemen, it is a great honor to introduce Professor Stephen (Steve) Guggenheim from the Department of Earth and Environmental Sciences of the University of Illinois at Chicago for the 2013 Marilyn and Sturges W. Bailey Distinguished Member Award. Steve is internationally recognized as one of the leading crystallographers and mineralogists whose research has focused on the structure and crystal chemistry of layer silicates. Steve received his B.S. in Geology from Marietta College, Marietta, Ohio, in 1970 and his M.S. in Geology from the State University of New York at Stony Brook in 1972, where he worked on X-ray diffraction of heat-treated lunar pigeonites under the supervision of J.J. Papike. From there Steve went on to the University of Wisconsin-Madison to work on cation ordering in subgroup symmetry in the micas with Sturges ‘Bull’ Bailey for his Ph.D. His dissertation laid the foundation for an eminent career in clay mineralogy, which continues today. It is very fitting that …

A multi-disciplinary assessment of the southeastern United States climate

The southeastern United States (SUS) is a region that exhibits considerable climate variability throughout the year along with high-impact weather extremes of severe weather and land-falling Atlantic tropical cyclones in the summer and fall, freeze events in the winter season, and tornadoes in the spring season. The SUS region has rapidly grown in terms of human population for last several decades that further exposes vulnerabilities to the frailties of nature. Furthermore, in the recent times, the agricultural production of the region has grown significantly with the rise in consumption and demand for bio fuels, increase in price and demand for commodity and food crops and increasing irrigation infrastructure that is subsidized by the state governments in the SUS. Similarly, the coastal development and capitalization of natural marine resource environment have also risen with the growing wealth of the population. All of these developments have led to an increasing interest in the understanding of the climate variations and change on the built and the natural environments of the SUS. This special issue is a manifestation of such an interest in the SUS with contributions from several climate-related inter-disciplinary groups including the Southeast Climate Consortium (SECC; http://seclimate. org/), the Florida Climate Institute (FCI; http://floridacli mateinstitute.org/), the University of Florida Water Institute (http://waterinstitute.ufl.edu/), and the Florida Water & Climate Alliance (FloridaWCA; http://www.floridawca.org). There are 15 research papers in this special issue covering climate science and its applications in hydrology, ecology, economy, crop science, and social science. It is quite apparent from the diverse set of papers that the demand for ‘‘reliable’’ regional-scale climate data over the SUS is of considerable interest for climate impact assessment. As a result, there are several papers in this collection which dwell on developing the regional-scale climate information from dynamic downscaling (e.g., Misra et al. 2012), or from statistical downscaling (e.g., Asefa and Adams 2013) or from a combination of statistical and dynamical downscaling (e.g., Hwang et al. 2013). Asefa and Adams (2013) introduced in their paper a new statistical bias correction technique for regional climate projections over central Florida based on a Bayesian approach that weights on the reliability of the global climate model in reproducing the observed climate. Hwang et al. (2013) highlight the merit of using dynamically downscaled and statistically bias-corrected climate data for hydrological applications over the Tampa Bay watershed. Misra et al. (2012) show the advantage and fidelity of dynamically downscaling the twentieth-century global atmospheric reanalysis (20CR) to 10 km grid resolution. For example, they demonstrate that data inhomogeneity issues over SUS in the 20CR are greatly ameliorated by the internal variations resolved by the dynamic downscaling to 10-km grid resolution. The interest in regional-scale climate information over SUS is also evidenced in a number of papers in this special issue investigating the reliability of some of the existing high-resolution regional climate datasets. LaRow (2012) analyzes the surface wind and precipitation in land-falling Atlantic tropical cyclones over the SUS from one of the existing global reanalyses downscaled to 10 km grid resolution. Similarly, Obeysekera (2013) interrogates the reliability of the meteorological variables used in the calculation of the surface evapotranspiration from the V. Misra (&) Department of Earth, Ocean and Atmospheric Science & Florida Climate Institute & Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, USA e-mail: vmisra@fsu.edu

An Interview With Chapman Conference Chair Venkat Lakshmi

AGU's Chapman Conference program has been facilitating small collaborative meetings on topical and specialized subjects for more than 35 years. These meetings allow for debate and an exploration of possible solutions to scientific problems, while providing a professional networking opportunity for younger scientists. Venkat Lakshmi, professor of hydrology, climate, and water resources and former chair of the Department of Earth and Ocean Sciences at the University of South Carolina, was selected in January as the Chapman Conference program chair through 2015. Lakshmi, a former Eos editor, recalls with enthusiasm organizing a 2012 Chapman Conference in Hawaii: the proposal writing, the grant writing, soliciting presenters, and gathering scientific material. He is now using his experience organizing meetings and mentoring students at his university to help advance the Chapman program. Eos spoke with him about his new role and his vision for the program.

Honors

The U.S. National Academy of Sciences (NAS) recently announced its 2013 class of new members. They include Gregory Asner, faculty scientist in the Department of Global Ecology at the Carnegie Institution for Science, Stanford, Calif.; Mark Cane, G. Unger Vetlesen Professor of Earth and Climate Sciences in the Department of Earth and Environmental Sciences at the Lamont‐Doherty Earth Observatory of Columbia University, Palisades, N. Y.; Kenneth Farley, W. M. Keck Foundation Professor of Geochemistry and chair of the Division of Geological and Planetary Sciences, California Institute of Technology (Caltech), Pasadena; Terry Plank, professor in the Department of Earth and Environmental Sciences at Lamont‐Doherty; and John Seinfeld, Louis E. Nohl Professor in the Department of Chemical Engineering at Caltech.

Karenwebberite, Na(Fe2+,Mn2+)PO4, a new member of the triphylite group from the Malpensata pegmatite, Lecco Province, Italy

Karenwebberite, Na(Fe 2+ ,Mn 2+ )PO 4 , belongs to the triphylite group of minerals and corresponds to the Fe-equivalent of natrophilite or to the Na-equivalent of triphylite. It occurs in the Malpensata pegmatite dike, Colico, Lecco Province, Italy. Karenwebberite is found as late-magmatic-stage exsolution lamellae up to 100 μm thick, hosted by graftonite and associated with Na-bearing ferrisicklerite and with a heterosite-like phase. Lamellae are pale green, with very pale grayish-green streak. The luster is greasy to vitreous, and lamellae are translucent (pale green) to opaque (dark green). Optically, the mineral is anisotropic, biaxial (+), α = 1.701(2), β = 1.708(2), γ = 1.717(2) (for λ = 589 nm), 2 V meas = 87(4)°, 2 V calc = 41°, Z = b . Pleochroism is moderate with X = dark gray, Y = brown, and Z = yellow. The mineral is brittle with a Mohs hardness of 4.5; in thin section it displays a perfect cleavage along {001} with an irregular fracture. Karenwebberite is non-fluorescent either under short-wave or long-wave ultraviolet light, and its calculated density is 3.65 g/cm 3 . The mean chemical composition, determined by the electron microprobe from 16 point analyses (wt%), is: P 2 O 5 41.12, Fe 2 O 3 * 7.00, FeO* 25.82, MgO 0.23, ZnO 0.11, MnO 9.31, CaO 0.10, Na 2 O 14.66, total 98.41 (*: calculated values). The empirical formula, calculated on the basis of 1 P atom per formula unit from, is (Na 0.817 Ca 0.003 □ 0.180 ) ∑1.000 (Fe 2+ 0.622 Mn 2+ 0.228 Fe 3+ 0.151 Mg 0.010 Zn 0.002 ) ∑1.013 PO 4 . Karenwebberite is orthorhombic, space group Pbnm , a = 4.882(1), b = 10.387(2), c = 6.091(1) A, V = 308.9(1) A 3 , and Z = 4. The mineral possesses the olivine structure, with the M1 octahedra occupied by Na, and the M2 octahedra occupied by Fe and Mn. The eight strongest lines in the X-ray powder pattern are [ d in A (intensities) ( hkl )]: 5.16 (50) (020), 4.44 (90) (110), 3.93 (80) (021), 3.56 (90) (120), 3.04 (80) (002), 2.817 (100) (130), 2.559 (100) (131), and 1.657 (50) (061). The mineral is named in honor of Karen Louise Webber, Assistant Professor Research at the Mineralogy, Petrology and Pegmatology Research Group, Department of Earth and Environmental Sciences, University of New Orleans, Louisiana, U.S.A.

Late Glacial to early Holocene pollen stratigraphy of the SG06 core from Lake Suigetsu, Japan

a Department of Geography, University of Newcastle-upon-Tyne, UK. b Institute of Geological Sciences, Freie Universitat, Berlin, Germany. c Institute of Geography and Earth Sciences, University of Wales Aberystwyth, UK. d GeoForschungsZentrum, Potsdam, Germany. e Research Laboratory for Archaeology and the History of Art, University of Oxford, UK. f NERC Radiocarbon Facility (Environment), East Kilbride, UK. g Department of Biology and Geosciences, Osaka City University, Japan. h Faculty of Policy Informatics, Chiba University of Commerce, Japan. i Department of Earth and Planetary Sciences, University of Tokyo, Japan. j Ocean Research Institute, University of Tokyo, Japan. k College of Education, Naruto University of Education, Japan. l For full details see: www.suigetsu.org * Corresponding author: takeshi.nakagawa@newcastle.ac.uk

The Late Glacial in Japan: micro-facies analyses of the Lake Suigetsu sediments and palaeo-environmental implications

a GeoForschungsZentrum, Potsdam, Germany. b Institute of Geological Sciences, Freie Universitat, Berlin, Germany. c Institute of Geography and Earth Sciences, University of Wales Aberystwyth, UK. d Department of Geography, University of Newcastle-upon-Tyne, UK. e Department of Earth and Planetary Sciences, University of Tokyo, Japan. f Ocean Research Institute, University of Tokyo, Japan. g Department of Biology and Geosciences, Osaka City University, Japan. h For full details see: www.suigetsu.org * Corresponding author: gosch@gfz-potsdam.de

Assessing the importance of terrestrial radiocarbon archives for the glacial period: implications of the Suigetsu (SG06) radiocarbon record

a Research Laboratory for Archaeology and the History of Art, University of Oxford, UK. b NERC Radiocarbon Facility (Environment), East Kilbride, UK. c GeoForschungsZentrum, Potsdam, Germany. d Institute of Geography and Earth Sciences, University of Wales Aberystwyth, UK. e Institute of Geological Sciences, Freie Universitat, Berlin, Germany. f Department of Biology and Geosciences, Osaka City University, Japan. g Faculty of Policy Informatics, Chiba University of Commerce, Japan. h Department of Earth and Planetary Sciences, University of Tokyo, Japan. i Ocean Research Institute, University of Tokyo, Japan. j College of Education, Naruto University of Education, Japan. k Department of Geography, University of Newcastle-upon-Tyne, UK. l For full details see: www.suigetsu.org * Corresponding author: christopher.ramsey@rlaha.ox.ac.uk

Occurrence of nephrolithiasis in a population of longsnout seahorse,Hippocampus reidiGinsburg, and analysis of a nephrolith

1 Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria 2 Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, Vienna, Austria 3 Institute of Mineralogy and Petrography, University of Innsbruck, Innsbruck, Austria 4 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada 5 Department of Forensic Medicine, Medical University of Vienna, Vienna, Austria

Honors

Two AGU members are among the 23 new MacArthur fellows for 2012, the John D. and Catherine T. MacArthur Foundation announced on 2 October. Geochemist Terry Plank, a professor in Columbia University's Department of Earth and Environmental Sciences, was cited for “probing the usually invisible but remarkably powerful thermal and chemical forces deep below the Earth's crust that drive the motion of tectonic plate collisions.” The MacArthur Foundation cited marine ecologist Nancy Rabalais, executive director and professor at the Louisiana Universities Marine Consortium, for “documenting the environmental and economic consequences of hypoxic zones in the Gulf of Mexico and informing strategies for restoring the degraded waters of the Gulf and the Mississippi River basin.” Each fellow will each receive $500,000 in no‐strings‐attached support over the next 5 years.

Quantifying field-scale effects of elevated carbon dioxide concentration on crops

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 54:35-47 (2012) - DOI: https://doi.org/10.3354/cr01096 Quantifying field-scale effects of elevated carbon dioxide concentration on crops Eline Vanuytrecht1,*, Dirk Raes1, Patrick Willems2, Sam Geerts1 1Division of Soil and Water Management, Department of Earth and Environmental Sciences 2Hydraulics Laboratory, Department of Civil Engineering, KU Leuven University, 3001 Heverlee, Belgium *Email: eline.vanuytrecht@ees.kuleuven.be ABSTRACT: Climate change will affect crop growth and agricultural production worldwide. Crop production will be affected not only by modified rainfall patterns, increased air temperatures and changes in evaporative demand, but also elevated atmospheric CO2 concentrations ([CO2]). This study used meta-analytic techniques to quantify field-scale effects of elevated [CO2] (mainly 541 to 620 µmol mol−1) on agricultural crops in free air CO2 enrichment (FACE) conditions. Overall, crops benefit from elevated [CO2] by improving water productivity (+23% for biomass production and +27% for yield production), which is achieved through production increases in biomass (+15% for aboveground biomass) and yield (+16%), in combination with a decrease in seasonal evapotranspiration (–5%). Increased root:shoot ratios (+24%) indicate a more than proportional stimulation of belowground biomass production. Less critical, yet statistically significant are changes in canopy development rate and in phenology. Certain statistically significant differences existed between C3 and C4 crops, and between levels of environmental stress (nitrogen and water availability). Once the effect of elevated [CO2] is well understood and quantified, crop modellers can investigate the interactions with other climatic factors, providing better estimates of potential impacts on food production. KEY WORDS: CO2 · Climate change · Crop productivity · FACE · Field-scale effects · Meta‑analysis Full text in pdf format Supplementary material PreviousNextCite this article as: Vanuytrecht E, Raes D, Willems P, Geerts S (2012) Quantifying field-scale effects of elevated carbon dioxide concentration on crops. Clim Res 54:35-47. https://doi.org/10.3354/cr01096 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 54, No. 1. Online publication date: August 03, 2012 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2012 Inter-Research.

Biosignatures link microorganisms to iron mineralization in a paleoaquifer

Research Article| August 01, 2012 Biosignatures link microorganisms to iron mineralization in a paleoaquifer Karrie A. Weber; Karrie A. Weber * 1School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588, USA2Department of Earth and Atmospheric Sciences, University of Nebraska, Lincoln, Nebraska 68583, USA *E-mail: kweber2@unl.edu. Search for other works by this author on: GSW Google Scholar Trisha L. Spanbauer; Trisha L. Spanbauer 1School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588, USA †Current address: Department of Earth and Atmospheric Sciences, University of Nebraska, Lincoln, Nebraska 68583, USA. Search for other works by this author on: GSW Google Scholar David Wacey; David Wacey 3Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Crawley, WA 6009, Australia4School of Earth and Environment, University of Western Australia, Crawley, WA 6009, Australia Search for other works by this author on: GSW Google Scholar Matthew R. Kilburn; Matthew R. Kilburn 3Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Crawley, WA 6009, Australia Search for other works by this author on: GSW Google Scholar David B. Loope; David B. Loope 2Department of Earth and Atmospheric Sciences, University of Nebraska, Lincoln, Nebraska 68583, USA Search for other works by this author on: GSW Google Scholar Richard M. Kettler Richard M. Kettler 2Department of Earth and Atmospheric Sciences, University of Nebraska, Lincoln, Nebraska 68583, USA Search for other works by this author on: GSW Google Scholar Geology (2012) 40 (8): 747–750. https://doi.org/10.1130/G33062.1 Article history received: 28 Nov 2011 rev-recd: 08 Mar 2012 accepted: 12 Mar 2012 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Karrie A. Weber, Trisha L. Spanbauer, David Wacey, Matthew R. Kilburn, David B. Loope, Richard M. Kettler; Biosignatures link microorganisms to iron mineralization in a paleoaquifer. Geology 2012;; 40 (8): 747–750. doi: https://doi.org/10.1130/G33062.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Concretions, preferentially cemented masses within sediments and sedimentary rocks, are records of sediment diagenesis and tracers of pore water chemistry. For over a century, rinded spheroidal structures that exhibit an Fe(III) oxide–rich exterior and Fe-poor core have been described as oxidation products of Fe(II) carbonate concretions. However, mechanisms governing Fe(III) oxide precipitation within these structures remain an enigma. Here we present chemical and morphological evidence of microbial biosignatures in association with Fe(III) oxides in the Fe(III) oxide–rich rind of spheroidal concretions collected from the Jurassic Navajo Sandstone (southwest United States), implicating a microbial role in Fe biomineralization. The amount of total organic carbon in the exterior Fe(III) oxides exceeded measured values in the friable interior. The mean δ13C value of organic carbon from the Fe(III) oxide–cemented exterior, δ13C of −20.55‰, is consistent with a biogenic signature from autotrophic bacteria. Scanning electron micrographs reveal microstructures consistent with bacterial size and morphology, including a twisted-stalk morphotype that resembled an Fe(II)-oxidizing microorganism, Gallionella sp. Nanoscale associations of Fe, O, C, and N with bacterial morphotypes demonstrate microorganisms associated with Fe(III) oxides. Together these results indicate that autotrophic microorganisms were present during Fe(III) oxide precipitation and present microbial catalysis as a mechanism of Fe(III) oxide concretion formation. Microbial biosignatures in rinded Fe(III) oxide–rich concretions within an exhumed, Quaternary aquifer has broad implications for detection of life within the geological record on Earth as well as other Fe-rich rocky planets such as Mars, where both Fe(II) carbonate and Fe(III) oxide–rich concretions have been identified. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.