A5040439570- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Hydrocarbon exploration and reservoir analysis
- Evolution and Paleontology Studies
- Geological Studies and Exploration
- Geological and Geochemical Analysis
- Geological formations and processes
- Geochemistry and Geologic Mapping
- Paleontology and Evolutionary Biology
- Geochemistry and Elemental Analysis
- Methane Hydrates and Related Phenomena
- Isotope Analysis in Ecology
- Botany, Ecology, and Taxonomy Studies
- Geological and Geophysical Studies
- Greenhouse Technology and Climate Control
- Groundwater and Isotope Geochemistry
- Archaeology and Natural History
- Atmospheric and Environmental Gas Dynamics
- Pleistocene-Era Hominins and Archaeology
- Geological Modeling and Analysis
- Plant Diversity and Evolution
- Marine Biology and Ecology Research
- Fish biology, ecology, and behavior
- Mathematics Education and Programs
- earthquake and tectonic studies
University of Kansas
2009-2024
The University of Texas at San Antonio
2013-2021
Johns Hopkins University
2011-2014
Temple University
2007
Abstract The Yellow River transports a large amount of sediment and particulate organic carbon (POC), which is thought to mainly derive from erosion the Chinese Loess Plateau (CLP). However, compositions, sources erosional fluxes POC in remain poorly constrained. Here we combined measurements mineralogy, total content (OC ), stable isotopes (δ 13 C org radiocarbon ( 14 C) activity matter bulk suspended sediments collected seasonally upper middle River, quantify compositions assess its...
Research Article| July 01, 2015 ENVIRONMENTAL CONTROLS ON THE GENESIS OF MARINE MICROBIALITES AND DISSOLUTION SURFACE ASSOCIATED WITH END-PERMIAN MASS EXTINCTION: NEW SECTIONS OBSERVATIONS FROM NANPANJIANG BASIN, SOUTH CHINA DANIEL J. LEHRMANN; LEHRMANN 1Geoscience Department, Trinity University, San Antonio, Texas 78212, USA e-mail: dlehrmann@trinity.edu Search for other works by this author on: GSW Google Scholar JOHN M. BENTZ; BENTZ TANNER WOOD; WOOD ALEXA GOERS; GOERS RYAN DHILLON;...
Research Article| December 01, 2011 Paleosol carbonate multiple isotopologue signature of active East Asian summer monsoons during the late Miocene and Pliocene Marina B. Suarez; Suarez * 1Department Earth Planetary Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA †Present address: Department Geological University Texas, 1 UTSA Circle, San Antonio, Texas 78249, *E-mails: msuarez5@jhu.edu; bhpassey@jhu.edu; anu.kaakinen@helsinki.fi. Search for other works by this author on:...
Abstract Two sections from Early Cretaceous lacustrine strata of the Xiagou Formation Changma Basin in Gansu Province, China, are correlated based on their carbon isotopic compositions bulk sedimentary organic matter and carbonate, as well carbonate oxygen-isotopic compositions. The samples were collected fossiliferous strata, which contain well-preserved bird remains. primarily a two-step increase δ 13 C org with an overall magnitude c. 12.5‰. stratigraphic variations isotopes within two...
Although only recognized as a discrete stratigraphic unit since 1944, the Cedar Mountain Formation represents tens of millions years geological and biological history on central Colorado Plateau. This field guide an attempt to pull together results recent research lithostratigraphy, chronostratigraphy, sequence stratigraphy, chemostratigraphy, biostratigraphy these medial Mesozoic strata that document dynamic complex this region. Additionally, data provide framework by which examine...
Research Article| November 01, 2009 Isotopic composition of low-latitude paleoprecipitation during the Early Cretaceous Marina B. Suarez; Suarez † 1Department Geology, University Kansas, 1475 Jayhawk Blvd., Lawrence, Kansas 66045, USA †E-mail: msuarez@ku.edu. Search for other works by this author on: GSW Google Scholar Luis A. González; González Gregory Ludvigson; Ludvigson 2Kansas Geological Survey, 1930 Constant Ave., 66047, Francisco J. Vega; Vega 3Instituto de Geología, Universidad...
Speleothem 13 C has been taken as an indicator of the history rocky desertification, and changes in have thought to reflect transition between C3 C4 surface vegetation types.In this study values plants, soil organic matter (SOM), dissolved inorganic carbon (DIC) waters modern calcite deposits caves were investigated at five sites with different desertification degree (RDD) Southwest China.The main results can be summarized follows: (1) dominant was type, average plant ranging from 26 ‰...
The Cloverly Formation of Montana and Wyoming preserves abundant nonmarine vertebrate fossils from the mid-Cretaceous, yet its paleoenvironment faunal niche structure remain poorly understood. We analyzed δ 18 Ο phosphate in over 100 fossil individuals multiple taxa collected a single microfossil bonebed Carbon County, Montana.To infer habitat preferences water-use strategies, we compared values within across taxa. reconstructed O surface_water semi-aquatic reptile using regressions...
The Crystal Geyser Dinosaur Quarry contains a large monospecific accumulation of bones from basal therizinosaur, Falcarius utahensis.The quarry is located approximately 16 km south Green River, Utah, at the base early Cretaceous (Barremian) Yellow Cat Member Cedar Mountain Formation.Fossil in occur three units that have distinct taphonomic, lithologic, and geochemical characteristics.Rare earth element compositions fossils suggest each unit were drawn different reservoirs or sources having...
Abstract This paper presents breakthroughs in the chronostratigraphy of heretofore poorly constrained Yellow Cat Member Cedar Mountain Formation, which is an important record terrestrial environments, ecosystems and global change ancient North American Cordilleran foreland. Zircon populations from 10 stratigraphic horizons yield youngest single-grain ages ranging 142.5 ± 2.7 to 133.7 Ma (Berriasian–late Valanginian); those one mudstone palaeosol a robust Concordia Age 136.3 1.3...
Abstract Recent studies utilize the oxygen isotopic composition of pedogenic carbonates (siderite and calcite) to evaluate empirically global hydrologic cycle during Cretaceous. Pedogenic are used as a proxy for meteoric waters in order estimate precipitation rates Aptian–Albian via mass-balance model. These modeling have previously been limited mid-latitude high-latitude data, thus more extensive latitudinal data set is needed produce globally constrained This study provides an equatorial...
The Ghalilah Formation, UAE provides a complete and continuous equatorial shallow-water carbonate sequence through the Upper Triassic to Lower Jurassic interval. In higher latitudes, this interval is frequently associated with widespread ocean acidification evidenced by lack of carbonates or hiatus in deposition. data presented here contrast show evidence for aragonite supersaturation at Triassic–Jurassic boundary Tethys. δ 13 C carb shows characteristic negative excursion values as low...
Although only recognized as a discrete stratigraphic unit since 1944, the Cedar Mountain Formation represents tens of millions years geological and biological history on central Colorado Plateau. This field guide an attempt to pull together results recent research lithostratigraphy, chronostratigraphy, sequence stratigraphy, chemostratigraphy, biostratigraphy these medial Mesozoic strata that document dynamic complex this region. Additionally, data provide framework by which examine...
Abstract: The Lower Cretaceous strata of Asia are renowned for abundant fossil resources. These can also offer a wealth quantitative data regarding the paleoclimate and paleoenvironment terrestrial Cretaceous, an important transition in Earth history. Many modern groups organisms that dominate ecosystems today originated or expanded Early Cretaceous. In addition, Period, known to have been characterized by greenhouse climate, provides opportunities understand how climate system functioned...
The Early Cretaceous Yellow Cat Member of the terrestrial Cedar Mountain Formation in Utah, USA. has been interpreted as a “time-rich” unit because its dinosaur fossils, prominent paleosols, and results preliminary chemostratigraphic geochronologic studies. Herein, we refine prior interpretations with: (1) new composite C-isotope profile from well-known Utahraptor Ridge site, which exhibits δ13C features tentatively Valanginian double-peak carbon isotope excursion (the so-called “Weissert...
The Early Cretaceous of northwest China has yielded abundant vertebrates, invertebrates, and plant fossils from numerous intermontane basins. Developing a chronostratigraphic context for these important fossil finds is to understanding the development modern terrestrial ecosystems, evolution dinosaurs, greenhouse climate. This study utilizes carbon isotope chemostratigraphy fossil-rich Xinminpu Group in Yujingzi Basin Gansu Province. Lithostratigraphic descriptions defined three facies....
Auroraceratops rugosus from the Lower Cretaceous Zhonggou Formation, Gansu Province, China is characterized by exquisite external preservation of articulated, often ventrolaterally curled remains found in discrete locations several to hundreds meters apart. This has prompted a hypothesis that are result recurring die-offs and rapid burial burrows. To test this, rare earth element (REE) concentrations were measured bones surrounding red-bed mudstones via inductively coupled plasma mass...
Lanzhousaurus magnidens, a large non-hadrosauriform iguanodontian dinosaur from the Lower Cretaceous Hekou Group of Gansu Province, China has largest known herbivorous teeth. Unlike its hadrosauriform relatives possessing tooth batteries many small teeth, utilized number (14) very teeth (~10 cm long) to create large, continuous surface for mastication. Here we investigate significance in evolutionary history iguanodontian-hadrosauriform transition by using combination stable isotope analysis...
Abstract. The Early Cretaceous is characterized by warm background temperatures (i.e., greenhouse climate) and carbon cycle perturbations that are often marked ocean anoxic events (OAEs) associated shifts in the hydrologic cycle. Higher-resolution records of terrestrial marine δ13C δ18O (both carbonates organics) suggest climate during Aptian–Albian, including a period with OAE 1a early Aptian subsequent “cold snap” near Aptian–Albian boundary prior to Kilian 1b. Understanding continental...