Paleoclimate and Paleoenvironmental Change
The UC Davis Earth and Planetary Sciences department has outstanding facilities to support work done in sedimentology, stratigraphy, paleoceanography, paleomagnetism, and low temperature geochemistry. In-house light stable isotope ratio mass spectrometers include Fisons Optima and Finnigan MAT 251 mass spectrometers with automated capabilities for analyzing carbon and oxygen isotope ratios on very small carbonate samples, carbon and nitrogen isotope ratios on organic matter, and oxygen and hydrogen isotope ratios on waters. A third continuous flow stable isotope mass spectrometer is available for sulfur isotope analyses; and a fourth IsoPrime IRMS can analyze carbon and oxygen isotopes in carbonates in dual inlet mode as well as analyzing microliter-sized water samples and organic matter (for H and O isotopes) and oyxgen isotopes on minerals such as phosphate, nitrate and sulfate (O isotopes) in continuous flow mode. Off line isotopic separation facilities include vacuum lines for carbonates, organic carbon, total CO2 in water, hydrogen and oxygen in silicates, and sulfur in sulfides and sulfates.
A fully equipped paleomagnetics laboratory, including two SQUID magnetometers and various equipment to characterize magnetic properties, is also available in the Earth and Planetary Sciences department. A scanning electron microscope with EDS X-ray and image processing capabilities is available, as well as a fully automated CAMECA electron microprobe; and the Davis campus has recently installed a state of the art multi-collector ICP-MS (Nu Plasma HR) and two quadrupole ICP-MS (Agilent Technologies 7500a and 7500c) and a laser ablation system (New Wave Research UP-213) for trace element and radiogenic isotope measurements. Additional research facilities include a cathodoluminescence microscope, an epi-fluorescence reflected light microscope, various petrographic (including reflected light) microscopes, a fluid inclusion heating and freezing stage, and X-ray fluorescence and diffraction spectrometers. The Earth and Planetary Sciences department also has a well supported, in-house computing network and a microcomputer laboratory for research and teaching.
Groundwater contaminant transport; groundwater basin characterization and management; geologic/geostatistical characterization of subsurface heterogeneity for improved pollutant transport modeling; numerical modeling of groundwater flow and contaminant transport; role of molecular diffusion in contaminant transport and remediation; long-term sustainability of regional groundwater quality; vulnerability of aquifers to non-point-source groundwater contaminants.
Research areas include marine micropaleontology, geological oceanography, and paleoceanography utilizing geochemistry of marine sediment and coral records. Tessa is also involved in interdisciplinary research to investigate the impacts of ocean acidification on coastal California environments. Research in her laboratory includes:
- Culturing of key species in the laboratory under controlled environmental conditions
- Monitoring modern pH variability on the Northern California coast using pH sensors and oceanographic transects
- Reconstructing climate variability utilizing geochemical proxies in foraminifera, corals, and other carbonates
- Investigating coastal environments to understand potential for carbon storage
Research interests are in the sedimentary record of coupled physical and chemical variation in paleo-oceans, global biogeochemical cycling in marine and terrestrial records, and carbonate fluid-rock interaction in sedimentary basins using stratigraphy, petrography and geochemistry, including stable and radiogenic isotopes and trace elements. Research in the laboratory broadly focuses on development of quantitative paleoclimate proxies, and their application to intervals of time characterized by major and/or abrupt climate change including past periods of icehouse-to-greenhouse transitions through to the last deglaciation.
Early terrestrial atmospheres, magma oceans and the early volatile history of Earth, chemical evolution of the mantle-crust-atmosphere system, application of surface exposure dating to understanding land surface evolution, novel techniques for reconstructing mineral dust emission from continents and climatic effects of mineral dust, sediment mass accumulation rates from extraterrestrial helium-3.
Stratigraphy and sedimentology applied to paleoenvironments, paleoceanography and paleolimnology. Research interests include orbital stratigraphy, sea-level history, carbonate platform evolution, petrophysical heterogeneity of hydrocarbon reservoirs, lacustrine sedimentation and paleoclimatology. Current projects include the relationship between Sr isotopic content of the oceans and sea-level chronology, the global climatic significance of episodes of oceanic anoxia recorded in Cretaceous carbonates of northeastern Mexico, and the paleoclimate history of the High Sierra as deduced from Lake Tahoe sediment cores.
Pinter's research focuses on earth-surface processes (geomorphology) applied to a broad range of problems. Much recent work involves rivers, fluvial geomorphology, flood hydrology, floodplains, and watersheds. His research group applies fluvial geomorphology, hydrologic and statistical tools, hydraulic modeling, and other approaches to assess river dynamics and flood hazards. Although much current research focuses on rivers, he continues to work on a broad range of processes that shape the earth surface and operate.
Stable isotope and trace metal geochemistry, paleoclimatology, marine micropaleontology, and paleoceanography. Research focuses on the biological and environmental parameters that affect the stable isotope and trace metal geochemistry of the shells of recent and fossil organisms; paleoclimatology, marine micropaleontology, and paleoceanography.
Sumner reconstructs ancient environments across Earth history and on Mars. Her lab group uses stratigraphic, sedimentological, and petrographic studies of carbonate sequences to reconstruct ancient environments and ocean chemistry to better understand microbial life on Earth. They use the Mars Science Laboratory to develop environmental and stratigraphic models for strata in Gale Crater, Mars, to understand its past habitability. In addition, the group applies diverse techniques to understand the effects of recent climate change on photosynthetic microbial communities growing in ice-covered Antarctic lakes.
Busby's current research is on late Cenozoic transtensional rift tectonics and volcanology of the Sierra Nevada/Walker Lane and the Gulf of California, as well as an accreted oceanic arc terrane in Baja California, with comparisons to modern oceanic arcs. Cathy’s research is based on detailed geologic mapping of volcanic terranes, supported by petrographic, geochemical, geochronological, paleomagnetic and mineral chemistry data.
Fluvial geomorphology, ecogeomorphology, river and water resource analysis. Research emphasis on the geomorphology and ecology of rivers and streams, their response to changes in land use/land cover and flow regulation, and their restoration and assessment. Projects include restoration of river floodplains, management of levee systems in floodplain/estuary systems, re-operation of hydropower systems to improve aquatic ecosystems and adapt to climate change, and restoration of spring fed streams and meadow systems.
For much of his career, Ken Verosub has used the magnetic properties of rocks, sediments and soils to determine the behavior of the Earth's magnetic field, the ages of sedimentary sequences, the motions of tectonic plates, and the history of the Earth's climate during the past 40 million years. In addition to on-going paleomagnetic and environmental magnetic studies, he is working on volcanic eruptions that have caused global cooling, seismic risk and subsidence problems in the Sacramento-San Joaquin Delta, the identification of deep groundwater aquifers and the determination of river flows directly from geospatial imagery.
Aqueous geochemistry; stable isotope geochemistry; economic geology. Research has focused on water/rock interaction in active and ancient hydrothermal systems, including the "black smokers" on the mid-ocean ridges. Research topics include the geology and geochemistry of sulfide deposits and hydrothermal alteration in seafloor hydrothermal systems and on-land analogs.