The petrology and geochemistry group at the Jackson School explores a wide range of research topics. Faculty are working on mantle geochemistry; magma dynamics and eruption; metamorphic textures and reactions; and ore deposits from basinal, metamorphic, or magmatic fluids.

Some of the questions that motivate research in this area are: How do rocks, minerals, and melt of Earth's deep crust and upper mantle record their geological histories in their textures, chemical and isotopic compositions, mineral compositions and zoning? To what extent do equilibrium processes operate in deep crustal and magmatic environments, as opposed to kinetically-controlled disequilibrium processes? How do magmas form, and what do they tell us about the mantle?

One line of research focuses on the physical and chemical aspects of volcanic eruptions and magmatic processes. One facet of this research involves studying active volcanic centers, including volcanoes in the U.S., Mexico, Nicaragua, Russia, and many other countries, and their volcanic deposits in order to better understand eruption processes, long-term eruptive behavior, and volcanic hazards to humans. Another facet utilizes experimental petrology to determine the pre-eruption contents of volatiles in magmas, the degassing of those volatiles from magmas, the control that volatile degassing has on volcanic eruptions and formation of ore bodies, and the impact that volcanic gases have on local and global climate.

Another line of research involves developing a quantitative understanding of the rates and mechanisms of metamorphic processes. For example, researchers are quantitatively analyzing primary metamorphic microstructures, linked to numerical simulations of their development, to understand fundamental processes of recrystallization. The greatest novelty in this work is the use of high-resolution X-ray computed tomography (HR X-ray CT) to reveal the sizes, shapes and disposition of crystals within a rock.

Research also focuses on the chemical and isotopic compositions of magmas, mantle xenoliths, and other geologic materials to understand how melts are generated in the mantle and how subduction of crust and sediments has effected the long-term chemical and physical evolution of the Earth’s interior. Geochemical research in the department includes projects examining the nature and origin of mantle plumes and the global cycling of volatiles in the Earth.

Research on hydrothermal systems integrates mineralization into a broad framework involving fluid and isotope geochemistry, petrology, tectonics, and geochronology. Long-term studies include pluton- and wallrock-hosted Cu-Au mineralization in the Ertsberg district in the Central Ranges of New Guinea. Exciting new perspectives are coming from quantitative X-ray computed tomography study of three-dimensional distribution of gold in ores, as well as providing unique information on fluid inclusions in opaque minerals.

Graduate students at the Jackson School can explore a wide range of processes from theoretical, experimental, and applied perspectives, and greatly benefit from the diverse studies in the group and one of the best equipped research groups in the country.

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• Northern Mexico: volcanology, petrology, geochemistry, and mineralization.
• Physics of explosive volcanic eruptions; transport and depositional processes in pyroclastic flows
• Trans-Pecos Texas: petrogenetic development, mineralogy, isotope geology, and mineralization.
• Southwestern US: Cenozoic volcanic rocks, peridotite and eclogite inclusions, and relations to tectonic patterns.
• Igneous and metamorphic processes in the Rocky Mountains and Basin and Range.
• Llano region, Texas: petrologic, structural, and geochronologic studies of Precambrian igneous and metamorphic rocks.
• Antarctica: structure, petrology, geochronology, and isotope geochemistry.
• Application of high-resolution X-ray computed tomography to orebody genesis and mineral processing issues; quantitative textural analysis of gold distribution in ores; fluid inclusions in opaque minerals
• Ore deposits: New Guinea porphyry-skarn Cu-Au deposits; stratabound mineral deposits; industrial minerals; fossil geothermal systems; fluid-inclusion and isotopic studies.
• Laboratory studies: mineral systems, geothermometry, geochronology, isotope geology, and hydrothermal processes.
• Theoretical studies: diffusion; subduction zone mechanics; pressure solution; evolution of magma sources; mineral stability and thermodynamic models; fission track annealing.

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Researchers and students working in this area have access to a vast array of equipment including: an electron microprobe, a high-resolution X-ray CT scanner (the first of its kind in an academic department in the world), two scanning electron microscopes, two ICP-MS (inductively coupled plasma mass spectrometers) for trace element and isotope analyses, thermal ionization mass spectrometer (TIMS), a Thermo Electron 6700 Fourier Transform Infrared (FTIR) spectrometer coupled with a Nicolet Continuum IR microscope and complete glass inclusion laboratory, and an X-ray diffractometer.

The department also houses several Class 100 Geochemistry clean labs used to prepare samples for analysis in ultra-clean environments. Researchers in the department utilize a wide range of radiogenic isotope systems as research tools to provide age determinations of magmatic and tectonic events and to provide geochemical tracers to study processes such as crustal recycling and core/mantle interactions.

The department runs a High Temperature Experimental Petrology Laboratory that is equipped with cold-seal pressure vessels, some of which are designed for rapid quench capabilities, phase equilibria furnaces, and one-atmosphere gas-mixing furnaces. Experiments ranging from 700 to 1250 degrees C and from one atmosphere to 5000 bars are possible to explore phase equilibria and kinetic reactions in magmas.

Importantly, graduate students have easy access to and are encouraged to use all equipment housed in the Jackson School, most free for use.

• Department of Civil Engineering: Earthquake engineering program, laboratories, and facilities.
• Department of Petroleum Engineering: Rock Mechanics laboratory, well logging studies.
• Center for Space Research: Earth gravity, geoid studies, satellite geodesy, remote sensing.
• Applied Research Laboratory: Underwater acoustics; sound interaction with ocean bottom.
• McDonald Observatory: Lunar and satellite laser ranging facility.
• Bureau of Economic Geology: Core Repository.
• Marine Science Institute/Department of Marine Studies: Research vessels and facilities on the Texas Gulf Coast.

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• More about graduate admissions & support

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