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Dr.
Richard Ketcham
Senior
Research Scientist
Area of Expertise: Field Geology, Structural
Geology and Tectonics
Short Biography:
Dr. Ketcham's primary research
responsibility is running the high-resolution X-ray computed tomography
facility (UTCT). Basically the industrial version of a medical CAT
scanner, UTCT hosted the first such device in a science department in
the world, and it remains the most versatile and powerful for many
applications. The scanner allows highly detailed, three-dimensional,
non-destructive imaging of the interiors of dense objects (rocks,
fossils, meteorites, etc) with 2-3 orders of magnitude better resolution
than possible with medical systems. In addition to operating the
scanner in support of studies by local and visiting students and
scientists, Dr. Ketcham conducts research to “mine” CT data sets for
quantitative data for use across several geological disciplines. Current
and ongoing projects include measuring discrete components within a
specimen volume (such as clasts, crystals, mineral grains, fluid
inclusions, vesicles) to determine their locations, sizes, shapes,
orientations, and contact relationships; quantifying three-dimensional
fabrics such as mineral foliations and trabecular bone; and measuring
fracture roughness and porosity/permeability networks.
Dr. Ketcham also works on the theory and practice of apatite
fission-track (AFT) thermochronology, and thermal history inverse
modeling from AFT, (U-Th)/He, and vitrinite data. Recent research has
concentrated on improving the resolution and reproducibility of
fission-track data by taking track orientation with respect to
crystallographic angle into account. His computer programs for inverse
modeling, AFTSolve and HeFTy, are widely used in academia and industry.
Another research direction has been to study the thermal structure of
continents, by examining the amount and distribution of radioactive
heat-producing elements in the crust of the Basin and Range and relating
it to regional heat flow patterns. The amount and distribution of
crustal heat production remains one of the “great unknown” geophysical
parameters, which is crucial for deriving temperatures inside the Earth
from first principles.
Dr. Ketcham is also working on improved numerical depiction of
diffusion-controlled crystal growth during prograde metamorphism on
geological time scales, in collaboration with William Carlson. This
model is aimed at utilizing measured size and spatial distributions and
zoning patterns of porphyroblasts in metamorphic rocks to determine the
values of kinetic parameters (such as activation energies for crystal
nucleation and intergranular diffusion) that are impossible or difficult
to observe at laboratory time scales.
Contact Information:
Office: 1.120CC
Phone: 512-471-6942
FAX: 512-471-9425
Email: ketcham@mail.utexas.edu
Mailing Address:
Department of Geological Sciences C1100
The University of Texas at Austin
Austin, Texas 78712
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