University of Minnesota
University of Minnesota
David Kohlstedt

Department of
Earth Sciences

Rock and Mineral Physics Lab



Above is the workhorse of our rock deformation laboratory, a gas-medium deformation apparatus. Designed and built by Mervyn Paterson, this rig has been in use since 1991. We have performed over 1400 runs in it, making us one of the most productive rock deformation labs in the world. In this vessel, we can deform samples in either pure or simple shear, and apply either a constant load to the sample, or a constant actuator displacment rate, which approximates a constant strain rate. Experiments are typically done at temperatures ranging from 1100 - 1300 C, and confining pressures of 200 - 400 MPa.
We received a second Paterson apparatus in the summer of 2002, making us the only rock deformation laboratory in the U.S. with two of these rigs. This new unit is capable of deforming samples in torsion. By twisting the sample from above with a torsion actuator (lower picture) we can explore theoretically unlimited strains.
1-Atm rig
Deformation-DIA (D-DIA). The D-DIA is a solid-medium deformation apparatus which combines the high-pressure technology of a multi-anvil apparatus with the careful creep control of a triaxial gas apparatus. At a given confining pressure generated by six anvils, the top and bottom anvils can be moved independently to impose the desired deformation. The D-DIA is capable of deforming samples under pressures up to 15 GPa and temperatures up to 2000 K.
Our lab is equipped with a Zeiss Axio Imager M1 for relfected and transmitted light microscopy. The Axio Imager has a motorized stage and computer interface that allows the creation of high-resolution photomosaics, topographic images for surface analysis, and 3-D time-lapse projects.
FTIR is commonly used to characterize the amount of water in our samples. We share a Bruker Hyperion 2000 unit with the experimental petrology research group. The unit includes the Bruker 670 Hyperion infrared microscope with video observation in transmitted and reflective light. The adjustable aperture size allows areas as small as 10 microns to be analyzed.
Available for use by anyone properly trained and certified, a JEOL 6500 field emission gun scanning electron microscope is housed at the University's Characterization Facility. Here, high resolution images of samples can be obtained, and with the HKL Technology Channel 5 software, we can detect and quantify any crystallographic preferred orientations (CPO) in our samples
Ion thinner
X-ray diffractometer
  research themes
  Prof. David L. Kohlstedt
  Dept. of Earth Sciences
  University of Minnesota
  310 Pillsbury Dr. SE
  Minneapolis, MN 55455
  Phone: (612) 626-1544
  Fax: (612) 625-3819
  dlkohl at

  last modified
  November 21, 2010