Micro Sampling Facility
We are equipped to micro-sample geologic
materials to sub-micron scale. At present, we operate two complementary
micro-sampling devices:
- The Microdrill
A microdrill which can sample disks of materials as small as
10 microns and as large as 2 mm in diameter. The unit is mounted on a
conventional petrographic microscope. Drilling can be performed on thin or
polished sections. The material is recovered in cylinder-shaped solid pieces.
We use this to sample mineral grains as well as glass inclusions from
mantle-derived rocks. We have successfully drilled silica-rich glass inclusions
from peridotite xenoliths and measured their oxygen isotopic compositions.
- The Micromill
Former student Erin Rosenberg
viewing a sample on the micromill
This product, which is
manufactured by Merchantek-NewWave Research, is truly the state of the art in
high-resolution micro sampling. The Micromill can extract materials as small as
1/4 micron. We use this instrument to recover sample power for chemical and
isotopic analysis. The combination of submicron stage resolution and positional
accuracy, real-time video observation and a custom designed software system
allows for sampling of complex crystalline materials. One of the most important
features is the computer routine for interpolation subsampling paths and on
screen display of digitized and interpolated sampling paths. This allows the
sampling to be conducted automatically on pre-determined paths, no matter how
complicated. Transmitted and reflected light microscopy can be used for
sampling. We are using the Micromill to primarily to
sample inclusion-free garnet fractions for Sm-Nd isotopic analyses.
The micro-sampling laboratory is located
in Gould-Simpson Room 539, and is open to any interested users on campus.
Please contact Dr. Mihai Ducea for further details. Supported by NSF Grant 0140607.