GMU Paleomagnetism Laboratory

The Environmental Science and Policy Department at George Mason University has a fully functional paleomagnetism laboratory capable of paleomagnetic and rock magnetic studies of geologic materials for a variety of applications.

Some of the projects in which the laboratory is currently involved include:

• Structural and tectonic studies of folded sills in the Helena salient of the Montana thrust belt in order to determine timing of contractional deformation

• Paleomagnetic and geochronologic studies of Precambrian rocks from the western U.S. in order to determine improved paleomagnetic pole positions for the North American craton and testing of various proposed Precambrian plate reconstructions

• Paleomagnetic and rock magnetic studies of Tertiary and Quaternary volcanic rocks in Yellowstone National Park and surround areas

• Sediment magnetic studies of soils and loess parent materials from the U.S. midcontinent in order to evaluate possible links between magnetic susceptibility and climate change

• Paleomagnetic and rock magnetic studies of Jurassic/Triassic and Tertiary intrusive rocks in northern and central Virginia

• Paleomagnetic studies of Tertiary volcanic rocks from the Cerrillos Hills and surrounding areas, New Mexico; testing for possible vertical axis rotations associated with the development of the Rio Grande Rift

Instrumentation and Equipment

1) An AGICO JR5A spinner magnetometer interfaced with a microcomputer for on-line data acquisition and reduction.

2) A D-Tech/ASC Scientific static alternating field demagnetizer capable of generating a peak field of 200 mT.

3) An ASC Scientific TD48-SC thermal demagnetizer capable of handling a total of 96 paleomagnetic specimens (48 heating; 48 cooling).

4) An AGICO KLY3S spinner Kappabridge and CS-3 temperature unit for measurement of anisotropy of magnetic susceptibility and variations in magnetic susceptibility as a function of temperature

5) An ASC Scientific impulse magnetizer capable of a peak induction of about 1.2 T

6) A Pomeroy portable rock drill and associated orientation and field sampling equipment.

Photographs of the Laboratory and Instruments

AGICO JR5A spinner magnetometer.

AGICO JR5A spinner Magnetometer showing removal of magnetic shielding and automated specimen holder.

AGICO JR5A spinner magnetometer electronics.

AGICO KLY3-S spinner Kappabridge and thermal demagnetization unit.

DTech alternating field demagnetizer.

ASC Scientific TD-48 Thermal specimen demagnetizer and temperature control unit.

Use of the Paleomagnetic Facilities

The GMU facilities are available to guest researchers from academic, government, and professional institutions and agencies in the metropolitan D.C. area. Please contact Stephen S. Harlan for details.

Research Funding

Funding for the acquisition and maintenance of the lab has been provided by George Mason University and a grant from the National Science Foundation’s Instrumentation and Facilities Program (NSF EAR-0087556).

Photographs from Field Projects and Field Trips

Northern Virginia

Cerrillos Hills, NM

Paleomagnetism of Proterozoic mafic dikes in western North America