Geological Society of America

66 Volcanology (Posters)

Tuesday, 25 March 2014
8:00 AM - 12:00 PM
Freedom Hall A

BASIC PALEOMAGNETIC PROPERTIES OF OBSIDIAN FROM THE MOUNT TAYLOR REGION OF NEW MEXICO

Paper number: 66-2
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Michaela Kim Presenting Author
Mount Holyoke College, South Hadley, MA
Robert S. Sternberg
Franklin & Marshall College, Lancaster, PA
Laurie Brown
Univ Massachusetts - Amherst Dept Geosciences- Morrill Sci Ctr, Amherst, MA
Joshua M. Feinberg
John T Tate Hall Rm. 150, Minneapolis, MN
M. Steven Shackley
University of California, Berkeley, Berkeley, CA

Abstract

Mount Taylor has three main obsidian deposits: Grant’s Ridge, Horace Mesa, and La Jara Mesa. The obsidian found at Grant’s Ridge was formed in a rhyolite dome and can be found in a perlite wall as well as in float down the side of the outcrop. The obsidian at both Horace and La Jara mesa is found as float on top of underlying basalt.

We collected geo-referenced samples from each of these localities. I cut and prepared the samples for basic paleomagnetic tests. I ran susceptibility and AF demagnetization on all samples. Additionally I measured the NRM and IRM of my prepared samples. Based on these magnetic properties of my obsidian samples, I analyzed them looking for variations in the magnetic properties both within each individual site and between the three different localities. Being able to distinguish both between the different localities and within the individual quarries may help to further understand and source archaeological objects made of obsidian from this region.