Northeastern Section - 49th Annual Meeting (23–25 March)

Paper No. 4
Presentation Time: 1:30 PM-4:15 PM

CRACKS IN INFLATION FEATURES OF THE MCCARTYS LAVA FLOW, ZUNI-BANDERA VOLCANIC FIELD, NEW MEXICO, AND POTENTIAL APPLICATIONS TO THE ELYSIUM VOLCANIC PROVINCE, MARS


WISE, Charles, Earth Science and Geography, Vassar College, 124 Raymond Ave, Poughkeepsie, NY 12604, DE WET, Andrew P., Earth & Environment, Franklin & Marshall College, PO Box 3003, Lancaster, PA 17604-3003, HAMILTON, Christopher W., Planetary Geodynamics Laboratory, NASA Goddard Space Flight Center, Code 698, Greenbelt, MD 20771, GARRY, W. Brent, NASA, Goddard Space Flight Center, Greenbelt, MD 20771, MCHALE, Jessica C., Geology, Mount Holyoke College, 50 College Street, South Hadley, MA 01075 and KONKOL, Susan, Geological Sciences and Engineering, University of Nevada, Reno, NV 89557, chwise@vassar.edu

Substantial series of cracks are observed in the Lava Falls area on the southern edge of the McCartys Lava flow, part of the Zuni-Bandera Volcanic field in New Mexico. The topographic features of Lava Falls displaying the crack series, specifically monoclines, plateaus, and depressions, are interpreted as being formed by inflation of pahoehoe flows, as evidenced by uniformity in height, squeeze-out blades, large en echelon cracks at the flow margins, and monoclinal tilting. Crack types fall into three approximate categories: 1) planar, with one main horizontal fracture near the top, hinge-like, 2) concave with concentric, similar-sized fractures, and 3) convex, polygonal plates, fractures in all directions.

Field observations of cracks suggests a dominance of a particular category for specific topographic features of the flow. Plateau edges and monoclines are dominated by type 1 cracks, specifically horizontal fractures resembling hinges, while depressions exhibit type 2 cracks that are concentric. Numerous transects of the area were taken using a differential GPS unit linked to field measurements of crack widths and depths. Early interpretations of the data suggest the current categorization of cracks is acceptable and possible relationships between crack depths and widths and their locations on the flow. Depending on the success of this interpretation, application to suspected inflation features within the Elysium Volcanic Province of Mars is desired.