T18 Features, Processes, and Emplacement of Melted Rock on the Earth and Planets—A Session in Honor of Christopher W. Hamilton, Recipient of the MGPV Early Career Award

Sunday, 4 November 2018
8:00 AM - 12:00 PM
Room 243

SPECTRAL ANALYSIS OF EXPLOSIVE AND EFFUSIVE VOLCANISM IN THE MARIUS HILLS VOLCANIC COMPLEX

Paper number: T18-8
Program: Technical Sessions
Time: 9:50 AM – 10:05 AM

Authors

Abstract

The Marius Hills Volcanic Complex (MHVC; 13.3ºN, 47.5ºW) is a 35,000 km2 plateau that extends 100-200 m above the surrounding plains of Oceanus Procellarum and contains a wide assortment and unusual concentration of volcanic features. These volcanic features include volcanic domes, lava flows, sinuous rilles, and volcanic cones. The volcanic cones in the MHVC were identified initially using visible imagery based on morphologies similar to cinder cones on Earth. Lawrence et al. (2013) completed a morphological survey of the cinder cones of the MHVC, identifying 93 possible cinder cones and 55 ambiguous circular structures. A definitive designation of a cinder cone would require evidence that the volcanic edifice was constructed of ballistic glass-rich pyroclasts from an explosive, volatile-rich eruption. A previous analysis using Moon Mineralogy Mapper (M3) orbital visible/near-infrared (VNIR) spectra was not able to spectrally distinguish the volcanic cones from the underlying domes; however, new techniques for detecting glass in VNIR spectra have since been developed. This research will answer the question: Is glass present in the MHVC, and can glass signatures be used to confirm the distribution and explosive origin of the MHVC cones?

Using the M3 data, we show that the volcanic cones within the MHVC exhibit spectra that are distinct from the underlying domes that are consistent with the presence of significant glass. Mapping glass in the region reveals that the shape and orientation of the volcanic cones in M3 maps mirror the visible imagery. The matching shapes indicate that the volcanic cones are glass-rich, as expected in an explosive eruption resulting in cinders. In response to the success to finding glass spectral signatures in known volcanic cones, we have applied the method to the 55 ambiguous circular structures to confirm or deny cone designation.

Spectral analysis of the MHVC can increase the known amount and the extent of volcanic cones, which require a higher volatile contribution for formation than the other volcanic features in the region. When all the cone locations are mapped, a trend in the distribution of the features may indicate the presence of rift zones, help track the past movement of magma through the region, and give insight to the volcanic and volatile history of the volcanic complex.

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-321659

© Copyright 2018 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.