Mapping Stratigraphy and Anomalies in Iron-Rich Volcanoclastics Using Ground-Penetrating Radar: Potential for Subsurface Exploration on Mars | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Mapping Stratigraphy and Anomalies in Iron-Rich Volcanoclastics Using Ground-Penetrating Radar: Potential for Subsurface Exploration on Mars

Type de publication:

Journal Article

Source:

AGU Fall Meeting Abstracts, Volume 43, p.0905 (2004)

URL:

http://adsabs.harvard.edu/abs/2004AGUFM.P43A0905H

Mots-clés:

Etudes spatiales et planétologie ; 8404 Ash deposits; 6094 Instruments and techniques; 6949 Radar astronomy; 6969 Remote sensing, UMR 7154

Résumé:

Ground-penetrating radar (GPR) studies conducted in iron-rich volcanoclastics can yield valuable information for interpreting the subsurface stratigraphy resulting from lava flows and intervening unconsolidated volcanic and sedimentary deposits with different compositions and ages. GPR is also valuable for mapping subsurface anomalies and structures, such as rifts and lava tubes. We performed a geophysical field survey in Craters of the Moon National Park to evaluate the potential for using GPR to map local areas of the Martian subsurface for evidence of subsurface water. Craters of the Moon is located in the South Central portion of Idaho, and lies within the Eastern Snake River Plain; it is a composite of more than forty different lava flows, erupted from approximately twenty-five cinder cones and eruptive fissures over eight distinct eruptive periods ranging in age from Late Pleistocene to Holocene. We used a GPR operating at 16 and 100 MHz to perform structural mapping at several different locations. Radar studies were combined with transient electromagnetic soundings and infrared spectroscopy to assess the effect of soil conductivity and geochemistry on identification of subsurface structures. Our results show that, even with a relatively high amount of irons oxides (~14 %), GPR penetration depths of 50 m were achieved with the 100 MHz antenna and penetration depths of 150 m were achieved with the 16 MHz antenna. These depths of investigation may be attributable to the high porosity of the soil at the studied areas, which lowered the electrical losses, thus favoring a relatively deep penetration of the radar wave.