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2006 Annual Science Report

University of Hawaii, Manoa Reporting  |  JUL 2005 – JUN 2006

Terrestrial Analog Study: Sierra Madera Impact Structure, Texas

Project Summary

Sierra Madera impact crater is 12 km in diameter (Fig. 1) and is a well-exposed remnant of a complex impact crater, which contains impact-generated breccias (disrupted rock with sharp-angled fragments cemented in a fine matrix) and shatter cones (a cone-shaped fracture pattern found in rocks that have been exposed to a sudden release of energy, such as an impact) (Wilshire et al., 1972; Huson, 2006).

4 Institutions
3 Teams
0 Publications
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Field Sites

Project Progress

Sierra Madera impact crater is 12 km in diameter (Fig. 1) and is a well-exposed remnant of a complex impact crater, which contains impact-generated breccias (disrupted rock with sharp-angled fragments cemented in a fine matrix) and shatter cones (a cone-shaped fracture pattern found in rocks that have been exposed to a sudden release of energy, such as an impact) (Wilshire et al., 1972; Huson, 2006). Marine carbonates and lesser amounts of interbedded siliciclastic rocks were impacted, making Sierra Madera an ideal place to study the effects of shock metamorphism in carbonates and sedimentary rocks (Huson, 2006). Understanding how impact-induced shock affects the thermal infrared spectrum is very relevant to thermal infrared studies of Mars (e.g., Stockstill et al., 2005), where impact cratering has been an important process in re-working the surface materials (Strom et al., 1992).
Samples exhibiting impact deformation features were collected from the central peak area of Sierra Madera (Fig. 2), including monolithic breccias, mixed breccias and shatter cones. In addition, carbonate rocks were collected from one of the rim locations in order to compare carbonates that have experienced variable degrees of shock deformation and its effect on the thermal infrared spectrum. Thermal emissions spectra of these samples will be collected to evaluate the effect of impacts on the spectral absorptions seen in the thermal IR.

Huson, S. (2006) Field guide to the Sierra Madera Impact Structure, IFSG, 20 pp.

Stockstill, K., J. Moersch, S. Ruff, A. Baldridge, and J. Farmer (2005), TES Hyperspectral Analyses of Proposed Paleolake Basins on Mars: No Evidence for In-Place Carbonates, JGR-Planets, v. 110, 10.1029/2004JE002353.

Strom, R., S. Croft and N. Barlow (1992) The Martian Impact Cratering Record in Mars, H. Keiffer, B. Jakosky, C. Snyder and M. Mathews (eds.), The University of Arizona Press, Tucson, AZ, pp. 383-423.

Wilshire, H., T. Offield, K. Howard and D. Cummings (1972) Geology of the Sierra Madera Cryptoexplosion Structure, Pecos County, Texas, USGS Professional Paper no. 599-H, pp. 1-49.

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  • PROJECT INVESTIGATORS:
  • PROJECT MEMBERS:
    F. Scott Anderson
    Co-Investigator

    Victoria Hamilton
    Collaborator

  • RELATED OBJECTIVES:
    Objective 1.1
    Models of formation and evolution of habitable planets

    Objective 4.3
    Effects of extraterrestrial events upon the biosphere