Cosmic ray produced Be-10 and Al-26 in Antarctic rocks - Exposure and erosion history

• Main Authors: Nishiizumi, K., Kohl, C. P., Arnold, J. R., Klein, J., Fink, D.
• Format: Other/Unknown Material
• Language: unknown
• Published: 1991
• Subjects: 46; Antarctic; Antarc*; Antarctica
• Online Access: http://ntrs.nasa.gov/search.jsp?R=19910063326

Cosmic-ray produced Be-10 and Al-26 were measured in purified quartz fractions of selected rock samples from Antarctic mountains. From these data, mean erosion rates were calculated for the limiting case of steady-state surface exposure to cosmic rays, and minimum exposure ages, for the limiting case of no erosion. Calculated mean erosion rates are very low, on the order of a few times 0.00001 cm/yr; the sampling is believed to be sufficient to generalize this result to exposed bedrock in Antarctica. In favorable cases it is possible to distinguish between the limiting cases; steady-state erosion seems a better description in such cases. Most samaples, including some taken a few meters above the present ice level, seem to have been exposed for millions of years, without major episodes of burial or abrasion by ice.