¹⁰Be and chemistry of impactites and target materials from the Rio Cuarto crater field, Argentina: Evidence for surficial cratering and melting

Abstract

We report in this study on the distribution of the cosmogenic isotope ¹⁰Be and major and trace elements in impactites (clast‐rich melt and glasses) and target materials (soil and loess) from the Rio Cuarto crater field in the Pampas of Argentina. The ¹⁰Be concentrations and chemical composition of the impactites are comparable to that of the soil and loess. These results are in agreement with an origin of the impact glasses by melting of a mixture of soil and loess, as also shown by comparison with experimentally fused loess samples. The ¹⁰Be concentration of the impactites indicates that the melting and the excavation did not penetrate beyond the soil and loess package. The high content of the trace elements Cr and Ni in the impact glasses compared to the target materials suggest incorporation of small amount (<1 %) of the chondritic impactor material.

Aldahan, A.A., Koeberl, C., Possnert, G. & Schultz, P., 1997: ¹⁰Be and chemistry of impactites and target materials from the Rio Cuarto crater field, Argentina: Evidence for surficial cratering and melting. GFF, Vol. 119 (Pt. 1, March), pp. 67–72. Stockholm. ISSN 1103–5897.

Keywords:

• Argentina
• ¹⁰Be
• chemistry
• impact crater
• impact glass
• sediment