NASA Astrobiology Institute (NAI)

During the 2007 field season at the Flashline Mars Arctic Research Station (FMARS) at Haughton Crater on Devon Island, Nunavut, Canada, we collected pale grey impactites (rocks affected by the meteor impact) at the Lake Trinity and Gemini Hills sites. These impactites contain clasts, pieces of the target rocks hit by the meteor. This work is relevant to astrobiology in that it could lead to a greater understanding of impacts with carbonate targets, and contribute to the debate on ALH 84001, the famous Martian meteorite.

During the 2007 field season at the Flashline Mars Arctic Research Station (FMARS) at Haughton Crater on Devon Island, Nunavut, Canada, we collected pale grey crater-fill impactites at the Lake Trinity and Gemini Hills sites (see Figure 1). At each site, we determined the modal composition of cm-to-dm-sized clasts, documenting the number of clasts of each lithology (limestone, dolomite, sandstone, shale, gneiss, igneous). We also took representative samples for laboratory analysis.

Osinski et al. have extensively surveyed the Haughton impact structure and found what appear to be melted carbonates, based on the textures and compositions of target rock samples collected at the crater. This is controversial, since it had previously been assumed that impacted carbonates decompose and devolatilize rather than melt.

We are currently analyzing the FMARS samples in thin section using a scanning electron microscope, and expect to produce a paper based on the results.