Sedimentary rock at Gusev?
The rock in the lower right corner looks similar to the rocks at the Opportunity site:
Or perhaps it could be jsut pumice:
Pumice
http://volcanoes.usgs.gov/Products/Pglossary/pumice.html
Bob Clark
The rock in the lower right corner looks similar to the rocks at the Opportunity site:
Or perhaps it could be jsut pumice:
Pumice
http://volcanoes.usgs.gov/Products/Pglossary/pumice.html
Bob Clark