Heterogeneous Dissemination of Projectile Materials in the Impact Melts from Wabar Crater, Saudi Arabia

Abstract

We confirmed the initial observations of Spencer (1933a,b) that two distinct impact melts coexist at the 90-m-diameter Wabar crater, Saudi Arabia A dark or "black" melt contains on the order of 4% meteoritic contamination, while the transparent or ''white" melt contains <1%. The Fe/Ni ratios in both varieties exhibit considerable scatter on electron-microprobe scales, akin to those reported by others for metal spherules in the black melt. If the meteoritic component is subtracted, both melts are chemically very similar. Clasts engulfed by the Wabar melts were investigated also, as they represent the progenitor lithologies from which the melts formed Bwk compositions for these clasts reveal subtle differences in modal feldspar content within the quartz-rich Wabar target.