1Raining lead around 250mya: a smoking gun for an Australian impact origin of the Permian Extinction. (2170 words)

• Main Authors: Jim St, C. Austen Angell
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.554.3333; http://www.public.asu.edu/~caangell/426.pdf

Recent documentation of extreme atmosheric sulfur and methane coincident with the vast Permo-Triassic (P-T) extinction allows interpretation of a 40-year old report of metallic lead microspheres, with aerodynamic tails, in the graphite-loaded fluvial strata of early Triassic sandstones in the Sydney basin. While climate change and flood basalt volcanism could explain the atmospheric anomalies, only an extraterrestrial impact in a lead sulfide mineralized zone could explain the occurrence of native lead in this form. Using thermodynamic arguments, flow directional data for the sandstones, and Tasmanian mineralization data for the lead origin, we deduce an impact site in Bass Strait, where ring-like gravitational anomalies, and a provocative "interior basin " structure complete with melt-rocks at 2 km depth (as in the Cretaceous-Tertiary (K-T) boundary Chixculub crater) are found in gravity survey and oil drilling maps/reports. We predict the co-occurrence of lead tears and graphite elsewhere, possibly in Antarctic sandstones. Since the impact origin of the K-T boundary extinction [1] was established