Having confirmed the eclectic nature and presence of eolian additions in a classical lateritic regolith in Australia, we request renewal of this funding for continued study off continental weathering systems. We seek to make more new applications of unique microbeam capabilities of the SHRIMP (sensitive high-resolution ion microprobe) to surface process studies centering on the provenance, surficial transport and in situ weathering behavior of zircon, a chemically resistant and datable pathfinder mineral of unparalleled utility. We wish to define ancient eolian dispersal patterns and mineralogical gradients of dust-size weathering product and insoluble detrital accessory minerals across the tectonically-stable Yilgarn craton of Western Australia. Our study will focus on sampling a sequence of uneroded laterites in an easterly transect leading away from the principal source region which we infer to have contributed foreign zircon to the Jarrahdale bauxite near Perth Australia by paleo-eolian processes. In the 700 Ma Leeuwin Block of the Pinjarra Orogen source region, we wish to study the accessory mineral suite (zircon, rutile, monazite and ilmenite) in bedrock granite, granulite and anorthosite exposures and date the zircons. Also, by dating eolian zircons in contemporary dust samples collected from rain gauge arrays, we can ascertain if source regions have shifted significantly. Finally, we wish to study the mineralogical and isotopic processes of in situ weathering of parent material zircon and to pursue direct SHRIMP dating of authigenic anatase. We wish to test their use in characterizing and timing the advance of the weathering front and biomechanical admixing rate of detritus into the subsurface thereby augmenting the array of geochronological methods available for surficial process studies.
