A research project was undertaken in 1997 by participants in CRC-LEME which investigated the modes of development and the geochemistry of calcrete that is present in the weathering profile at Mount Gunson. Under the supervision of Dr Melvyn Lintern of the CSIRO, a number of vertical soil profiles were sampled, documented in detail and subsequently assayed. Two locations were studied: (1) the pit walls of the Cattlegrid open cut mine, where several vertical sections were sampled by abseiling over the lips of certain parts of those pits; and (2) shallow trenches that were excavated by backhoe adjacent to two drillholes at the Windabout deposit. These hoes had been previously core drilled from about 3 m below the surface, so the trenches needed to be dug to sample the uppermost 3 m of the regolith profile; drill core samples were used for logging the remainder of the sedimentary section. Because there is no extensive blanket of massive pedogenic calcrete existing at Mount Gunson, the study provided a useful comparison with the outcomes of studies done elsewhere where such massive calcrete is present in the regolith profile. At Mount Gunson, the most common form of carbonate development within the weathered profile is a calcareous loam, in which only fine flecks or hairlike seams of carbonate can be identified. Some minor, nodular calcrete is present within very thin skeletal soils, as coatings on bedrock fragments.