HOORC researchers and associates have published Origins and palaeo-environments of Kalahari duricrusts in the Moshaweng dry valleys (Botswana) as detected by major and trace element composition in a recent issue of the Journal of African Earth Sciences. A.B. Kampunzu, S. Ringrose, P. Huntsman-Mapila, C. Harris, B.W. Vink, and W. Matheson carried out geochemical analyses of duricrusts -- surface or near-surface hard layers -- from the margins of the Moshaweng dry valleys to provide a diagnostic basis for paleoenvironmental conditions and to help stimulate development of a worldwide duricrusts database to complement existing databases on geochemical composition of sedimentary rocks. You can find the article in HOORC's Library.