2D grain size data of sandstones from the 3.2 Ga old Moodies Group, Barberton Greenstone Belt (South Africa)

The Moodies Group (ca. 3.22-3.21 Ga) of the Barberton Greenstone Belt (BGB), South Africa, is the uppermost and youngest unit of the BGB, the largest and best-preserved Greenstone belt in the basement of the Kaapvaal Craton. It consists predominantly of fine- to coarse-grained, composi-tionally immature to mature, quartzose sandstones up to 3.6 km thick, with significant units of con-glomerates and siltstones and minor volcanic rocks and ferruginous sediments. The quartz-dominated Moodies sandstones mark long-term, large-scale access of surface systems to crust-stabilizing, high-level granitoid igneous rocks. 47 petrographic thin sections of sandstones from these sandstone units were analyzed for 2D grain size analyses. At least 500 measurements of long axes per thin were taken, using a Keyence VHX-6000 digital microscope. Samples which show significant grain boundary migration and subgrain rotation were excluded from this analysis (Passchier and Trouw, 2005). The data are presented as single ASCII file (tab-delimited text). The file 2022-023_Reimann-et-al_2D-grain-size-data.txt contains measurements of grains long axes from thin sections.