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.
The southern margin of the Barberton Greenstone Belt in Eswatini limits one of the world’s oldest well-preserved sedimentary and volcanic sequences, 3.57 to 3.2 Ga old. In a segment along that margin, older mafic and ultramafic volcanic rocks were thrust over the youngest strata (quartz-rich sandstones and conglomerates) before being folded and imbricated in thrust slices. Samples described in this publication comprise tabular data of (1) sample locations and crystallization ages of zircons which were extracted from thin tuffaceous units in the thrust sheet, (2) analytical data from laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS), supporting these ages, and (3) quantitative measurements of ductily deformed conglomerate clasts. Field data were collected 2012-2019; U-Pb analyses performed in 2020. The data presented here are the basis for geological maps and cross sections, and are visualized as concordia diagrams form part of in the related publication (Heubeck et al.. 2023).