The Peltabinna 1:75 000 Map Sheet was produced as part of a mapping program integrated into the Mineral Systems Drilling Program (MSDP) along the southern margin of the Gawler Ranges. The objective of the mapping program was to provide a regional geological context in which the stratigraphy, alteration and mineralisation of rocks revealed by the MSDP drilling could be interpreted, and comprised detailed basement, structural and regolith mapping. This report represents the Explanatory Notes to the Peltabinna Map Sheet, part of the Mineral Systems Drilling Program Special Map Series. Peltabinna is located at the south-western margin of the Gawler Ranges in South Australia. Palaeoproterozoic basement, covered by Cenozoic sediments, belongs to the Nuyts Domain of the Gawler Craton and includes variably deformed granitoids of the Peter Pan Supersuite, and the Tunkillia and St Peter suites. This basement is overlain to the north-east by the early Mesoproterozoic Gawler Range Volcanics (GRV) which on Peltabinna form a succession of extrusive felsic volcanics with minor intercalations of volcaniclastic rocks. The oldest GRV unit on Peltabinna is the Bittali Rhyolite which was emplaced as a lava. The overlying Eucarro Rhyolite, a composite lava flow, is subdivided into a black flow-banded base, a red-brown granophyric middle part, and an amygdaloidal upper part (Yannabie Rhyolite Member). The distinct quartz- and feldspar-phyric flow-banded Paney Rhyolite Member occurs in many places at the top of the Eucarro Rhyolite. The upper part of the Eucarro Rhyolite is locally overlain or intercalated with volcaniclastic-sedimentary rocks of the newly defined Mount Friday Formation. The overlying Yardea Dacite is subdivided into the Pondanna and Moonaree dacite members. Locally, these two lava flows are separated by the “Yartoo volcaniclastics”. Granites of the Hiltaba Suite were emplaced on Peltabinna shortly after ~1587 Ma as high level intrusions within both Palaeoproterozoic basement rocks and the overlying GRV. The MSDP drilling on Peltabinna identified epithermal alteration and mineralisation in GRV rocks within the Progress-Eurilla fault system. Drillhole MSDP05 intersected a ~200 m thick zone of alteration and quartz-pyrite veining, centred in the volcaniclastics-rich interval of intercalated Mount Friday Formation and Yannabie Rhyolite Member. This zone contains anomalous values of Ag, Pb, Cu, Mo, As, Bi, and Sb. Greisen alteration in Hiltaba Suite granite identified near Mount Friday is associated with low-grade Sn-Cu-Pb-Zn mineralisation. After emplacement of the GRV and Hiltaba Suite in the early Mesoproterozoic, the Peltabinna area was subject to weathering and erosion for a prolonged time period. Eocene to Pleistocene sediments were deposited in the Narlaby, Narlaby Plain and Progress palaeochannels, which form part of an extensive palaeodrainage system that developed along the north-eastern margin of the Eucla Basin. Quaternary colluvial, sheetwash, alluvial-fluvial and lacustrine sediments accumulated on the depositional plains surrounding the Gawler Ranges. Pleistocene to Holocene aeolian sediments, including the Moornaba Sand, constitute the main part of the Ilkina Dunefield around Mount Centre.