The Victoria River region, in the northwestern Northern Territory, is underlain by Precambrian rocks and flanked to the east, south, and west by Lower Cambrian volcanics and younger sedimentary rocks. The Precambrian rocks include a deformed belt of basement metamorphics, granites, and acid volcanics, all overlain by sandstone, in the northwest; and a stable platform (the Sturt Block) overlain by slightly deformed sedimentary rocks in the centre and southeast. The rocks in the deformed belt range in age from Archaean to Adelaidean (late Proterozoic). On the Sturt Block are several Proterozoic groups of sandstone, siltstone, and dolomite. The sequences developed are all shallow-water deposits, and are separated by several regional unconformities. They are overlain by late Adelaidean tillites and associated fluvioglacials. Only minor production of tin, gold, and barite has been recorded, and the major resource presently being exploited is groundwater.