Beginning in the south-east corner of the Gold Coast colony this range, composed of quartzites and schists, extends beyond the borders of Togoland into upper Dahomey.
The Falkland Islands consist entirely, so far as is known, of the older Palaeozoic rocks, Lower Devonian or Upper Silurian, slightly metamorphosed and a good deal crumpled and distorted, in the low grounds clay slate and soft sandstone, and on the ridges hardened sandstone passing into the conspicuous white quartzites.
The dark bituminous layers of clay slate, which occur intercalated among the quartzites, have led, here as elsewhere, to the hope of coming upon a seam of coal, but it is contrary to experience that coal of any value should be found in rocks of that age.
Many of the block mountains of the Great Basin are of complicated internal structure, showing rocks of all ages - slate, limestone, quartzites, granite, multi-coloured volcanic rocks, and large areas of lava overflow.
The quartz-schists consist of quartz and white mica, and are intimately related to quartzites.