Fossil Plants from the Nubian Sandstone of Eastern Darfur

Abstract

The plant-remains described here, and now deposited in the Department of Geology, British Museum (Natural History), were collected in 1924 by Mr. G. V. Colchester, Assistant Geologist to the Sudân Government, to whom I am indebted for the opportunity of examining them, and for the following particulars of their occurrence. The fossils were found at Jebel Dirra, about 75 kilometres (47 miles) east of El Fasher. Jebel Dirra rises about 300 feet above a plain of Archæan rocks, and itself has a granitic core, with soft mica-schists on the northern face. It is capped by horizontally bedded sandstones, fractured blocks of which cover the south-western face of the hill. The plant-remains, which are very fragmentary, were collected partly in situ at the summit and partly from the loose weathered blocks just mentioned; they occur in a highly silicified quartzitic sandstone, and are the first fossils to be found in Darfur in the Nubian Sandstone. Although only two species have been definitely recognized, they afford strong evidence for assigning these beds to the Lower Cretaceous System, or possibly to the base of the Upper Cretaceous, and their discovery is, therefore, of considerable importance. One or two blocks contain fragmentary invertebrate fossils, which appear to be quite indeterminable. Some small fragments of this plant are sufficiently well preserved to show the rounded pinnules, about 6 mm. in length, attached by the whole base, with a thick lamina and anastomosing venation (fig. 1, p. 95). Other fragments, not showing the venation quite so