The bony plates are overlain by horny scales.
Large areas are overlain with trachyte, basalt, obsidian, tuff and pumice.
In the north the plateau is overlain by red and purple unfossiliferous sandstones, capped near its edge by a cherty limestone also unfossiliferous but possibly of Lower Cretaceous age.
This system rests unconformably on the Witwatersrand series and is unconformably overlain by the Transvaal system.
To 12 ft., under a covering of conglomerate locally known as lostra, which is itself overlain by a loose sandy soil.
They are often overlain by schists and quartzites, or broken through by volcanic masses.
At Hoopstad and at Stinkhoutboom the Witwatersrand series is unconformably overlain by 500 ft.
The lower and middle divisions of the Jurassic, composed of massive limestones more or less siliceous and overlain by the marls amd highly fossiliferous limestones of the Upper Lias, play an important part in the constitution of the chief mountains of the Tell.
The lower part of the Keweenawan system consists of a great succession of lava flows, of prodigious thickness.- This portion of the system is overlain by thick beds of sedimentary rock, mostly conglomerate and sandstone, derived from the igneous rocks beneath.
This series is overlain unconformably by a younger quartzite of similar character, and itself rests upon the crystalline schists.
From the edge of the coast belt to near the confluence of the Benue and Niger they are overlain by unfossiliferous sandstones, lying undisturbed and possibly of the age of the sandstones of the Congo basin.
They are conformably overlain by clays and limestones with Exogyra Overwegi belonging to the Lower Danian, and these by clays and white chalk with Ananchytes ovata of the Upper Danian.
The central plateau consists of ancient crystalline rocks with granites overlain by unfossiliferous sandstones and conglomerates considered to be of Palaeozoic age.
The basin in which these sandstones were laid down is limited on the east by ancient gneisses and schists overlain by the highly inclined red felspathic grits.
In the region of Adigrat the metamorphic rocks are invariably overlain by white and brown sandstones, unfossiliferous, and attaining a maximum thickness of moo feet.
They are overlain by the fossiliferous limestones of the Antalo group. Around Chelga and Adigrat coal-bearing beds occur, which Blanford suggests may be of the same age as the coalbearing strata of India.
These are overlain, perhaps unconformably, by a great thickness of lavas and volcanic breccias (Pniel volcanic series, Beer Vley and Zeekoe Baard amygdaloids), and these in turn by the quartzites, grits and shales of the Black Reef series.
From here they are absent up to the Gabun river, where they commence to form a narrow fringe as far as the Kunene river, though often overlain by recent deposits.