The Granite Area of the Schapenberg, Somerset West. 195 
been intruded. Unfortunately exposures, in places where one would expect 
the rocks to be least alTected by the intrusion of the granite mass, are 
comparatively rare, and, almost invariably, they are much weathered. These 
rocks form the gently sloping ground to the south-west of the Schapenberg, 
which, when soil-covered, is generally under cultivation ; uncultivated areas 
are, as a rule, found to be covered with gravel the fragments of which are 
dark brown, ferruginous grits.* 
Several pits have been dug in this deposit at various places alongside 
the main road to Caledon which show that it attains a thickness of several 
feet. Along the top side of this road, between Somerset West and Water 
Kloof, there are two or three exposures — much weathered — of Malmesbury 
beds in situ. The rocks have a light yellowish -brown colour, dip almost 
vertically, and strike N.N.W.-S.S.E. They appear to be fine-grained, 
argillaceous grits. 
Although rocks of this series form the north-eastern portion of the 
Schapenberg (comprising the farm Harmonie and small portions of Altona 
and Myrtle Grove), exposures of them m situ are hard to find. Along the 
junction of this series with the granite in this locality, and particularly 
that portion of it which is in Morgen Ster, isolated blocks— most probably 
in situ — were found ; some are of hard blue-grey grit, resembling hornfels ; 
others, presumably varieties richer in argillaceous material, are spotted and 
occasionally micaceous, and always much weathered ; whilst others again 
are highly tourmalinised. Veins composed of quartz and tourmaline — the 
two frequently occurring in parallel bands— traverse the beds in this 
locality. One specimen of a grit breccia was found lying loose on the 
surface. Fuller descriptions of such of these rocks as were suitably fresh 
for the preparation from them of thin sections, are given below. 
Mention has already been made of the hill in Morgen Ster, isolated from 
the granite mass. Here the beds are well exposed. The rocks appear to be 
extremely fine-grained, indurated grits. Towards the top of the hill they 
are very massive. Whereas the strike is very generally W.N.W.-S.S.E., the 
dip varies both in direction and amount. On the western side of the hill 
the beds appear to be almost vertical, whilst to the north and west they 
dip about 70° E.N.E. and W.S.W. respectively. Apparently the beds 
forming the hill are striking along an anticlinal axis of folding. On the 
eastern side of the hill, in the ravine, the junction with the granite occurs, 
* Several views are held as to the meaning of the term grit. Harker's use of the 
term is for a sandstone in which the component grains are angular. Hatch and 
E-astall's nomenclature is based on the size of the grains — irrespective of their shape ; 
they regard rocks in which the grains have diameters greater than 2 5 mm. as a grit. 
Greikie uses the term for a very coarse-grained sandstone ; Judd for a coarse-grained, 
felspathic sandstone, in which the component grains are angular. In this paper 
Harker's use of the term has been adopted. 
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