On a Glacial Conglomerate in the Table Mountain Sandstone. 239 
smaller ones, are well rounded; the small, often almost spherical, 
white quartz pebbles up to an inch in diameter, like those commonly 
found scattered through every part of the Table Mountain Sandstone, 
are particularly noticeable, and more abundant than any other sort. 
Nine pebbles showing signs of glaciation were collected. The largest 
is 34 inches in length, 2 in width, and about 1 inch thick. It is 
composed of a hard, gritty slate. One surface is almost flat and 
covered with scratches, which are chiefly in two series, crossing 
each other at an angle of about 3°; a few other scratches cut 
across both these sets; the opposite surface is also fairly well 
striated, but it has been worn down to a smaller extent. One of 
the edges of the stone is also scratched. This specimen is indeed a 
typical glaciated pebble. Five of the other pebbles are also charac- 
teristic specimens, but smaller in size, the smallest being only 
14 inches in length. The remaining three only show scratches on a 
portion of one surface. 
The evidence for a glacial origin of the conglomerate, 1.¢., that ice 
played an important part in the locality during its formation, rests 
upon two facts :— 
(1) The peculiar character of much of the rock itself, viz., the 
distribution of large pebbles at intervals through a fine-grained 
sandy mudstone. 
(2) The flattened and facetted form of the pebbles, and their 
striated surfaces. 
In ordinary conglomerates the pebbles are very much more 
mumerous in proportion to the matrix than in the Pakhuis beds, 
and at the same time they are arranged in layers; generally, too, 
there is a rough assortment of the stones, so that pebbles of about 
the same size are found together. The Pakhuis rock is best com- 
pared to glacial deposits, such as the Dwyka conglomerate of this 
country or some of the tills of the northern hemisphere. 
In the absence of any observed unconformity at the base or top 
of the Pakhuis beds they may have been deposited in water, like the 
sandstones above and below; the shaley portions certainly were, and 
as unstratified sandy clays with ice-born fragments are admitted to 
have been formed under water in recent times, there is no sufficient 
reason to assume terrestrial conditions in the locality during the 
formation of the unbedded part of the Pakhuis conglomerate.* 
When the conglomerate was first observed its points of resemblance 
to the Dwyka conglomerate immediately attracted attention. The 
similarity consists in the scattered striated pebbles being embedded 
* Feilden, ‘‘ Glacial Geology of Arctic Europe,” &c., Q.J.G.S., vol. 1., 1896, 
p. 739. 
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