THE BEACON SANDSTONE AT B t . 
41 
Below the Hill I>\. 
From a position on the side of the hill B 1; we could see some miles away 
striking alternations of dark and light bands just peeping up from below the brown 
rock of a 15 . The dark bands are conspicuously paler than the overlying rock 
(dolerite) and are presumably carbonaceous sandstone. If we take this into con- 
sideration and the fact that carbonaceous sandstone is found in the Depot Nunatak 
moraine, and bands of it occur below B 1( it would seem that only the upper portions 
of the Beacon Sandstone are fossiliferous. 
The Beacon Sandstone at B x is locally disrupted by the dolerite, but the 
horizontal bedding is not materially disturbed, except at one place where huge 
masses of the sandstone have been bodily upraised. One of these dislocated masses is 
100 feet thick and a quarter of a mile long. It contains many small black iron-stained 
nodules (663), which are set in a matrix of very coarse quartz-grains. Of the 300 feet 
exposed near the camp, the major part is a pure, even- grained, coarse sandstone. 
False bedding or current-bedding is displayed, and locally there are discontinuous 
bands of quartz-pebbles (673, 674). The pebble-bands appear and disappear quite 
suddenly in the ordinary sandstone, and they are never more than four inches 
thick ; the pebbles themselves vary from the size of a sparrow’s egg to that of a 
hen’s egg, and quite 99 per cent, consist of vein-quartz or quartzite (672). Some- 
times the pebbles are very sparsely scattered, and a bed 12 feet thick may contain 
only a single pebble. The quartzite (quartz-schist) pebble (675) was found under 
such circumstances and measures 8x5x4 inches. The sandstone-blocks of Depot 
Nunatak display abundant lenticular pieces of yellow mudstone up to two inches in 
length, but these lenticles were not observed elsewhere. 
The carbonaceous matter (743-762) only occurs in the lowest hundred of the 300 
feet exposed ; the carbonaceous bands, like the pebble-bands, are there discontinuous, 
and often follow the intricacies of the current-bedding. The black bands commonly range 
from an eighth to a quarter of an inch in thickness ; some of them were found to extend 
horizontally for quite 100 yards, others disappear completely within a very few feet. 
Near this spot the sandstone is partially calcareous, and a blue limestone-band 
formed a conspicuous shelf projecting from the cliff-face. Just below this was a 
well-marked band of pebbles set in incoherent sand, or in sand only slightly 
cemented by carbonaceous matter. The following sequence, in order of superposition, 
will give some idea of the nature of the Beacon Sandstone at this spot. 
Top. (7) 200 feet — almost pure sandstone with occasional pebbles (GG5) 
(G) 2 feet — band containing carbonaceous substance (745-7G2) 
(5) 12 feet — sandstone with brown bands 
(4) 12 feet — hard white sandstone with a three-inch strip of fibrous 
mineral (wollastonite) (G76) 
(3) 12 feet — black shale and study sandstone (754) 
(2) G inches — limestone-band (G71) 
Bottom. (1) G feet — black shale (754) 
G 
VOL. I. 
