68 
CLARK: ON THE TKIASSIC BOULDER, &c. 
About one quarter of a mile westwards, 200 yards or so 
beyond the first bridge west of the station, we found a most 
interesting cutting, almost entirely in the gravels, which 
practically determined the age of the rocks. The upper ten 
feet had been removed for a breadth of over 100 feet. Below 
this the cutting had been made to the right level, and about 
18 feet broad, with vertical sides. At the beginning a branch 
cutting, 26 feet deep, exposed a double fault, where sands 
abutted on either side against pebbles, containing a horizon- 
tal wedge of sand, apparently from an inferior bed (PL IV., 
Fig. 1). This was implied, not only by the relative positions, 
as regards the general rule of upthrow and downthrow, but 
by the condition of the two beds; the thicker, although firmly 
cemented, not being so hard as the tongue against which 
they rested. This was like hard Bunter Sandstone, being 
24 feet in length and 6 feet thick at the east end. 
Apparently unconnected with these, and about 50 yards 
along the main cutting, a remarkable series of faults, bringing 
down what may have been the same sandbeds, was well ex- 
posed on both the north and south walls of the cutting, to a 
depth of 17 feet, or 27 feet below the surface (PI. IV., Fig. 2). 
Our attention was first attracted by a mass of sand, let down 
by two faults on the south side, one striking 10° W. of N., the 
eastern one 42° E. of N., their dips, respectively, being 55° 
and 70° along the face, or about 82° and 54° in true dip. The 
south section was 8 feet wide, the faults meeting 9 feet down; 
but on the north side the sand was 27 feet wide above, and 
more than 9 feet below. The consistency was equal to that 
of the masses in the side cutting, so that we could stand and 
look over the sharp edge. One or both of two thin sand- 
beds, resembling the wedge in Fig. 2, exposed at the east end 
of the south section, revealed four or five minor faults, at the 
same inclination as the eastern one, and probably coinciding 
in strike. But this was uncertain, as no sandbeds made 
them apparent on the north side, and although there were 
