404 W. D. Lang — Lower Plienshachian of Gharmouth. 



a crumbling, muddy condition, becoming pink-red on its surface. 

 A little Crinoid is common and characteristic of it; also a Nucula; 

 its commonest ammonites are those of the striatus group ; Trago- 

 phylloceras loscomhi (James Sowerby) and Deroceras davcei, (James 

 Sowerby) also occur ; as well as Nautilus and Gastropods. I have 

 not found the Ked Band in place on Black Ven, but fallen blocks 

 may be found above the Lower Limestone at the extreme eastern 

 outcrop of the Green Ammonite Beds on that clilf, showing that 

 it is just included there before the Lias is truncated by the 

 Gault. Some twenty yards west of where the blocks were found 

 there was a section ^ (now unfortunately foundered) showing the 

 junction of the Lias and Gault. The Lower Limestone was to be 

 seen in place some seven feet above the Belemnite Stone, six feet of 

 clay above the Lower Limestone, and then the junction before the 

 E,ed Band was readied. So the Bed Baud has a very short range on 

 Black Ven. On Stonebarrow Cliff it may be found west of Fairy 

 Dell,^ on the slope of broken ground above the precipice formed by 

 the Belemnite Marls, at some height above the 200 ft. contour-line, 

 and followed across the grassy places until, still before Pairy Dell is 

 reached, its outcrop is mostly on the cliff-face. Thence it runs 

 eastward under the more inaccessible parts of Fairy Dell, sometimes 

 on the clitf-face, but generally on broken ground above the clean 

 section. It is conspicuous just above the 100 ft. contour in 

 a semicircular section on the uudercliff between "Westhay Farm and 

 the sea, close to the ' y ' in ' Folly ' on the six-inch Ordnance Survey 

 map, and again immediately west of Westhay Water at 105 feet, and 

 may be seen at the head of the gully above the waterfall of that 

 stream. The red weathering of the top and bottom surfaces, in 

 contrast to the grey middle, is so marked in the Bed Band as seen 

 near Westhay Water that the Band appears from a distance to be 

 double, a condition it more nearly assumes further east, beyond the 

 liidge fault. Nearly a quarter of a mile east of Westhay Water is 

 the little waterfall known as Ridge Water, whicli is in the troiigh of 

 a syncline, since east of it the beds have a westerly dip. Rather less 

 than 300 yards east of Ridge Water, the cliff ends abruptly in a big 

 fault that lets the beds down about 100 feet^ on the east. Between 

 Ridge Water and this big fault are three little step-faults with a down- 

 throw on the east of from 10 to 20 feet. They do not, however, 



1 Described, Lang, Geol. Mag., Dec. V, Vol. I, pp. 125, 126, 1904. It was 

 visited by the Geologists' Association in 1906, see Proc. Geol. Assoc, vol. xix, 

 pt. ix, p. 323. 



* The great underchff on Stonebarrow, called ' Cain's Folly ' on the six-inch 

 Ordnance Survey map. I use the more familiar local name. 



^ The Survey, following Day (Quart. Journ. Geol. Soc, vol. xix, p. 282, 1863), 

 give a downthrow of only 40 feet (see H. B. Woodward, op. cit., 1911, p. 30) ; 

 but considering that at this point the Ked Band is reckoned at 45 feet above the 

 Belemnite Stone, it must be about 95 feet above the beach on the west side of 

 the fault, while it is beneath the beach 5 or 6 feet below the cliff-base on the 

 east side of the fault ; hence 100 feet is a fair minimum estimate of the dow;i- 

 throw. It is possible that there is a second fault a few yards further east, 

 sharing the 100 ft. downthrow with the obvious fault, but this has not yet 

 been definitely ascertained, and at any rate does not affect the present question. 



