TIDDEMAN : GEOLOGY OF CLITHEROE AND PENDLE HILL. 179 
nature of their component rock and the excellent preserva- 
tion of the fossils to earth movements. ("On Limestone 
Knolls in the Craven District of Yorkshire and elsewhere," 
Quart. Jour. Geol. Soc, Vol. LV., p. 327.) 
Salt Hill is hardly a typical reef-knoll, but appears 
to be a spit or shoal, almost entirely composed of the 
dehris of crinoids. A similar deposit is to be seen near 
Cracoe in Craven. With this exception, the knolls between 
Clitheroe and Downham are fairly good specimens. 
(c.) The Shales -with -Limestones occupy the rising country 
between the knolls and the sharper rise of Pendle. 
Fossils, both animal and vegetable, occur in this series, 
but not so abundantly. The group has a thickness in 
places of 2,500 feet, and is composed of clayey and 
sometimes sandy shales, with impure clayey limestone, 
in many alternations of soft and harder beds. They are 
fairly well seen in Worston Brook above Worston. 
(d.) The Pendleside Limestone gives the first steep scarp, and 
shows a thick series of light-coloured, mostly brown, 
limestones, with many thin beds and interbedded shales. 
Chert beds abound in them. 
{e.) Not far above the Pendleside Limestone we come upon 
a second and often a third escarpment composed of the 
Pendleside Grit, mostly a fine hard sandstone with shale 
partings. The rock is in places exceedingly compact, 
almost like a gannister, but without the abundant 
vegetable forms so characteristic of the latter. Occasion- 
ally, but very rarely, this rock is a conglomerate with 
quartz pebbles. It retains glacial scratches well. 
{/.) The next feature is not a scarp but a hollow groove, 
evidencing soft rock. Such are the Lowland Shales, 
which, underlying the bolder Pendle Grit, give features 
and distinctive character to most of the principal ranges 
of hills in Craven south of the Craven Faults, and 
throughout the district of Bowland. This is very marked 
in the range of Pendle, which reaches from near Chorley 
