182 TIDDEMAN : GEOLOGY OF CLITHEROE AND PENDLE HILL. 
Lower down the slope you come to the First Grit or Rough 
Rock, a soft, coarse, pebbly conglomerate, and beneath it in places 
a coal, and then Haslingden flags, thinly bedded, rippled flags. 
Other flags of better quality lie above the Rough Rock. 
Then the Lower Coal Measures come on and show in places 
marine fossils. The Arley Mine is taken as the base of the 
Middle Coal Measures, and is one of the best seams of the Coal- 
field, but the coals are not within the limit of a day's excursion, 
and are moreover much c^overed with Drift. 
Drifts. Those who wish to see drifts might study the long 
gravel mound or esker which runs from A^'addington to Bashall, 
and takes up its course again on the far side of the Hodder, 
three-quarters of a mile north of Stoneyhurst. 
Whitewell (nine miles) is well worth a day's excursion from 
Clitheroe, or a week-end stay. The scenery is beautiful, and the 
Geology distinctly good. The reef knolls may be studied, and 
fossils knocked out in abundance, and there are good sections of 
the beds above the limestone. The north-west side of the Hodder 
will be found best to work at, but a trip from Whitewell Hotel 
to the Trough of Rowland, on the mountain pass to Lancaster, 
may be strongly recommended. 
