46 
DESCRIPTION OF THE ROCKS 
30 , 31 , with the Hawes section p. 38 , will prove in addition that the 
development of these grits, and shales, and coal, is proportioned to that 
of the Cam limestone, so that the deposition of both groups may be re- 
ferred to the same agencies. The geographical origin of these agencies 
may be satisfactorily inferred from the local amount of their effects ; the 
nature of the agencies is indicated by the mineral nature of the deposits ; 
and from the whole combined we may believe that the line through 
Jervaux abbey, Kettlewell, Ryeloaf, and Lancaster, divides the oceanic 
from the littoral portion of the great mountain limestone deposits. 
Parting from below Great Whernside, as a centre, we find that 
along the whole length of Coverdale, stretching fifteen miles to the 
north-east, parallel to the coast line, the thickness of plates and grits 
above the middle lime, augments from eighty to only one hundred 
and fifty feet ; — in an easterly direction it is diminished to thirty, and 
in a southerly and south-easterly direction appears to vanish altogether. 
In like manner all the flagstones and plates under the middle lime- 
stone, in Great Whernside, are included in a space of one hundred 
and fifty feet : this space augments on the north by east to four hun- 
dred and eighty feet, on the north-west (Hawes) or proceeding directly 
toward the ancient shore, to seven hundred and eighty feet, on the west 
(Penyghent) to three hundred feet ; but on the east, south-east, and 
south proceeding toward the deep sea, it is reduced to nothing. 
The influence of land inundations, and littoral movements is greatest 
toward the north-west, where the slate ranges of Cumbria had been 
uplifted ; the purely oceanic character of the limestones is greatest toward 
the south-east, where land was in that asra very distant. 
South-Western Districts of the Yoredale Series. — Proceeding to 
the S. W. for the purpose of connecting the general base of the 
series, in Wensleydale, with that in Ribblesdale, and passing over 
the intermediate mountains by Weather fell, (or Bear fell), Dod fell, 
and Cam fell, we obtain the following results. The surface of the 
lower limestones rises from Wensleydale to Kibble head, nearly two 
hundred feet; the Yoredale series is about one thousand feet thick; in 
