DESCRIPTION OF THE COAST. 
41 
was at first much disposed to think this a portion of a tertiary stratum, 
and still am altogether at a loss to explain the appearance of so enormous 
a mass of perishable clay, having the appearance of lias at such a dis- 
tance from the nearest cliffs of that stratum. I recommend this point 
for further observation. The specimens of pholas crispata washed ashore 
full of coherent sand, prove nothing whatever on this subject : such dead 
shells are particularly liable to be filled with the matter on the bed of 
the sea; and the only remarkable circumstance in these specimens is 
that the matter which they contain is unusually solidified. Excepting 
those imperfect indications, I have never heard of a single fact which 
would authorise a belief that tertiary strata exist in Yorkshire. 
RISE OF THE CHALK. 
No contrast can be more decided than appears between the solid, 
regular, continuous strata which have been formed by the repeated ope- 
rations of a primeval ocean, and the mixed and irregular aggregations 
which mark the force and direction of subsequent diluvial currents on 
the surface of the earth. From Bridlington pier we look southward to 
a long line of wasting cliffs formed of detritus swept from the distant 
regions of the west and north-west, and our imagination is tasked to 
frame conjectures on the state of the land during and previous to all 
that violence of water ; — whilst northward rise strata of chalk which, 
if compared to some other formations, must be called of recent date, yet 
were certainly deposited and hardened, and, in many places covered by 
several other rocks long before any considerable part of the surface of 
the earth, in these regions at least, was elevated above the sea. The 
considerations which belong to the two classes of phenomena are, in 
several respects, wholly different, and many geologists of good attain- 
ments have been content to study only one of them. The superficial 
deposits must, however, be both closely examined and viewed on a 
general scale, if we desire really to unveil the natural history of the 
earth. For such inquiries Holderness affords one of the best examples 
in the British isles. 
G 
