and Freshwater Deposits of Eastern Not folk. STl 
to attribute the bendings, inclination, and dislocation of strata ; 
secondly, by landslips or the sliding down of sea-cliffs, or the 
falling in of undermined banks of rivers or of submarine 
sand banks; thirdly, by the stranding of islands and bergs of 
ice. It is possible that all these three causes of disturbance 
may have co-operated to produce the complicated movements 
which we now behold in the cliffs under consideration. 
By ordinary subterranean movement. — First, in regard to 
ordinary subterranean movements, a general subsidence must, 
I conceive, have taken place over a considerable area, in order 
to explain the submergence and burial of the trees of which 
the stools are found in situ ; and this forest bed could not 
have been brought up again, together with the incumbent 
drift, to the level of low water, without a subsequent upheaval 
nearly equal in amount to the previous subsidence. But 
such a depression and re-elevation of a large tract may have 
taken place slowly and insensibly, and without any derange- 
ment of the stratification. A question would still remain, 
whether such protuberances of chalk as those at Trimming- 
ham (p. 357), and the inclination or verticality of the asso- 
ciated drift, should be attributed to a local and violent move- 
ment from below, fracturing the chalk and thrusting up 
portions of it above the ordinary level of that formation. It 
is scarcely profitable to speculate on a subject which could 
only be set at rest if the section were prolonged downwards 
into the subjacent chalk. I have described in the Geol. 
Trans., vol. v., part 1, p. 213, masses of drift entangled in 
chalk at the top of the cliffs of Moen in Denmark; but in 
those lofty cliffs the section extends downwards for a depth 
of more than 400 feet into the underlying chalk with flints. 
The verticality of some of the layers of flint, the curvature of 
others, and numerous faults, bear testimony to such repeated 
convulsions, that I did not hesitate to refer the entanglement of 
the upper chalk and incumbent drift of Moen to subterranean 
movements. During those convulsions, fissures and chasms 
may have opened in the chalk, and masses of the superimposed 
boulder formation may have been engulfed. 
There are many sections, such as that represented in fig. 14, 
p. 368, where the first hypothesis which suggests itself is the 
protrusion upwards of a boss of chalk, which has forced the 
yielding and incumbent beds to fold round it, so that the beds 
become perfectly vertical on the flanks of the protuberant 
chalk. But it frequently happens that these masses repose on 
chalk and crag so horizontal and undisturbed, that we are 
entirely precluded from the supposition of a movement from 
below upwards. 
Fhil. Mag. S. 3. Vol. 16. No. 104. May 1840. 2 C 
