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mals, as have been distinctly obtained from the marine crag, are more 
rolled than those found so abundantly in the mud cliffs. 
Drift. This important formation is strictly analogous in charac- 
ter with that which has been called in Denmark and Sweden the 
boulder formation, and which, from the numerous erratics included 
in it, presents so remarkable a feature in the superficial geology of 
Scandinavia, the countries surrounding the Baltic, and those ex- 
tending thence, uninterruptedly, to the borders of Holland, to re-ap- 
pear in Norfolk and Suffolk. Mr. Lyell believes, that the boulder- 
fragments in all these districts were accumulated on ground perma- 
nently submerged, and not by one or many transient rushes of water 
over land previously emerged ; and he therefore prefers using the 
term drift instead of that of diluvium, by which the deposit has been 
generally designated. The subdivisions of stratified and unstratified 
(till) materials exist in Scandinavia and Scotland as well as m 
Norfolk, and therefore indicate some peculiarity in their distinct 
mode of origin; yet in all these countries, as Mr. Lyell observes, 
part of the till was accumulated contemporaneously with the strati- 
fied drift, and both are often identical in composition; the distinc- 
tion consisting solely in the arrangement of the materials. The 
only recent deposits precisely similar in character known to the 
author, are the terminal moraines of glaciers; and he has no doubt, 
that similar accumulations must take place in those parts of every 
sea, where drift ice, charged with mud, sand and blocks, melts, and 
the earthy materials are allowed to fall tranquilly to the bottom. 
‘The occasional intercalation of stratified matter in the till, or the 
association of the two on a larger scale, he is of opmion, may be ex- 
plained by the temporary action of currents during the melting of 
the ice. The pebbles and erratic fragments of,larger dimensions found 
in the Norfolk drift, consist of granite, porphyry, greenstone, lias, 
chalk, &c. No fossils have yet been obtained in the drift from which 
the era of its formation can be inferred; and this absence of cha- 
racteristic organic remains, Mr. Lyell says, marks also the boulder 
formation in Scandinavia and Scotland. Near Upsala, however, he 
has seen large erratics resting on stratified beds corresponding in 
age to the till of that neighbourhood, in which numerous shells pe- 
culiar to the Baltic were imbedded ;—a fact which leads him to at- 
tribute, to some parts at least of the boulder formation of Scandi- 
navia, as recent an origin as can possibly be ascribed to the Norfolk | 
drift. 
At their commencement near Hasborough the cliffs are not more 
than twenty feet high, and are composed generally of blue clay co- 
vered with yellow sand, both, in some places, being stratified with 
great regularity. At some points where the stratified reposes on 
the unstratified, the surface of the latter is very uneven, and was 
evidently in that condition when the superior deposit was thrown 
down upon it. In 1829 the section at Hasborough was sand and 
loam thirteen feet—till, eight to sixteen feet—laminated sand and 
clay, partly bituminous, and inclosing compressed branches and 
leaves of trees, one and a half feet. ‘The cliffs between Has- 
