Reviews—Howse on Glaciation in N. Britain. 269 
most portion, there is occasionally found a purer deposit of tenacious 
clay, containing fewer fragments of rock, but charged with numerous 
angular pieces of Chalk-flints. This clay does not appear to be more 
than five or six feet thick; and is supposed by Mr. Howse, from the 
Chalk-flints included in it, to be an extension of the great Scandi- 
navian Drift. 
Mr. Howse next proceeds to notice, under the designation of 
‘Raised Beaches,’ some beds of gravel, clay, and sand, with coal- 
drift, which are found on the flanks of some of the Magnesian Lime- 
stone hills, and on the top of the sea-cliffs between Sunderland and 
Hartlepool. These beds are principally composed of materials washed — 
out of the Boulder-clay, &c. and Magnesian Limestone, and contain 
fragments of Cyprina Islandica in some places, and the remains of 
land animals occasionally in others. Other superficial deposits are 
alluded to by the author. The whole he tabulates as follows 
(p. 170) :— 
‘1. Beds of peat, and submarine forests, with fossil remains of oak, alder, 
mountain-birch, and hazel, horns of Cervus alces and Cervus elaphus, 
Bos prinugenius, &c. 
. Rubble, transported from moraine-heaps of upper valleys. 
. Grayel-beds, forming remains of ancient raised beaches. 
. Sand, forming elevated mounds along the courses of valleys. 
. Brick-clay, with intercalations of laminated clay, sand, and peat-bed, 
containing skeleton of Megaceros Hibernicus and stems of Calluna 
vulgaris. 
6, Scandinavian drift (?), containing angular flints, and small fragments 
of rock, probably derived from the Boulder-clay. 
7. Boulder-clay, or drifted glacier-moraine, containing fragments of 
Cyprina Islandica. ; 
8. Ancient gravel-bed, resting on rock-surface.’ 
Ou Co bo 
Mr. Howse thinks that, at the period of glaciation of the rock- 
surface, most of the North of England was much higher above the 
sea than now—that the climate and physical conditions were similar 
to those which now obtain in Greenland and Spitzbergen—that 
glaciers filled all the present river-valleys—and that the whole of 
the surface of the land was more or less covered with snow and ice 
for nearly all the year. ‘The great depth of the Tyne Valley and its 
tributaries below the level of the sea, and the prevalence of gla- 
ciated rock-surfaces, are the grounds on which he bases these opinions. 
As to the origin of the Boulder-clay, the views of the author. are 
not quite so clearly expressed. ‘To quote his own words :— 
‘It therefore appeared certain, from these facts, that the moving ice, 
bearing these special boulders, which can be traced to their original beds up 
the Tyne, must have travelled from the west, from the higher ground to- 
wards the coast; and that the hypothesis of continental or land-ice, in- 
volving, as it did, the subsidence of nearly the whole island, and afterwards 
an immense change of climatal conditions to those at present existing, 
seemed more in accordance with the facts registered on these rocks, and 
absolutely necessary to explain the appearances of the glaciated surface, and 
the formation and deposition of the Boulder-clay, than the vague aud merely 
conjectural theory of the stranding of icebergs drifting southwards from 
some unknown northern locality.’ (p. 170.) 
