38 
LAMPLUGH : GLACIAL SECTIONS. 
its position, nor composition, such as I should expect from a sub- 
glacial river ; nor from icebergs. It looks to me as if deposited 
in open water, of no great depth, with no ice excepting light floes. 
The question arises with regard to the hummocky nature of 
the clay on which the stratified band rests, whether this is due to 
erosion, or disturbance, or to unequal deposition ? Appearances 
generall}^ favour the latter, though there are signs of erosion also. 
I expect eventually to show that the band is on the same 
horizon as the the thick sands and gravels which separate the 
Purple Clay on the north side of the town, and I also believe that 
its southward continuation may be found in a similar band which 
may be traced almost continuously throughout the Holderness 
sections ; though before I can speak of this with certainty, it will 
be necessary to see that there is not more than one horizon for 
stratification in the Purple Clay. 
If finally proved to have so wide an extension, the stratified 
band will become of value as a dividing line in the clays, though 
there seems to be a growing tendency amongst giacialists since 
the breakdown of the evidence for a series of recurrent intergla- 
cial periods to avoid new lines, jast as naturalists now avoid new 
species, and to ' lump ' the deposits as much as possible. Yet I 
think that apart altogether from the theoretical aspect, lines such 
as these, in a confused and refractory mass like our boulder-clays, 
all deserve careful study, even though they be of no more intrin- 
sic value than the bedding' planes in a mass of limestone. To 
me, it does not seem necessary to 'lump' the whole of the sections 
because some present intricacies and difficulties ; and although 
the local variations which exist in the sections obscure and 
confuse them, and render a very close and careful study indis- 
pensable in many cases, — the oftener I examine them the more 
satisfied am I that wide-reaching' divisions other than those already 
made, exist both north and south of Flambro'. 
