682 PROCEEDINGS OF THE GEOLOGICAL society. [June 22, 
with mud from the grinding of the glacier on the infrajacent rocks— 
in fact, from the washings of the moraine profonde. This stream 
flows in a torrent the whole year round, and in every case which 
I know of (in the Arctic Regions) reaches the sea eventually, 
though, no doubt, parting on the way with some small amount of its 
suspended mud. After it reaches the sea it discolours the water for 
miles, finally depositing on the bottom a thick coating of impalpable 
powder. When this falls in the open sea it may be scattered over 
a considerable space; but when (as in most cases) it falls in nar- 
row long fjords, it collects at the bottom, shoaling up these inlets 
for several miles from their heads, until, in the course of time, the 
fjord gets wholly choked up, and the glacier seeks another outlet 
or gets choked up with bergs, which slowly plough their way through. 
the deep banks of clay, until they get so consolidated together as to 
shut off the land altogether’. Supposing that the deposit only 
reaches 3 inches in the year, there is a bank or flat 25 feet thick 
formed in the course of a century. However, any one who has seen 
these muddy sub-glacier streams, and the way in which they deposit 
their mud, must be convinced that this estimate is far below the 
mark, and that an important geological deposit, which has never 
been rightly accounted for (if even noticed, as far as my observation 
goes), is forming off the coast of Greenland and wherever its great 
glaciers protrude into the deep quiet fjords. It ought also to be 
noticed that the fjords which have been the scenes of old ice- 
streams, in almost every instance end in a valley at the head, this 
valley being due, first, to the glacier which reclined on it and hollowed 
it out, and, secondly and further down, to the filling up of it by the 
glacier-clay. This form of fjord is not only common in Greenland, 
but also in every other part of the world where I have studied their 
form and formation. 
After carefully examining and studying this clay, J can find no 
appreciable difference between it and the brick-clay, or fossiliferous 
Boulder-clay. Mr. Milne Home *, among other arguments against 
the theory that Boulder-clay has been formed by land-ice, remarks 
that he saw nothing forming in Switzerland at all comparable to 
Boulder-clay. Reserving to ourselves a doubt on that subject, I can 
only say that long after my opinion regarding the identical cha- 
racter of the subglacial-stream clay and the fossiliferous brick-clay 
was formed, a very illustrious Scandinavian Arctic explorer visited 
Edinburgh, and declared, as soon as he saw the sections of Boulder- 
clay exhibited near that city, that this was the very substance he 
saw forming in the Spitzbergen ice-fjords. Many theoretical 
writers, however, confound the ordinary non-stratified azoic clay, 
and the finer, stratified fossiliferous clay. 
Jn this clayey bed the Arctic Mollusca and other marine animals 
find a congenial home, and burrow into it in great numbers. How- 
? I am glad to find that, independently, this identical view is held by Mr. 
J. W. Tayler, who resided for several years in Greenland, Proc. Roy. Geogr. Soc. 
vol. y. p. 90 (1861). 
2 Trans. Roy. Soc. Edin. vol. xxv. p. 661. 
