File:The Quarterly journal of the Geological Society of London (13889861498).jpg

AT GREAT CEOSBY, LANCASHIRE.
455
It was not until several examinations were made that I was able
to discover any striations on the imbedded sandstone. At last I
detected them on a block measuring 4 ft. x 2 ft. 10 in. x 1 ft. 9 in.
in extreme dimensions. On washing the marl.- clay off the face,
very good parallel groovings were disclosed, running along the plane
of bedding and the longer axis. With this clue I soon saw that
the undersides of most of the stones were polished smooth, and others
irreffularlv scratched.
Section at Moiuhrey Brich and Tile WorJcs, Great Croshy.
a, a. Grey shaly Keuper marl. h. Hard band in Keuper marl broken off at h\
b", b". Fragments of hard band, b, scattered through and imbedded in
the " kneaded-up " marl, c, c. " Kneaded-up " marl, that is the Keuper
marl or shale, worked-up into a grey clay, d, d. Blocks of sandstone,
some fine-grained and strong, others coarser in grain and often smoothed
and striated, in one instance strongly fluted, e. Half-imbedded block
/. Low-level Boulder-clay (marine), containing far-travelled erratics and
broken marine shells (brown in colour).
Specimens of the undisturbed marl and the kneaded-up marl
were sent to Mr. David Eobertson, F.G.S., who kindly examined
them microscopically. Xo organisms were found in either, and they
were practically of the same constitution. jSTo far-travelled erratics,
nor any stones or material that could not be referred to the Keuper
formation could be found in the kneaded-up marl. Even the half-
imbedded stones were, in all cases that I have seen, Keuper sand-
stones. The true erratics are confined to the overlying Low-level
Boulder-clay. This clay is so distinctive a deposit that it is only
necessary to say that here as elsewhere it contains fragments of
marine shells, and is undoubtedly of aqueous and marine origin.
Imjjortance of the Discovery. — The evidence of these disturbed
shales is of importance taken in connexion with the prevalence in
South-west Lancashire and Cheshire of glacial markings and
smoothed rocks.
At the present moment (March 1885) is to be seen a very fine
example of polished and striated rock at Flaybrick Hill, Birkenhead,
Cheshire, a veritable roche moutonnee which has only just been bared
of its covering of Low-level Boulder-clay.
It has, however, been a moot point with local geologists whether
these markings are due to land- or floating ice. I have myself
always considered that the weight of evidence preponderated in
favour of land-ice, though there are some facts apparently rrrecon-