File:The Quarterly journal of the Geological Society of London (13204538905).jpg

100
T. M. EEADE ON THE DEIET-BEDS OF THE
differ more or less from time to time.
In December 1872 I made sections at
several points (figs. 16-19). There
are in the Boulder-clay sand and
gravel seams more or less persistent,
sometimes two, occasionally a third,
and sometimes only one, or, it may be,
a seam of finely laminated clay, the clay
a,bove the sand seams or seam having
blue facings. The lower part of the
clay below these seams is largely
mixed with red sand, and appears to
contain a much larger percentage of
rolled boulders or pebbles than the
uppar.
The base of the Boulder-clay in
other localities is often distinguished
by these two features (see section at
Bootle-Lane station, Part L, Quart.
Journ. Geol. Soc. vol. xxx. p. 28).
The base of the Boulder-clay is
nowhere to be seen on the east mar-
gin of the Dee.
There are a great many very large
erratics on the shore near Dawpool ;
these have been already pretty fully
described by Mr. Mackintosh.
In May 1873 I examined with Mr.
Shone the excavations of the West
Cheshire Lines Railway near to Ches-
ter. This section showed a large de-
velopment of sand, to some extent
stratified, capped mostly, but not in-
variably, with a bed of fine purple
Boulder- clay containing but few
stones. In some places the junction
between the sand and the clay formed
a very irregular line. A section of
this cutting is given in Mr. Shone's
paper, Quart. Journ. Geol. Soc. vol.
xxxiv. p. 384. The sand occasionally
contained thin beds of clayey sand ;
at one point the junction of the sand
and clay was nearly vertical. The
sand, to all appearance, contained
neither boulders nor gravel.
River Alyn. — This river is a tri-
butary of the Dee. In the right
bank towards Eossett, forming a
spit of land between the valley of
•? ft"*
Hd
£
§