CARTER : GLACTATIOX OF DON AND DEARNE VALLEYS. 417 
In the railway cutting west of Conisbrough station Pro- 
fessor Green records* Coal Measures overlaid by sandy rain- 
wash, with rubble and large blocks of Magnesian Limestone 
and coal smut. At Conisbrough, near the station, boulder-clay 
was seen by Mr. H. H. Corbett in the foundations of some houses. 
At the Ashfield Brick Works, at the 22o-foot contour, 
there is a patch of drift containing Magnesian Limestone, 
Carboniferous Limestone, and Lake Country andesites. The 
deposit overlies Lower Permian Marls, which are much con- 
torted, and the Middle Coal Measures. On the opposite side of 
the Don gorge, at Cadeby, a similar deposit has been recorded 
by Messrs. Corbett and Culpin in a railway cutting, including 
boulders of andesite, Mountain Limestone and Magnesian Lime- 
stone. There is a general accordance in the facies of these 
Z'/J. Mills Hor icolc 4i Ve^t.o<iI 
Fig. 4. 
SECTION ACKOSS THE DON" «OR(iE AND THE BALBY BRICK PITS. 
M.L. = Magnesian Limestone. B. =Bunter. =Not exposed, Bunter 
inferred. B.C- — Boulder Clay. 
deposits, corresponding to the upper clay of Staincross, and 
linking it on to the remarkable boulder-clay deposit of Balby, 
near Doncaster, and the author proposes to explain them as 
the relics of the Stainmoor glacier, which he believes to have 
extended thus far at one stage of the Glacial Period. 
The Balby section is the most remarkable deposit of boulder- 
clay in the district (Plates LVL, LVIL, LVIIL). It forms an 
isolated patch about one mile long and half a mile wide, with 
its long axis running nearly east and west (Fig. 3). It is bounded 
on its northern side by Bunter sandstone, which also is found to 
underly it wherever the base is seen. The underlying surface of 
the Bunter is water-worn, and the junction is clean, without any 
intermediate warp or gravel (Plate LX., Fig. 1). The Bunter 
itself appears to fill up a pre-Triassic valley in the Magnesian 
* From his notebook, by kind permission of Mrs. Green. 
