Rev. W. Lower Carter — Glaciation of Don Valleys, etc. 547 



Barnsley, has recently traced two tongues of this drift into the valley 

 of the Dearne, and has recorded a section of contorted shale with 

 pockets of erratics from the excavation for the Barnsley gasometer. 



The Balby Boulder-clay covers an area of about five acres in 

 extent. It occupies part of a small valley in the Magnesian Lime- 

 stone, which previously was filled with Bunter Sandstone. In three 

 large pits a magnificent section of 40 feet of stiff till is shown 

 which has yielded many erratics, including a Shap granite (2 cwt.), 

 andesites and andesitic breccias, Eskdale granite, St. John's Vale 

 quartz-porphyry, Carboniferous Limestone, chert, Millstone Grit, etc. 

 The Bunter Sandstone on which this till is seen to rest has been 

 scooped out to form a clean, level floor, without any sand or gravel 

 intervening under the clay. In the excavations for the workhouse 

 a section of this till showed masses of Bunter sandstone torn off and 

 embedded in the till. 



About half-way along the arc joining Staincross and Balby is 

 another patch of Boulder-clay at Adwick-on-Dearne, containing 

 Carboniferous Sandstone, quartzite, felstone, and encrinital chert. 

 Close to this patch was found a third boulder of Shap granite 

 (15 cwt.). Contiguous to this zone are several patches of gravel 

 containing Carboniferous Sandstone with quartzite and chert, and 

 a boulder of ganister lies on the summit of Wombwell Hill. 



Beyond and to the south of this zone are several scattered patches 

 of drift. At Barbot Hall, about one mile north of Kotherham, is 

 a little hill covered with clay containing pebbles of quartz, sand- 

 ■stone. Carboniferous Limestone, and Oolitic rocks. At Masbrough 

 sand and gravel are found containing pebbles of Carboniferous 

 sandstone and quartz rock, and at Sitwell Vale, one and a quarter 

 mile south of Rotherham, is a clay with pebbles and boulders of 

 Carboniferous Sandstone. Near Hooton Roberts are three or four 

 patches of gravel containing Carboniferous Sandstone, with quartz, 

 quartzite, and black chert. 



At the western entrance of the gorge of the Don, at Conisborough, 

 a bed of Boulder-clay (about 15 feet thick) is shown at the Ashfield 

 Brick Works (225 feet above O.D,), including Lake Country andesites, 

 Carboniferous Limestone, a talcose schist with garnets, and other 

 rocks. About the same level, on the opposite side of the gorge, at 

 Cadeby, is a patch of drift with Carboniferous Limestone blocks. 

 Mr. H. H. Corbett, of Doncaster, has also kindly told me of a section 

 of Boulder-clay recently exposed in the valley between the railway 

 station and Conisborough Castle. At Sprotborough and Cusworth, 

 on the north side of the gorge of the Don, are patches of drifted 

 sand and pebbles, and from the fields have been ploughed up small 

 boulders of diorite, basalt. Mountain Limestone, ganister, and quartz- 

 porphyry. At Hexthorpe Flats, near Doncaster, striated Car- 

 boniferous Limestone with encrinites has been found, and between 

 Hexthorpe and Balby the ground is covered with drifted pebbles 

 and fragments of limestone. The Magnesian Limestone escarpment 

 ■south of Conisborough is strewed for some miles with patches of 

 drifted pebbles of quartz, sandstone, and Trias. 



