28 Dr. D. Woolacott—The Interglaciul Problem. 
and South-West Scotland streaming across Western Northumberland 
was pressed south-eastwards over North Durham, and the Tees 
valley ice was diverted southwards. The northern ice that moved 
down the coastal region of South-Hast Northumberland and Hast 
Durham thus brought with it to these regions Scotch, Cheviot, Lake 
District, and Northumberland boulders, and to the Cleveland area 
all these together with Scandinavian rocks. 
(5) During the same epoch this coastal ice carried with it in its 
passage southwards shore and other deposits. These were pushed 
inland, and being reassorted by glacial streams were deposited in 
mounds! along the margin of the melting ice-sheet, the Grindon, 
Warden Law, and Sheraton Kaims of Kast Durham being formed. 
In his work on the glacier-lakes of Northumberland, Dr. Smythe 
has proved that the western ice from South-West Scotland and the 
Lake District was the first to retreat in this county,” and the evidence 
corroborates this in North-East Durham, as the Grindon and 
Warden Law® Kaims to the west of Sunderland * were formed on 
the free margin of the Tweed—Cheviot ice. Near Warden Law, 
cutting across the Permian escarpment, is a dry channel which 
may have been formed by the waters from the glacial streams that 
deposited this Kaim and the associated sands and gravels The 
country lying on the western boundary of this ice-sheet was 
free from ice in this region at that time. In the south of the 
county the shell-bearing Kaims at Sheraton were similarly formed 
on the free margin of the same ice-sheet,’ and the shell-bearing 
spreads of cemented sand and gravel in South-East Durham are also 
fluvio-glacial deposits formed under similar conditions.® 
(6) During the period of the maximum pressure of the combined 
ice-flows along the coastal region of North-East England the glacier- 
lakes of Cleveland were formed, the phenomena associated with 
which have been so fully described by Professor Kendall.’ These 
lakes lasted until the beginning of the retreat of the ice from the 
coastal region. 
(7) About the same time a system of ice-dammed lakes existed in 
1 Adopting the classification of fluvio-glacial mounds and ridges into Kaims, 
Eskers, and Osars proposed by Professor Gregory in a paper read before the 
Royal Society on April 29, 1920 (Gzox. Mac., June, 1920), those of Northumber- 
land and Durham are all Kaims. They were formed along the margin of the 
ice-sheet, some being deposited in glacier-lakes and others not. 
2 “ Glacial Geology of Northumberland ’’: op. jam cit., p. 104. 
3 Warden Law is 5 miles inland and 646 feet above sea-level. The gravels 
are 200 feet thick. Grindon is about the same distance inland. 
4“ Geology of N.E. Durham and S.E. Northumberland”: op. jam cit, 
. 102. 
a A list of shell-fragments collected in these Kaims by Trechmann is given in 
the Quart. Journ. Geol. Soc., vol. Ixxv, pt. iii, 1920, p. 194. They are 4 miles 
inland, and about 400 feet high. 
6 T have collected shell-fragments from the gravels at Dalton Piercy, near 
Hartlepool. 
7 Quart. Journ. Geol. Soc., vol. lviii, 1902, pp. 471-571. 
