372 Reports and Proceedinys — Geological Society. 
Origin of Boulder-clay and the Sequence of Glacial Events.” By D. 
Mackintosh, Esq., F.G.S. 
In this paper the author minutely stated the results of repeated 
examinations of a number of new sections of drift-deposits, with a 
particular reference to the character of their bases and lines of 
jnnction between them. He described in detail the pattems ex- 
hibited by the grooved erratic stones of the skelly clays compared 
with irregularly scratched stones of the Lake District. He then 
gare a particular account of the character of the two skelly clays, 
and assigned reasons for believing in their tkreefold origin — the 
local grit and broken Shells accumulated by the sea, wkick at the 
time was fully charged with sub-glacial clay, and the erratic stones 
carried and dropped by floating coast-ice. He described phenomena 
proving that boulders must liave fallen into the clay, and called at- 
tention to the varying directions of strim on rock-surfaces (including 
some he had lately discovered), and their relations to the courses 
and cross-courses taken by erratic stones, some of which had travelled 
200 miles. He then connected the special observations he had lately 
made with the results of many years’ investigations extending around 
the basin of the Irish Sea, from Carlisle to Crewe, and from Crewe 
to Anglesey, and traced the horizontal and vertical extent of the 
three shelly drifts, and their relation to the mountain drifts of North 
Wales and the Lake District. He stated many reasons for rejecting 
the idea that land-ice had distributed either of the two Boulder-clays 
he had described, but left it an open question wkether the blue clay 
of North Wales, the Lake District, the Yorkshire valleys, and parts 
of Lancaskire, with its local stones, may not have been accumulated 
under land-ice. He concluded by stating that the paper was in- 
tended to be introductory to one on the correlation of the drifts of 
the nortk-west with those of the eastern and central parts of 
England. 
8. “ Discovery of Silurian Beds in Teesdale.” By W. Gunn, Esq., 
F.G.S., and C. T. Clough, Esq., B.A., F.G.S., of H.M. Geological 
Survey. 
The authors described the general physical characters of Teesdale, 
referriug especially to the position of the Burstreeford Dyke, the 
wliin, according to them, occupying a very different horizon at 
Forcegarth Hill and Cronkley Fell, so that the displacement indi- 
cated by it is probably 400 feet greater than bas been supposed. 
This disturbance has brougkt up the beds which lie at the base of 
the Carboniferous series in the dale, and these are exposed in the 
banks of the Tees at the old Pencil Mill at Cronkley, where they 
were formerly worked up into slate pencils. They are soft shales, 
usually gray or greenish gray, sometimes yellowish green or purplish 
red. They are very indistinctly bedded, but show traces of what 
mav be cleavage in some parts. From the character of the deposit, 
the" character of the dykes of the district, and the fact that these 
beds are not altered by them, the character of the veins traversiug 
them, and an apparent unconformity between these beds and the 
undoubtedly Carboniferous beds overlying them, the authors come 
to the conclusion that this deposit is not of Carboniferous, but of 
