Reports & Proceedings—Geological Society of London. 383 
Dr. A. Strahan, F.R.S., exhibited cores from borings in Kent, 
showing pebbles of coal embedded in Coal-measure sandstones. 
With the coal-pebbles there occurred a few partly rounded fragments 
of chert, and in one of these Kadiolaria had been identified by Dr. G. J. 
Hinde. The chert resembled that which had been described from 
Lower Carboniferous rocks elsewhere. Its occurrence suggested that 
the sequence of strata had been similar in South Wales and Kent, 
and taken in connexion with the piping of the limestone surface at. 
Ebbsfleet and the absence of Millstone Grit in Kent tended to confirm 
the view that there is unconformity between the Coal-measures and 
the Carboniferous Limestone in that county. 
Mr. F. P. Mennell exhibited a geological sketch-map of the 
Northern Margin of Dartmoor. 
He said that the central part of Devonshire was to a large extent 
a terra incognita, but, as regarded the fringe of altered Carboniferous 
rocks along the northern border of the Dartmoor granite, he had been 
led, in the course of observations originally concerned with the 
petrology alone, to the conclusion that there was a probability of 
being able to establish a definite order of succession. ‘This was 
rendered possible by the occurrence of some well-characterized bands 
of rock, especially limestones and tuffs, which were exposed in every 
good river-section. It was true that almost everywhere overfolds, 
sometimes accompanied by thrusts, were to be detected, and tended 
to make the observer somewhat doubtful of his ground. Nevertheless, 
it seemed impossible to escape the conclusion that, as one approached 
the granite from the north, older and older rocks were met with, and 
the extremely continuous character of some of the beds seemed to 
show that, in spite of all minor disturbances, the general sequence 
could be trusted. The comparison of the different lines of section 
_ leading up to the moor showed them to be strikingly similar. The 
granite was, moreover, intruded all along at precisely the same 
horizon, and its direct offshoots never reached into the lower of the 
two important bands of limestone, but were confined to the altered 
shales at the bottom of the series, which afforded, where fresh, good 
examples of andalusite hornfels. The series, which extends from 
south of Sourton to Drewsteignton and perhaps right round to 
Doddiscombeleigh, appears clearly older than the shales which have 
been so carefully searched for fossils in the Exeter region by Mr. F. Q. 
Collins. These last are considered of Pendleside age, and nowhere 
contain any traces of limestone. The probability is thus indicated 
that the distinctly calcareous series under consideration may represent. 
part of the Carboniferous Limestone. 
It may be noted that, although there are a number of bands of 
epidiorite representing intrusions of dolerite roughly parallel to the 
strike of the sediments, the contemporaneous rocks are never of such 
basic character. The main band of tuff stretches from Lake, near 
Bridestowe, to beyond Sticklepath, and of the numerous well-preserved 
rock-fragments it contains, most are of rhyolitic or trachytic character, 
_ with some which represent altered andesites. __ 
_ The next meeting of the Society will be held after the long 
vacation, on Wednesday, November 8, at 5.30 p.m. 
