FIFTY YEARS GEOLOGICAL RESEARCH IN THE BRISTOL DISTRICT. 53 
Mr. Richardson's chapter on the Neozoic rocks of Gloucester- 
shire and Somerset, published in 'Geology in the Field/ the 
Jubilee volume of the Geologists' Association (1910) gives a 
general account of these rocks. Allusion mav here be made to the 
corresponding chapter on the Palaeozoic rocks contributed by the 
present writer, and to the 'Sketch of the Geological History of 
the Bristol District' 1 by Prof. Lloyd Morgan and him (1909), 
which brings up to date Prof. Lloyd Morgan's account prepared for 
the British Association meeting at Bristol in 1898. 
There can be no doubt that the most important paper published 
during this period on local geology was that by Dr. Vaughan on 
'The Palaeontological Sequence of the Carboniferous Limestone 
of the Bristol Area' 2 (1905). If one may judge by the stimulus 
which this paper has afforded to research on the Carboniferous 
Limestone, and the wide applicability of its results not only 
throughout the British Isles but also on the Continent, no more 
important stratigraphical paper has been published since those by 
Prof. Lapworth on the correlation of the lower Palaeozoic rocks by 
means of graptolites. This paper has rendered the Avon Section 
the typical one with which all other Carboniferous Limestone 
sections in Western Europe are correlated, and leads year by year 
to the visit of geologists, singly or in parties, to study these ex- 
posures. This study was rendered easier by the publication in 
tqo6 in the Bristol Naturalists' Society's Proceedings of Dr. 
Vaughan 's paper on ' The Avonian of the Avon Gorge ' 8 illus- 
trated by a series of text figures of fossils, and by fifteen collotype 
plates of the cuttings and quarries on both sides of the river. 
Dr. Vaughan's work has been ably carried on and applied by Dr. 
(now Professor) T. F. Sibly in his papers on the Carboniferous 
Limestone of Burrington Combe 4 and of the Weston-super-Mare 
District 5 (1905) and of the Mendip Area 6 (1906). 
Other papers dealing with the local Carboniferous Limestone 
fossils are that by Dr. Vaughan ' On the Corals and Brachiopods 
from the Avon Section preserved in the Stoddart Collection ' 7 
(1903) and those by Mr. R. G. Carruthers on Carboniferous Corals 8 
(1908). 
The slight but interesting manifestations of volcanic activity 
in the Carboniferous Limestone rocks of North Somerset attracted 
a good deal of attention during this period. The first general 
account was given by Sir A. Geikie and Mr. A. Strahan 9 (1899) 
1 Proc. Bristol Nat. Soc, 4th ser., Vol. II, pp. 5-26. 
2 Q.J.G.S., Vol. LXI, pp. 181-307. 
:i Proc. Bristol Nat. Soc, 4th ser., Vol. I, pp. 74-168. 
4 Ibid. pp. 14-41. 
5 QJ.G.S., Vol. IyXI, pp. 548-563. 
6 Ibid. Vol. LXII, pp 324-380. 
7 Proc. Bristol Nat. Soc, n.s., Vol. X, pp. 90-134. 
8 Geol. Mag., n.s., Dec 5, Vol. V, pp. 20-31, 63-74, 158-171. 
9 Summary of Progress of Geol. Surv. for 1898, pp. 104-111. 
