PROCEEDINGS 



OF 



THE GEOLOGICAL SOCIETY OF LONDON. 



1832-1833. No. 29. 



Dec. 19, 1832.— Richard Griffith Killaly, Esq., of Trinity College, 

 Dublin, was elected a Fellow of this Society. 



A paper was read, entitled " Report of a Survey of the Oolitic 

 Formations of Gloucestershire." By William Lonsdale, F.G.S. 



This survey was made in consequence of a resolution of the Coun- 

 cil, confirmed by the Annual General Meeting of 1832, that one 

 year's dividends of the Wollaston Fund should be applied to the 

 continuing, northwards from Bath, the survey of the oolitic formations 

 commenced by the author of the Report in the year 1827. 



The district examined is bounded on the west by the escarpment 

 of the oolitic hills from Toghill, A\ miles N.W. of Bath, to Meon 

 Hill, near Chipping Campden ; and on the east by the foot of the 

 coral-rag-hills, from the neighbourhood of Chippenham to Farring- 

 don, and thence by a straight line passing from Burford to Stow-on- 

 the-Wold and Shipston-on-Stour. The formations examined are the 

 marlstone, inferior oolite, Fuller's earth, great oolite, forest marble, 

 and cornbrash. 



The geologists to whose labours the author acknowledges himself 

 much indebted, are, Mr. Smith, Mr. Cumberland, Mr. Weaver, the 

 Rev. William Conybeare, Mr. De la Beche, Mr. Murchison, and 

 Mr. Greenough : he also notices the great advantage which he pos- 

 sessed in having the Ordnance Maps for the base of his survey. 



Marlstone. — This formation was originally established by Mr. Smith, 

 and its geological position, as a member of the lias formation, has 

 been subsequently proved by Mr. Phillips, in his valuable work on 

 Yorkshire. In Gloucestershire, the formation consists of about 150 

 feet of marl and sand, containing, towards the lower part, a bed of 

 calcareous or ferruginous sandstone, abounding with organic remains; 

 and its superior stratum consists of blue micaceous marl, the repre- 

 sentative of the alum shale of Yorkshire. The most characteristic 

 fossils are Gryphcea gigantea and Pecten cequivalvis. The marlstone 

 is co-extensive with the escarpment, and may be traced within it 

 wherever the beds subjacent to the inferior oolite have been denu- 

 dated. 



Inferior oolite. — In the South of Gloucestershire this formation con- 

 sists of nearly equal divisions of soft oolite and slightly calcareous 

 sand ; but in the northern portion of the county, the latter, for the 



