( 68 ) [Jan., 



VII. THE FULLER'S-EARTH IN THE SOUTH-WEST 

 OF ENGLAND. 



By Ralph Tate, Assoc. Lin. Soc, F.G-.S., &c. 



In the early part of this year my honoured correspondent, M. 

 Terquem, of Metz, applied to me for information respecting our 

 Fuller's-Earth, as he was desirous to know the relations subsisting 

 between the formation as developed in the province of the Moselle 

 and in England. The account given of the Fuller's-Earth in our 

 geological manuals is very meagre, and could serve very little my 

 friend's purpose ; but fully aware that such description did not 

 embrace all that is known respecting the formation in this country, 

 I had compiled the summary that here follows: and in addition 

 supplemented our knowledge of the fossiliferous contents of the 

 terrain by the determination of a large suite of fossils in the collec- 

 tion of the Geological Society. These new materials render no 

 longer tenable the inferences that have been drawn on the affinity of 

 the fossils. 



The geological reader is aware of the great lithological and in 

 part palaeontological differences which exist in the Lower Oolitic 

 strata at the opposite extremities of their range in England. In 

 the belief that the present communication, brief though it be, is the 

 fullest exposition of the history of the Fuller's-Earth in the south- 

 west of England, I trust it will prove of service in future attempts 

 to correlate satisfactorily some one of the members of the Lower 

 Oolite of Yorkshire with that of the typical Fuller's-Earth. 



I may state in passing that the Fuller's-Earth in the department 

 of the Moselle has yielded more than 300 species of fossils, not in- 

 cluding microscopic forms, which number nearly one hundred ; M. 

 Terquem* has divided the formation into three zones of life — the 

 inferior characterized by Ammonites Niortensis ; the median, by 

 Ammonites Parkinsoni ; and the superior, hj Ammonites Baekerise. 

 No such divisions have been made out in the English beds. 



Extent and Thickness of the Fuller's-Earth in the South-west of 

 England. — With the other members of the Lower Oolite, the Fuller's- 

 Earth has more or less of uniformity as regards its constitution and 

 fossil contents from Dorsetshire to the borders of Oxfordshire. 

 Throughout this tract, it presents an argillaceous character with thin 

 beds of limestone and calcareous nodules. The underlying formation is, 

 in every instance, the Inferior Oolite ; but from the Dorsetshire coast 

 to near Hinton, on the borders of Somersetshire and Wiltshire, it is 

 overlain by the uppermost members of the Lower Oolitic series, and 

 to the north of that locality the Great Oolite appears, and throughout 

 the further extension of the Fuller's-Earth is the overlying formation. 



* In litteris. 



