﻿1861.] 



KIRKBY PERMIAN, SOUTH YORKSHIRE. 



293 



Rothliegendcs is a series of limestones of various characters which 

 may be conveniently grouped as the Lower Limestone. Some of these 

 are oolitic, pisolitic, and nodulous (Brodsworth, Moorhouse, &c.) ; 

 other beds may be termed polyzoan, being almost solely composed of 

 fragments of Polyzoa (Brodsworth, Cadeby, &c.) ; others are cellular 

 and unstratified (Pontefract); and others, again, are compact (Hickle- 

 ton, Conisborough, &c), or arenaceous (Bag Hill, Pontefract, Barn- 

 borough Cliff). Perhaps there is no single section of the Lower Lime- 

 stone that shows the whole of these beds, though by examining a 

 mile or two of the escarpment, or a few transverse sections of the 

 limestone west of the Small-grained Dolomite, limestones of all the 

 characters mentioned may be met with, besides others that are more 

 or less modifications of these. In the vicinity of the Don the upper 

 portion of this subdivision is a soft, thick-bedded, yellowish, oolitic 

 limestone, — the roe-like grains being in some beds intermixed with 

 irregularly rounded concretions as large as peas, and in others with 

 concretionary nodides an inch or more in length, it being not un- 

 common to find the same stratum oolitic, pisolitic, and nodulous. 

 Several species of fossils occur in these beds, generally as casts. A 

 little lower down are some thick beds equally as soft as the former, 

 which are chiefly composed of comminuted Polyzoa, principally of 

 the species Acanthoclaclia anceps. Beneath these and immediately 

 above the sandstone are other beds, which are thinner, darker- 

 coloured, and more compact, or rarely earthy. Numerous remains 

 of a few species of fossils occur in these beds, but often most imper- 

 fectly preserved *. 



In other places more to the north, especially about Pontefract and 

 at Wentbridge, the upper part of this subdivision is soft, yellowish, 

 amorphous, and full of irregularly shaped sparry cavities. Under it 

 are some thick beds of a harder limestone in which are immense 

 quantities of Gervillice (casts). Below these are some thin strata of 

 hard, compact, pisolitic, and arenaceous limestones, charged with 

 the remains of Aoc'mus dubius and GerviUia antiqua. These latter 

 beds are seen to rest upon the Bothliegendes at Bag Hill, opposite to 

 Pomfret Castle, where they become arenaceous and almost graduate 

 into sandstone. 



The junction of the lower beds of limestone with the Eothliegendes 

 can be seen to great advantage in several sections in and about Pon- 

 tefract, as Prof. Sedgwick has pointed out. It can be well studied 

 in section to the south-west of the town in some road-cuttings and 

 quarries, particularly in one on the Carlton and Ackworth road. 

 Another interesting section is to be seen in an obscure old quarry on 

 the escarpment, just above the pretty little hamlet of Carlton, where 

 the lowest limestone, which is cellular, void of stratification, and 

 charged with a few badly preserved fossils, rests upon an irregular 

 surface of the sandstone, the latter being yellowish, moderately hard, 

 and false-bedded. The lowest limestone in this instance appears to 



- Prof. Sedgwick describes the most characteristic of these beds in section ix. 

 of Ms "Great Middle Deposit of Yellow Magnesian Limestone." Trans. Gcol. 

 Soc, 2nd ser. vol. iii. p. 93. 



