A HISTORY OF LANCASHIRE 



The lower zone lies in calcareous shales. Numerous other genera and species occur, amongst 

 them being Rastrites peregr'inus, Diplograptus Hughesii, CUmacograptus normalis, etc. Crustacea are 

 represented by trilobites such as Acidaspis, Preetus, Harpes, Phacops, Encrinurus, etc. ; brachiopods by 

 Lepttena quinquecostata and Atrypa Jiexuosa ; cephalopods by Orthoceras. 



Dr. J. E. Marr, when discussing the general facies of these beds.i drew attention to the fact 

 that the dominant forms were almost all Silurian, and indicated a relation to the May Hill beds of 

 Wales. A similar conclusion has been reached by other observers, and the beds together with the 

 overlying Browgill or Pale Shales series are now classed as equivalents of the Llandovery Group. 



The Browgill beds, which are frequently termed the Pale Shales, are very similar to certam 

 beds associated with the Graptolitic Mudstones. They have a thickness of about 1 30 feet, and have 

 yielded graptolites and brachiopods, examples of Monograptus lobiferus having been found in them on 

 Applethwaite Common, and Strickland'mia lirata in the Pale Shales of Rebecca Hill near Ulverston. 



CONISTON GRITS AND FLAGS 



Conhton Flags. — The Coniston Flags, which have a great thickness and are well exposed in the 

 Coldwell and Brathay quarries, about two miles south-west of Ambleside, consist of finely laminated 

 blue flags, overlaid by three series of flaggy and calcareous grits. Dr. Marr divides them as follows: — 



! Upper 

 Middle 

 Lower 



Brathay Flags. — The Brathay Flags are of fine texture, and cleave readily, and make up about 

 a third of the total thickness. They are sparingly fossiliferous, and have yielded Favosites aspera, 

 Monograptus priodon, Rettolites Geinitzianus, and a few other forms, chiefly in the neighbourhood of 

 Stockdale. 



The Coldwell Beds are made up of basal coarse grey grits, middle calcareous flaggy grits of a 

 blue colour and fairly fossiliferous, and an upper series of blue to grey gritty flags, which exceed in 

 thickness the middle and lower beds and Brathay Flags combined. 



The Upper Coldwell beds are well seen in a quarry 200 yards south of the Coldwell quarry. 

 The numerous fossils obtained from the Middle and Upper series include the corals, Petraia, and 

 Favosites fibrosa ; a trilobite, Phacops obtusicaudatus ; brachiopods such as Orthis and Strophomena, 

 cephalopoda, amongst which are six species of Orthoceras, and malacostraca ; Ceratiocaris and Peltocaris 

 being found in the upper beds at Troutbeck and Rebecca Hill. The Brathay Flags are of Wenlock 

 Group age, whilst the Coldwell Beds correspond to the lower portion of the Lower Ludlow Group. 



Coniston Grits. — These beds have a thickness of from 4,000 to 4,200 feet and consist of flags 

 and felspathic grits. In the Sedbergh district they have yielded a suite of fossils which show them 

 to be closely related to the Coniston Flags below, the grits and flags together corresponding to the 

 whole of the Lower Ludlow Group of Shropshire and Wales. 



BANNISDALE FLAGS 



This series of beds, which attains a thickness of over 5,000 feet in the adjoining counties of 

 Westmorland and Cumberland, consists of slates, grits and flags. Their representatives in the 

 Lancashire area are to be found in the Upper Ireleth Slate group described by Sedgwick in 1846, 

 who showed that they could be traced along the line of strike by Coniston Water and Windermere to 

 Long Sleddale and Bannisdale Foot. The great slate quarries at Ireleth are opened in these rocks. 



KIRKBY MOOR FLAGS 

 This group overlies the Bannisdale series beyond the Lancashire border on the north-east. 



OLD RED SANDSTONE 



Between the uppermost members of the Silurian in Lancashire which we have now dealt with, 

 and the Carboniferous, there intervenes the Old Red Sandstone, a great deposit of red and grey 

 sandstone, and flagstones, with conglomerates and shales. Although representatives of this system 

 occur in adjacent counties, there is yet no evidence of its occurrence within the county beneath the 

 Carboniferous Limestone. As, however, the Upper Old Red conglomerate underlies the Car- 

 boniferous Limestone in Cumberland, it is possible that if the base of the latter was exposed in 

 Lancashire, we should also find the conglomerate beneath it. The conditions which existed in 



1 ' On Some Well-defined Life-zones in the Lower Part of the Silurian (Sedgwick) of the Lake District,' 

 Quart. Joum. Geol. Soc. (1878), xxxiv. 879. 



