A HISTORY OF LANCASHIRE 



MESOZOIC PERIOD 



The formation of the red sandstones and marls which we have considered under the name of 

 Permian brought to a close that period of geological time known as Palaeozoic, and was m turn 

 succeeded by the Mesozoic, in which higher orders of animals and plants appeared, and m which the 

 rocks were less mechanical in origin, and owed more to accumulation in quiet waters and the 

 aggregation of the remains of various life forms. The rocks of this period have also suffered much 

 1^ by earth movement and change than the older rocks. The distinction between Paleozoic and 

 Mesozoic rocks is a purely arbitrary one, retained for convenience, but possessing no actual 

 justification, as in many places no satisfactory line can be drawn between the Permian and the 

 Trias, the one apparently passing gradually into the other. 



TRIAS 



The various members of the Triassic System which are represented in Lancashire are the 



following : — 



/ Keuper or Red Marls. 

 Upper Trias or Keuper . . . . <^ Keuper Sandstone. 



f Upper Red Mottled Sandstone. 

 Lower Trias or Bunter . . . . s Lower and Upper Pebble Beds. 



[ Lower Red Mottled Sandstone. 



The Triassic rocks occupy a large extent of the flat country forming the Lancashire sea-board 

 from Liverpool to Morecambe Bay, which it encircles as far as Walney Island and the south part of 

 the Furness district. The greatest breadth of this lowland plain is in the neighbourhood of Preston, 

 where it is about 20 miles across. The Triassic beds have been brought against the edges of 

 the older rocks by a great fault system in post-Triassic time, with a western downthrow. 



BUNTER 



The Bunter Sandstone and Pebble Beds are well developed in the neighbourhood of Liverpool, 

 where they have received considerable attention from local geologists. The Bunter Sandstone 

 usually lies deep, but could formerly be seen at Eastham and Ince before the making of the Man- 

 chester Ship Canal. It is also seen at Eccleston Hall, near St. Helens. The beds are famous for 

 the amount of water they contain, and many borings have been put down into them, from which 

 a huge supply is obtained. The Pebble Beds are well exposed near Liverpool, and in quarries at 

 VVavertree, the section at Olive Mount being especially good. By the late G. H. Morton they 

 were divided in the Liverpool area into Lower and Upper Pebble Beds, the latter containing few 

 pebbles. 



The Upper Red Sandstone is exposed in nearly all the railway cuttings on the north, east, and 

 south of Liverpool, and it lies in massive beds often of a bright red colour, streaked with grey. At 

 Liverpool it is usually too soft to use as a building stone, but at Frodsham, Runcorn, and Ormskirk 

 it is very hard, although it weathers badly. 



KEUPER 



The Keuper Sandstones and Marls which form the Upper Trias lie at the surface to the west 

 of the Bunter series, the two running side by side from Liverpool northwards, the Keuper Series 

 forming a goodly portion of the coastline, though occasionally obscured under a heavy load of 

 Glacial drift, or Blown sand. At one time the Keuper Sandstone was extensively quarried at 

 Liverpool, the lower beds forming a good building stone. That obtained from Runcorn is even 

 more durable. Just outside the county boundary at Storeton in the Wirral peninsula, extensive 

 quarries are opened in the Keuper Sandstone, and have yielded sandstone slabs showing a most 

 interesting series of footprints, ripple markings, and rain pittings. The footprints, which are of large 

 size and five-toed, are believed to have been made by an amphibian closely allied to, if not identical 

 with, the Labyrinthodon. To the animal which made them the name of Cheirotherium has been 

 given. To smaller footprints of a different type the name of Rhynchosaurus has been given. 

 Remains of the latter have also been found in Warwickshire. 



The Keuper Red Marls consist of red and grey marls and shales, with bands of sandstone. The 

 thin flaggy sandstones are often ripple-marked, and their surfaces are at times studded by beautiful 

 pseudomorphous crystals of common salt. A large area of the Red Marls stretches from Formby to 

 Southport, having been proved by borings, but it is all deeply covered by drift. At Runcorn the 

 Alarls are seen on the banks of the Weaver. Near Fleetwood, at Preesall, a boring put down in the 



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