ISO 



It is this system ■with which vre are chiefly concerned in 

 Cleveland. It is out of these rocks that the fair scenery of the 

 district has been so deftly carved. To them, therefore, it is 

 necessary to give special attention. They consist of the Lias 

 behnv and the Oolite above. The Lias is divided into lower, 

 middle and upjier. The Lower Lias, which is about 750 feet 

 in thickness, is chiefly composed of easily denuded .shales. The 

 best exposure in our area is on the shore at Redcar, but we 

 often get a peep at it in the beds of streams, as about Easby 

 and Great Ay ton. The Middle Lias is composed to a large 

 extent of harder beds, beginning with hard shales, continuing 

 upwards into sandstone, and concluding above with the ironstone, 

 which forms the most important mineral jiroduct of Cleveland. 

 The entire thickness of the Middle Lias is aliout -ioO feet. The 

 Upper Lias, from 50 to 200 feet in thicknes.^^, consists of the soft 

 beds of Jet and Alum Shales. 



Superposed upon the L^pper Lias are the hard estuarine 

 sandstones of the Inferior Oolite. These are massive and 

 moderately resistent to disintegration, and consequently stand out 

 all round the edge of our Cleveland Moors as a prominent 

 escarpment— an often perpendicular wall — capping a steep face of 

 Upper Liassic shales. This light sandstone wall, surmounting 

 here a dark blue scarp of bare shale and there a gentler slope of 

 green grass-clothed moor bank, gives to our district one of its most 

 characteristic features. 



In the sea-clifls of the Yorkshire Coast the lower Oolites up 

 to the Cornbrash have a thickness of nearly 700 feet, but they 

 thin out westwards and southwards. They are full of plant 

 remains, and thin seams of coal also occur. A hard bed, which 

 by reason of its hardness often stands oiTt and forms a prominent 

 feature, is known as the Moor Grit. 



Capping the Inferior Oolite comes the Cornbrash, Avliich is a 

 softish limestone, not averaging more than ten feet in tliickness 

 in North Yorkshire. 



The highest of the Jurassic rocks occurring in Cleveland is 

 the Kellaways Rock, which occurs at the liase of the middle 

 Oolites, and is a sandstone variable in its character This we 

 find preserved in a .syncline in the neighbourhood of Freeborough 

 Hill. The rest of the middle Oolites — the Oxford Clay, the 

 Corallian Series, the Kimeridge Clay and the Portland Beds — 

 are wanting in our area. Proliably they most or all of them once 

 extended over it, and it is not easy to resist the conclusion that 



