ENGLAND 



ENGLAND 



as the marine deposits of the several 

 geological ages have permanently 

 emerged from below the sea. 



The old western lands occur in 

 three portions. The Lake District 

 is the oldest, with Ordovician and 

 Silurian rocks and large massive or 

 eruptive basalt. The Cornish penin- 

 sula and Herefordshire are mainly 

 Old Red Sandstone and Devonian 

 rocks with eruptive granites in 

 Cornwall. Here the rivers have 

 bitten into the rocks and carved 

 the upland into steep-sided, nar- 

 row, winding valleys. Between 

 rounded smooth-topped ridges and 

 domes lie marshy alluvial flats, 

 where the streams meander across 

 valley bottoms made by more 

 powerful torrents. In the Lake Dis- 

 trict the ice sheet gave a slightly 

 different character to the land sur- 

 face, and in the valleys carved by 

 glaciers long narrow lakes walled 

 by steep slopes radiate from a' cen- 

 tral knot of mountains. 



Between the rivers Tweed and 

 Trent the carboniferous rocks form 

 a chain of uplands which make a 

 definite water-parting between the 

 rivers of the North and the Irish 

 Seas. Flanking the Pennines are 

 the coal measures, which lie in pairs. 

 In the N. the Cumberland and Dur- 

 ham and Northumberland coal- 

 fields reach the coast; S. of the 

 range the Lancashire and N. 

 Staffordshire coalfields on the W., 

 and the York, Derby and Notting- 

 ham coalfield on the E., lie on the 

 slopes between the watershed and 

 the almost flat plains of Cheshire 

 and the vales of York and Trent. 



Farther S. the carboniferous 

 rocks only appear in detached frag- 

 ments in the midland coalfields be- 

 tween the Trent and the Stratford 

 Avon; in the mountain limestone 

 and the Forest of Dean coalfield on 

 the edge of the Old Red Sandstone 

 of the Wye and Usk. 



The New Red Sandstone 



On the E. margin of the car- 

 boniferous rocks, along a line from 

 the mouth of the Tyne to that of the 

 Exe, are detached portions of the 

 Permian system. FromTynemouth 

 to Nottingham both Permian sand- 

 stone and magnesian limestone 

 appear in long narrow bands. 



Triassic rocks cover a V-shaped 

 area reaching from Middlesbrough 

 to Gloucester, and from Gloucester 

 to the shore of Morecambe Bay. De- 

 tached portions fringe the coast of 

 the Lake District, form the valley 

 of the Lower Eden, and extend 

 across the isthmus of the Cornish 

 peninsula. Their best known repre- 

 sentative is the New Red Sand- 

 stone. Triassic rocks are asso- 

 ciated with lowlands, the vale of 

 York, the valley of the Trent, 

 the Cheshire plain, the Fylde of 



Lancashire, and the lowlands W. 

 of the Severn. 



The remaining portion of Eng- 

 land comprises rocks which have no 

 representatives on the W. The 

 Lias stretches in an almost un- 

 broken band from Lyme Regis, E. 

 of the Severn and the Stratford 

 Avon, E. of the Trent, and from 

 Goole to the coast near the mouth 

 of the Tees. Fringing the lias along 

 its eastern margin lies the oolitic 

 limestone, which gives rise to a 

 line of residual hills, from the 

 Cotswolds to the N. York moors. 



Between the Wash and Dorset a 

 narrow band of Greensand separ- 

 ates the oolite from the chalk which 

 gives rise to a series of hills the E. 

 Anglian Heights, the Chilterns, the 

 Marlborough, and N. and S. Downs. 

 Within the V-shape of these hills 

 lies the London basin with its young 

 rocks. 



The N. and S. Downs are relics of 

 a ridge of chalk which was raised as 

 the Wealden uplift to form a con- 

 tinuous ridge from Wiltshire to 

 France. The middle of the ridge 

 has been worn away to form the 

 Wealden plain and expose the 

 Greensand along the inner scarped 

 edge of the chalk, the Wealden 

 clay within the Greensand, and 

 the Hastings Sand within the clay. 

 Scenic Differences 



Each of these geological horizons 

 has been weathered into character- 

 istic land forms. The steep cliff 

 faces of the Millstone Grit in Derby- 

 shire are in striking contrast to the 

 chalk landscape of the downs, 

 marked by rounded contours. The 

 Triassic landscape of the vale of 

 Trent or the Cheshire Plain differs 

 widely from either the oolitic 

 Oxford Clay or the younger London 

 Clay of Herefordshire or Middlesex. 



These scenic differences are em- 

 phasised by the vegetation typical 

 of each type of rock. The beeches 

 and silver birches of the sandstone 

 of Sherwood Forest differ widely 

 from the woodland which clothes 

 the sides of the narrow Cornish 

 valleys and leaves the uplands bare. 



Similarly, the coastal edges of the 

 formations give an infinite variety 

 to the shores of England. The 

 chalk cliffs of Dover and Beachy 

 Head, with their vertical white 

 faces, differ from the sandy cliffs 

 exposed near Bournemouth in the 

 eocene of the Hampshire basin ; the 

 miles of iron-bound coast along N 

 Cornwall from Tintagel southwards 

 are totally different from the sandy 

 lowland shores of the Triassic for- 

 mation in the Wirral peninsula. 



RIVERS AND VALLEYS. Although 

 the highest ground of England is 

 largely due to those foldings of the 

 earth's crust which produced the 

 Pennine and Wealden uplifts, the 



residual features are largely the 

 work of rivers. In the N.E., in 

 Northumberland and Durham, the 

 North Sea drainage reaches to a 

 water-parting on the western side 

 of the Pennines ; near Cross Fell 

 (2,930 ft. ) the Tyne, Wear, and Tees 

 rise close to each other. From 

 Haltwhistle the S. Tyne and the 

 Tyne itself flow due E. ; the valley 

 of the S. Tyne leads W. through 

 the Tyne Gap in the Pennines at a 

 lower elevation than 500 ft. to Car- 

 lisle. The Coquet, Wansbeck, and 

 Blyth cross the coastal plain of 

 Northumberland, and the Wear 

 and Tees for more than half their 

 length are on the Durham lowland. 

 River Drainage 



Between Teesmouth and the 

 Wash almost the whole of the 

 drainage is concentrated on the 

 Humber. The large rivers, except 

 the Yorkshire Derwent, rise to- 

 wards the W. side of the Pennines, 

 the Trent even on the western 

 slopes, and drop through the 

 dales to the level of the Trias- 

 sic sandstones and marls in the 

 plains of York and Trent. Rich- 

 mond, Leyburn, Ripley, Shef- 

 field, Stoke-on-Trent, the first 

 large places on the rivers, mark 

 the termination of Pennine valleys. 

 Lower down stream the rivers flow 

 over the sandstones to the main 

 streams of Trent and Ouse which 

 flow parallel and close to the E. 

 edge of the Trias. 



The drainage has hollowed the 

 sandstone into a trough with Lias 

 clays on the E. The Yorkshire 

 Derwent is the one exception 

 to the rule that no long rivers 

 cross the Lias to the Triassic plain. 

 This stream rises close to the 

 coast, flows across the oolitic vale 

 of Pickering between the Cleve- 

 land Hills and the Yorkshire 

 wolds in an abnormal course 

 which was determined originally 

 by the presence of sea ice during 

 the ice age in the North Sea. This 

 ice barrier forced the drainage 

 towards the S.W., so that a per- 

 manent valley was carved across 

 the Lias clay. 



The Wash, Witham, Welland, 

 Nen, and Great Ouse rivers rise 

 on or close to the Lias, and carv- 

 ing out the low residual oolitic hills, 

 drain the trough of clayey land 

 bounded on the E. by the chalk 

 ridge N.E. of the Chilterns. The 

 water gap at the great bend of 

 the Witham is dominated by the 

 city of Lincoln on the oolite ridge 

 above the river. 



Probably the* Thames once 

 flowed over dry land to join the 

 Rhine and make a great river 

 which flowed N. across the North 

 Sea floor. The Yare, Waveney, 

 Orwell, Stour, Colne, Blaokwater, 



