XXII. 



probably only travelled a short distance, and point to the proximity of 

 -an Arctic Flora. But before describing the drift itself, mention must 

 be made of a bed which lies unconformably on the crags, and which is 

 overlaid by the drift the Westleton Beds, a deposit of gravel so-called 

 from the locality where it is best developed. They may be also seen in 

 the Valley of the Bure and at Easton Bavent. In the lower part of the 

 beds is found that characteristic Northern fossil species Tellina balthica. 



From the evidence of scratches on rocks, and the presence of 

 -erratics, the whole of Northern Europe must have been in part covered 

 by an extensive ice sheet, continuous with huge glaciers coming down 

 from the mountains, and filling up the North and Irish Seas. 



The several beds of drift point to as many separate glaciations 

 interrupted by intervening periods of warmer climate, during which the 

 ice sheet receded. The Lowest glacial bed of the Eastern Counties 

 is known as the contorted drift, so well seen at Cromer, and which ex- 

 hibits stratification with strange twistings in the beds. This bed is 

 supposed to have been deposited at the bottom of a sea and to be the 

 remains of a moraine terminating below its waters. The contortions 

 have been caused by the grounding here and there of huge icebergs or 

 of coast ice driven aground. The boulders in this drift are mostly chalk 

 and flint, but fragments of Carboniferous and Oolite rocks with pieces 

 of basalt, granite, quartzite, &c., are common. In places fragmentary- 

 marine shells are to be obtained. In Suffolk this bed consists of a 

 yellowish brown brick earth, with occasional beds of sand and gravel. 



Above the contorted, or lower drift beds, are beds of sand and 

 gravel (middle drift sands), which correspond to a warm inter-glacial 

 period. These beds occur here and there, more frequently in the 

 Eastern part of the County, and are of great interest at Brandon, at 

 which place Mr. Skertchley has found them to contain flint implements. 

 These beds usually unfossiliferous yielded at Hopton Cliff,near Gorleston, 

 shells of a Southern type, and similar specimens are stated to have 

 been found near Halesworth and Newmarket. 



The Great Chalky Boulder Clay, which represents the second great 

 period of glaciation, is well developed in our County, both as regards 

 the area of its extent and the thickness of the deposit, reaching near 

 Bury St. Edmunds 100 feet in depth. It is composed of a dirty grey 

 clay, full of pieces of chalk, with frequent boulders of Lias and Oolite 



