TIIK PLEISTOCENE SERIES 645 



occasionally l>y iiu-u of early Palaeolithic race. In the cave earth 

 hya-na bones are the most abundant, but remains of twenty- 

 five other mammals were found, including Elephas primigenius, 

 llhinnceros tichorhinus, and Rangifer tarandus. With these were 

 associated flint implements of two recognised Mesolithic types and 

 a l\-\v tools made of bone. This deposit evidently represents a long 

 period of time, and is covered by the upper stalagmite containing 

 remains of hya-na, mammoth, fox, and horse. 



Raised Beaches. Eaised beaches and sea -margins occur 

 along many parts of the British coast-line. The beaches consist 

 of sand and gravel, irregularly stratified, and often containing 

 drifted shells, such as may be found on modern shores. Deposits 

 of this kind occur at Brighton and westward along the southern 

 part of Sussex as far as Portsdown Hill, the highest level at which 

 they are found being about 130 feet above the sea. Inland they 

 are banked against an old line of cliffs, the position of which is 

 shown in Fig. 173. Raised beaches exist also at Portland Bill, 

 where the highest part of the deposit is 50 feet above sea-level, 

 and at many places round the coasts of Devon and Cornwall. 27 All 

 these are probably contemporaneous with the raised beaches of 

 South Wales (see p. 632), which are older than the local Glacial 

 deposits, and in fact of meso-Glacial age. 



On the Scottish coasts raised beaches and lines of cliff are 

 found at various successive levels between 25 and 100 feet above 

 high-water mark, four or five sometimes occurring one above 

 another. These are of more recent age, the highest being contempor- 

 aneous with latest moraines. 



Alluvial Levela These are marshy flats formed of the 

 deposits left by the flood-waters of a river ; they border the actual 

 channel of the river and widen out in the lower part of its valley, 

 till near the river's mouth they often form wide levels or marshes, 

 which are partly of fluviatile and partly of marine origin. The 

 depth of alluvial matter which occupies the ancient valleys of our 

 rivers near their mouths is sometimes very great ; thus at Sheerness, 

 and also at Upchurch, near Sheppey Island, borings have proved 77 

 feet of such alluvium. In the Essex marshes there is sometimes 

 60 feet of alluvial matter. At Yarmouth there is said to be 

 170 feet, and in the valleys of the Yare and Wensum there appears 

 to be sometimes 60 or 70 feet of alluvium between the present 

 surface and the chalk which lies at the bottom of the valley. 



Besides the deposits above mentioned which lie within river- 

 valleys, there are other tracts round our shores which have once 

 been bays and inlets of the sea, and are now filled principally 

 with marine silts and clays, though layers of peat with trunks of 



