ALLUVIUM AND PEAT. 235 



100 yards south of Walpen Chine. 



Feet. 

 Blo^vn sand, with fragments of shale and a few small stones - ?5 

 Blown sand, brown - - - - - - 3 



Grey silt .--..... \ 



Peaty layer ---.-._i 



Ochry layer and silt -.-.,. i 

 Grey silt ----.--.2 



Chert gravel - - - - - - -2 



The last section visible in the underclifF formed by the thick 

 clay which lies next below the Sandrock Series (p, 30), exposes 

 the following strata : — 



Feet. 

 Blown sand .-<-.._ 6_8 

 Yellow loam - - - , - - - - 4_6 



Chert gravel --..... 0-2 



South of this undercliff, the Blown Sand rests directly on the 

 rock. 



This large spread of gravel is clearly not the product of the 

 small sti'eam of Whale Chine, or of the stUl smaller one of 

 Walpen Chine, but may perhaps have been deposited by the upper 

 waters of the old Yar, of which the present streamlets were 

 tributaries. 



c. The Medina. 



The Alluvium of the River Medina commences at Chale Green, 

 and forms a long strip of marsh land, gradually widening to about 

 200 yards in the part known as the Wilderness and near 

 Gatcombe, but narrowing down as it passes the projecting spur 

 of Upper Cretaceous Rocks of Gossard HUI, and those of the 

 central range of the Island. The alluvial deposits are generally 

 marsh-clay and silt, with a black peaty soil on top. 



On the other hand the Alluvium of the tributary which joins 

 the Medina at Blackwater is principally peat, as perhaps the name 

 indicates ; its boundaries on the low watershed near Merston 

 are extremely indefinite, as described on p. 218. Below Newport 

 the Alluvium consists of estuarine clay and silt. 



d. The Eastern Yar. 



The Alluvium of the two longest feeders of this river, namely, 

 those which descend from Whit well and Wroxall, consists super- 

 ficially of a narrow strip of marsh-clay spread over the bottom of a 

 shallow trough cut through the Valley Gravels into the Lower 

 Greensand. The alluvial flat is bounded for some miles by a low 

 bank of Greensand with a thin covering of gravel. But the 

 streams which rise on the north side of Godshill, and join the 

 river above Horrlngford, drain some extensive peaty flats and are 

 bordered by peaty land, until they Join the Yar. The develop- 



