228 GEOLOGY OF THE ISLE OF WIGHT. 



the valley, in a excavation on the site of the lower hotel, and 

 where the specimen is now preserved ; the other was procured 

 from the beds on the east side."* 



North of the gap through the Downs the Gravels have not 

 yielded fossils, though they form sheets of considerable extent. 

 From the scarcity of sections it is also difficult to say whether these 

 deposits belong to one period or mark successive stages in the 

 denudation of the valley. 



In the sheet of gravel whicli extends to Freshwater Bay a pit 

 has been opened at Easton at a height of about 50 feet above 

 the Alluvium, but the gravel slopes continue down to the Marsh, 

 On the opposite side of the Yar the gravel occupies a plateau 

 from 30 to 50 feet above the sea, and a pit shows 25 feet of coarse 

 gravel resting on Bagshot Sands. In Afton P;irk a large pit was 

 opened to supply ballast during the construction of the railway. 

 It showed about 6 feet of gravel, resting in one place on shelly 

 clay — probably Barton Clay — but the gravel itself yielded no 

 fossils. The sheets further north show no sections, and are 

 only interesting as fringing the present estuary. 



IV. — Beds now Forming, or of Kecent Date. 



In this group we include Alluvium, Peat, Blown Sand, Chalk 

 Talus, Tufa, &c. Chronological arrangement being impossible 

 among such beds, the Alluvial Deposits will be taken in the 

 geographical order of the streams with which they are associated. 



Alluvium and Peat. 



a. The Western Yar, and the Coast from Freshioater to Yarmouth.. 



The small stream which now follows the old valley of the Yar 

 takes its rise at Freshwater Gate in a spring known as the Rise 

 of Yar, situated on the eastern edge of the Alluvium at a 

 distance of 200 yards from high-water mark. Though fresh, this 

 spring ebbs and flows coincidently with the tide. In dry weather 

 it ceases to flow soon after the tide begins to fidl. 



The Alluvium, consisting of peat, silt, and marsh clay, extends 

 continuously southwards to the foreshore, where, however, it is. 

 almost always covered with sand and shingle. In digging a 

 foundation for the sea-wall, this peaty deposit was excavated to a 

 depth of 10 feet without the bottom being reached, and was 

 found to be abundantly charged with fresh water. The ponding 

 back of this water by the rising tide is probably the cause of the 

 spring alluded to above. 



The tide flows up the Yar as far as Freshwater, where it is 

 stopped by a dam. Formerly the whole of the marsh must have 

 been part of the estuary, for shells of the common cockle occur 

 abundantly just below the peat opposite Afton House. 



* The Tertiary Fluvio-Murine Formation, &c., p. 5. 



