Alfred J. Browne — The Valley of the Tar. 561 



Srd. Mr. Forbes states that a parallel structure, equally, if not 

 better, developed than any occurring in the gneiss of Donegal, is 

 common to many volcanic rocks. I know that my friend is in the 

 habit of carrying about in his pocket bits of lava or recent slag with 

 this banded or ribboned structure. So seldom is he without one 

 such specimen that he runs the risk of being looked upon by the 

 vulgar as a believer in talismans or charms ; for on no other ground 

 could they explain his apparent attachment to these pretty speci- 

 mens. Eeally he uses them to crush rash theorizers like myself by 

 bringing them forward as proofs that rocks may be of igneous origin 

 and still bedded ; but I cannot imagine that there is any danger of 

 confounding bedded structure on a large scale with the lamination 

 of such specimens as Mr. Forbes is in the habit of basing his argu- 

 ments on. In hand-specimens it might be difficult to distinguish 

 between the two ; but in the field I do not think that any one accus- 

 tomed to the look of rocks could mistake one for the other. 



VI. — The Valley of the Yar, Isle of Wight. 

 By Alfred J. Browne, Esq. 



IT may seem superfluous to describe any part of such a well-known 

 district as the Isle of Wight ; but although its geology has been 

 so well investigated, still the Post-Pliocene deposits of the island 

 have perhaps received less attention than any others. The origin of 

 its valleys, moreover, has not, so far as I am aware, been carefully 

 studied ; and as it may throw light on the date of formation of 

 the Solent and Spithead, I venture to send a few notes made on a 

 recent examination of the valley of the Yar, in the hope they may 

 prove interesting, even if not original. 



I will begin at its mouth. From Yarmouth to the village of 

 Freshwater, a distance of two miles, the river is estuarine and the 

 banks low and sloping. Freshwater is the present limit of the tidal 

 influence, and here the vallej^ is about 150 yards wide. Above this 

 it consists of a series of marshes about 100 yards wide as far as 

 Freshwater Gate, where the river takes its rise on the north side of 

 the shingle beach ; I say " takes its rise," in deference to its ancient 

 title and name of river, which it still retains, though there is now 

 no spring or stream, merely marshes and ditches, through which the 

 water soaks down to the estuary at Freshwater ; in fact, before the 

 beach at Freshwater Gate was raised and strengthened, these marshes 

 were often overflowed at high tides. So recent, however, does the 

 river-bed look that when standing on one of its banks in this neigh- 

 bourhood, it is difficult to divest oneself of the idea that the marsh}'- 

 grass in the bend of the valley is not rijopling water. 



Although the valley is now almost a dead level, the following con- 

 siderations seem to lead to the conclusion that it once had a greater 

 declination, not in the present direction, but on an incline from 

 Yarmouth to Freshwater Gate. 



VOL. VIII. — NO. xc. 36 



