[ 126 ] 



^XI> On the Anticlinal Line of the London and Hampshire 

 Basins. By P. J. Martin, Esq., F.G.S. 

 [Continued from p. 51.] 

 Anticlinal Line of the Vale of Greenhurst. 



ALTHOUGH a description of this line of elevation forms a con- 

 spicuous feature in my former disquisition on the Weald*, 

 in resuming this part of my subject I may be supposed to be in- 

 vading a province which Mr. Hopkins has in some measure made 

 his own, by the labour he has lately bestowed on it, with which, 

 however, I was till very recently unacquainted. Of the result 

 of Mr. Hopkins's investigation into the construction of the body 

 of the Weald I am entirely ignorant. I have long been familiar 

 with most of its phsenomena ; and have, since the publication 

 of my former essays, been waiting for a favourable opportunity 

 of publishing the results of my observations in the shape of a 

 " History of the Weald Denudatiou.^^ But as I am not yet 

 prepared to fill up all the details of such a history, I am better 

 pleased that an exposition of the construction of the Weald and 

 the Boulonnais should come from the author of a " Theory of 

 Elevation." 



On looking at the escarpment of the South Downs in No. 9 

 of the Ordnance Map, it will be observed that there is a remark- 

 able recession of that escarpment southward, between the salient 

 angles of Duncton Hill in the west of Sussex, and Wolfstanbury 

 in the east. In a line parallel with this receded chalk, and at 

 an average distance of about a mile, lie the Weald-clay valleys 

 of Greenhurst and Henfeld — ^^ valleys of elevation," — with their 

 anticlinal escarpments of lower greensand, and their synclinal 

 reduplications of the same, with the occasional addition of a 

 trough of gait ; the whole occupying a length and breadth of 

 country of about eighteen miles by from one to two. 



Greenhurst lies on the road between Storrington and Thake- 

 ham. Mary Hill on the south and Jacquet's Hill on the north 

 form its scai'ped anticlinal boundaries of lower greensand, show- 

 ing a dip which varies from 30 to 60 degrees. Here the syn- 

 clinal line loms in the valley in which Abbingsworth House and 

 Champion's Farm are situate ; and the beds which dip north at 

 Jacquet's Hill rise north again in the hollow way to Thakeham. 

 East of Greenhui-st the northern escarpment breaks ofi" at the 

 high grounds of Warminghurst, and the valley opens into the 

 great expanse of the Weald. The anticlinal line is ^then carried 

 on in a Weald-clay saddle through Ashington, Guesses' Farm 

 and Horsebridge Common. It next crosses the Adur, and is 

 * Memoir on Western Sussex, &c. 



