Journal af Froceedimjs. xiii 



Satukday, May 14th, 1881. — Field Meeting. 



ExcuKsioN TO Gkays Thukkock, Essex. Conductors: Pkofessok John 

 Morris, M.A., F.G.S., and Henry Walker, Esq., F.G.8. 



[For the Geological x>ortioiiH of this report the Editor /.s indebted to the 

 kindness of Mr. Walker, who supplied the admiraUe resume embodied 

 in the folloicimj payes.] 



This being an excursion in conjunction with the Geologists' Association, 

 the members of the two Societies assembled in very considerable numbers, 

 leaving Fenchurch Street Station by the 2.25 p.m. train. The route for 

 almost the entire distance lies across the gravel and alluvial flats of the 

 Thames Valley. The wide and shallow tributary valleys of the Lea and 

 the Eoding, as they were successively passed, were well seen. During the 

 remainder of the journey the nearer features southwards are the levees 

 confining the Kiver Thames within its modern artificial channel, whilst 

 beyond is seen the bold and natural horizon formed by the chain of hills 

 stretching from Greenwich to Erith, the southern limit of the valley along 

 that line. On nearing Purfleet, the western outcrop of the small area of 

 chalk which is found in South Essex begins to be visible. On nearing the 

 station, and looking to the left-hand side of the railway, an old chalk-pit, 

 abandoned now to the botanist and entomologist, reveals both the chalk 

 and the Thanet sand, the latter capping an isolated mass of the former. 

 Past the station the bare sides of the great conical mound of Thanet 

 sand, having a high angle of rest, and being a very conspicuous object 

 from the Erith side of the river, is close at hand. The remaining tlu-ee 

 or four miles of the journey lie along the West Thurrock Marshes, but on 

 the left the presence of the chalk skirting the railway is told by its 

 characteristic contours. 



Alighting at Grays, the party received some notable reinforcements, and 

 the united forces, considerably exceeding one hundred in number, were 

 conducted by Mr. Walker to the high road leading to Stifi'ord. Here the 

 extent and position of the three southern chalk-pits are well seen ; the 

 East Pit ; the Central Pit (appropriated for the manufacture of whitening) ; 

 and the Western Pit, occupied by the South Essex Waterworks Company. 

 Attention was called to the flooded condition of the Eastern Pit, the floor 

 having been worked down to the level of the springs, and the pumping 

 being temporarily suspended. The sides show the green-flint bed lying on 

 the surface of the chalk, and the Thanet sand above. The islands below, 

 overgrown at the surface with vegetation, but revealing on their bare 

 sides a sharp dip of their component strata, were here the subject of some 

 cautionary remarks ; their real character as spoil-heaps, or " tips "' of 

 Thanet sand and gravel, has not always been recognised, even by geological 

 visitors. A descent to the central pit was then connnenced. On the way 

 one of the Greywethers or Sarseu-stones, for which Grays has long been 

 notable, was found lying on the unworked surface of the chalk, at a spot 



