148 SUBTERRANEAN GEOLOGY OF SOUTH-EASTERN ENGLAND.
belief which the results of the researches of Prof. Gosselet after-
wards led him to abandon. Since the reading of Godwin-Austen's
paper, all the deep borings in or east of London, of which I am about
to speak, have been made, and they have certainly verified his
theoretical predictions in showing the otherwise unexpected nearness
of a ridge of Palaeozoic rocks in the valley of the Thames about
London, though no coal-measures have yet been found there. In
the volume of the "Quarterly Journal of the Geological Society"
which contains Godwin-Austen's paper, appears one by Mr. Prest-
wich (read a few months later) "On the boring through the Chalk at
Kentish Town, London." In this case 325 feet of Tertiary Beds
were pierced through, then 645 feet of Chalk. Below the Chalk were
13 feet of Upper Greensand, and 131 feet of Gault. But instead of
Lower Greensand and other Lower Cretaceous or Jurassic rocks, the
Gault was found to rest on red sands, sandstones, and clays, which
are now regarded by Prof. Prestwich as probably Upper Old Red
Sandstone, and by Mr. Whitaker as more likely to belong to the
Trias.5 But at first the result of this Kentish Town boring seemed
so startling that Mr. Prestwich was inclined to think these red rocks
of Lower Greensand age, being led to alter his view in consequence
of the evidence of other deep borings within a few miles of Kentish
Town have which since penetrated to Triassic or Palaeozoic rocks at
similar depths.
The deep borings in South-eastern England that have reached
either Triassic or Palaeozoic rocks are seven in number, and are
situated at Kentish Town ; Meux's Brewery, London 5 Richmond;
Crossness near Erith; Cheshunt; Ware ; and Harwich (see fig. 3).
While four others of equal or greater depth, but ending in Jurassic or
Cretaceous rocks below the Gault exist at Loughton, Essex; Chatham,
Kent; Netherton near Battle, Sussex; and Dover, Kent.
The Chalk in the borings in the neighbourhood of London was
very uniform in thickness. The following were the results :—
5 "Guide to the Geology of London," Ed. 4, 1884. As the thicknesses of beds given by
Mr. Whitaker sometimes differ from those of Mr. H. B. Woodward, I have indicated my
authority in certain cases by the letters (Wh.) or (Wo.)