392 Rev. R. Arlington Bullen — 



of its depth. Taking the average depth as 8 inches, this would give 

 a removal of 100 feet of denuded strata from above the Walsinghani 

 formation. However, this is not all the waste. This dissolving in 

 all probability took place mostly in Pliocene and partly in early 

 Pleistocene times. Some solution is, of course, also still going on 

 slowly. But the total denudation of this period is probably for the 

 average of 18 inches of soil (red) at least 225 feet. The proportions 

 of the red soil vary greatly according to the source of the sample 

 analysed. The shell-sand contains from '005 of earthy impurities 

 upwards (insignificant as this seems it amounts to 5 tons of every 

 thousand dissolved), and the analyses show calcic carbonate, as well 

 as oxide and sulphate, magnesic carbonate, alumina, ferric oxide, 

 sand, insoluble clay, silica potash, soda, carbon dioxide, etc. 1 



Dr. A. Puissel Wallace thought that the red earth was produced 

 from pumice thrown up by the sea. But, as Agassiz says, "Although 

 I examined the beaches of the south shore many times, I never 

 succeeded in finding a single piece of pumice, lied earth is abundant, 

 both in the Bahamas and Bermudas, in localities to which drift pumice 

 could not have access." 2 These red layers, from 2 to 10 inches 

 thick, interstratified with the limestone of the Walsingham period, 

 are clearly seen in several sections. The 8 inch upper layer becomes 

 a line of demarcation as good as we are likely to obtain. This red 

 soil was proved at Prospect Hill, in a military boring at a depth of 

 130 feet and at 65 feet above O.D. 3 As the same red clay descends 

 nearly to the shore at Hamilton, an ideal section of the underlying 

 Walsingham rock would be of a saddle shape, taking the direction of 

 north and south, and the Devonshire and Paget formations would lie 

 against or above it respectively. The Walsingham formation probably 

 underlies the whole length of the islands and reaches its greatest 

 height somewhere about Prospect Hill or Sears Hill, though it is 

 about 50 feet or so below O.D. at and near Ireland Island. 



On Mr. Richard Kempe's land in Warwick parish the underlying 

 rock is of a hard crystalline nature and the soil is red but not very 

 deep, and on the northern slope, about the 50 feet contour, the 

 limestone is of a crystalline nature, with veins of fine calcific crystals 

 resembling the calcite of the Oreston Cave, near Plymouth. Every - 

 whei'e I examined the same fact holds good, the red soil is underlain 

 by hard rock. 



Verrill considers that most of the serpuline atolls and outlying flat 

 reefs of the south coast are composed of the hard limestones of the 

 Walsingham period, although the characteristic extinct fossil land- 

 snails have as yet not been found in these reefs. 4 



(2) The Devonshire Formation. There has been much discussion 

 about the position and date of the beach rock. Some of the older and 

 more elevated of the beach rocks indicate that they were formed in 



1 Verrill, " The Bermuda Islands : Geology " : Trans. Conn. Acad. Arts Sci., 

 vol. xii, pp. 490, 493. 



2 A. Agassiz, op. cit., p. 236. 



3 The thickness was 8 inches according to Goldie, Lecture on the 

 Geological Formation of Bermuda, 1893, pp. 14, 15. 



4 Op. cit., p. 73. 



