278 Paleo-Geological und Geographical Maps of the British Islands. 
referred to, and also partly to the decrease of sediment as we recede from the old 
lands which were the source of that sediment.* From this it may be concluded that: 
the land of the period lay to the north and west of the British Isles. It is also 
probable that Normandy and Brittany were portions of a land surface at the same 
period. The numerous beds of breccia and conglomerate in the Triassic strata of 
Devonshire indicate the proximity of land which may have included portions of 
Cornwall.+ In Ireland, the Trias is only represented in the north-east of the country ; 
and in Scotland, at the extreme south, and in the coast of the Moray Firth, near 
Elgin. It is probable that these countries were, over by far the greater part, in the 
position of land surfaces during the Triassic period. 
Nature of the Triassic Strata.—The Trias of Britain consists only of two divisions. 
The Bunter, or New Red Sandstone below, and the Keuper, or New Red Marl 
above. The intervening marine division of the Muaschelkalk being absent in 
Britain. The Bunter division consists of red sandstone and conglomerate ; the 
Keuper of red and variegated marls and sandy shales, containing gypsum and 
rock-salt, with beds of sandstone and conglomerate at the base. Their basement 
beds are, in reality an old shingle beach, formed around the flanks of the unsub- 
merged lands of the period. 
In order to account for the absence of the middle division in Britain, I have 
suggested that during the formation of the Muschelkalk in Europe, the British 
area was converted into a land surface. The slight unconformity of the Bunter 
to the Keuper division, and the eroded surface which the former often exhibits, go 
to confirm this view. 
It is probable that, as suggested by Sir A. C. Ramsay, the Triassic strata of 
Britain were deposited within the margin of an inland sea or lake. The boundaries 
of this lake towards the north and west are inferential ; those along the old ridge 
of the south of England have been partly determined by the aid of recent borings 
of the strata ; these borings may be briefly described in the following order :— 
1. Scarle near Lincoln. The Triassic strata were reached at a depth of 141 feet, 
and were found to be 1359 feet in thickness.§ The next (2), was at Northampton, 
at which the Carboniferous Limestone (as determined from the fossils by Mr. 
Etheridge), was pierced a short distance below the bottom of the Lias, at a depth 
* “ On the South-Easterly attenuation of the Lower Secondary Rocks of England.” Quart. Journ. 
Geol. Soc. vol. xvi. p. 63 (1860). 
+ These beds, including the Budleigh Salterton conglomerate, have been described by Buckland, 
Conybeare, and Murchison. The lower breccias were considered by these authors to be of Permian age. 
The section along the coast has been more recently described by Dr. Hicks, Mr. Ussher, and Mr. H. B. 
Woodward ; the last of whom gives a good summary of the views of himself and previous authors. 
“ Geol. Eng. and Wales,” p. 136, et seq. 
+ “The Triassic and Permian Rocks of the Central Counties.” fem. Geol. Survey. pp. 66, and 106. 
§“ Coalfields of Great Britain,” 4 ed., p. 261. 
