Vol. 58.] A DEEP BORING AT LYME REGIS. 287 
many layers and beds of gypsum were traversed, varying in thickness 
from a few inches to more than a foot. 
At a depth of 730 feet a ‘grey siliceous marl’ was noticed, 
meaning probably a fine sandy clay; and at 828 feet a bed termed 
a ‘limestone’ was met with, but no sample of either of these beds 
has reached me. 
Between the depths of 840 and 864 feet three beds of grey 
caleareous sandstone were traversed, each from 12 to 15 inches 
thick, and separated by beds of red and grey gypsiferous marl. It 
might have been supposed that these represented the alternations of 
sandstone and marl which are seen in. the lower 150 feet of the 
Keuper Marls near Sidmouth; but if they had been, the Keuper 
Sandstones (75 feet), the coarse Bunter Sandstones (300 feet), and 
the Budleigh Salterton Pebble-beds (80 feet) would have been 
found below. Instead of any of these, another thick series of red 
and variegated marls and clays was found to le below, and to 
continue for more than 400 feet. 
It is highly improbable that the Bunter Sandstones and Pebble- 
Beds should have thinned out entirely between Sidmouth and Lyme; 
and, further, it is impossible to correlate the lower marls of the Lyme 
boring with the marls which underlie the Budleigh Beds, because 
the former are gypsiferous throughout, while the latter do not 
contain gypsum. 
We are, therefore, obliged to conclude that the calcareous sand- 
stones are simply sandy beds intercalated in the Kéuper Marl 
Series; and there is nothing very remarkable in the fact of such 
intercalation. Indeed, there appear to be similar beds near 
Taunton and North Curry in Somerset ; for Charles Moore noted the 
occurrence of thin beds of dull-grey and brown sandstone in 
the lower part of the Keuper Marls near Ruishton and North 
Curry, about 60 feet of marl being exposed below them at the 
latter place.’ 
Among the samples from the lower 150 feet traversed by the 
Lyme boring, there is nothing which can properly be termed a 
sandstone: because, though fine sand is undoubtedly a constituent 
of some, it is so fine and so mixed with argillaceous and micaceous 
matter, that to call the rock a sandstone would convey an erroneous 
idea of its character. Some of the beds might be called ‘silt- 
stones,’ having originally been silty muds, but others are simply 
hard clays; and the hed in which the boring ended at 1302 feet is 
a hard, dull-red, silty clay, containing many glistening flakes of 
silvery mica. 
I am, therefore, forced to conclude that the boring did not reach 
the beds which near Sidmouth form a passage from the Keuper 
Marls to the Keuper Sandstones; that the depth of Keuper Marls 
proved by the boring is about 1130 feet; and consequently that 
the total thickness of these marls must be greater than that amount. 
If we add to these figures the thickness of the passage-beds near 
1 See Quart. Journ. Geol. Soc. vol. xvii (1861) p. 486. 
