154 J. E. Marr—Drainage of the English Lakes. 
extension of the Carboniferous rocks over the district, and the study 
of the valley-systems of other areas will probably enable us in 
many cases to argue concerning the former extension of beds over 
regions from which they have long since disappeared. 
The duration of the movement which caused the elevation of the 
dome is hard to determine. There is no doubt that elevation had 
taken place before the deposition of the New Red Sandstone deposits 
of Edenside and the Cumbrian coast, for the latter rest unconform- 
ably upon the Lower Paleozoic rocks in places, and the former 
contain fragments of Mountain Limestone, whilst the sandstones were 
probably derived in great part from the deuudation of the Carboni- 
ferous sandstones. In connexion with this point the rarity or 
absence of Lower Paleozoic pebbles in the New Red breccias of 
Edenside is noticeable, and has been commented upon by Mr. 
Goodchild.’ It furnishes another argument in favour of the 
extension of the Carboniferous rocks over the central part of the 
district. But that the elevation was entirely carried on during the 
time that elapsed between Carboniferous and New Red Sandstone 
times is negatived by the dip of the New Red itself, which, as 
observed by Mr. Hopkins and Mr. Goodchild, is sufficient to carry 
these deposits also over the central dome. Now, the north-east 
portion of the Lake District dome coincides with the western margin 
of the New Red basin of Edenside, and was therefore partly 
determined simultaneously with the latter. 
The New Red Sandstones were apparently deposited in a fjord- 
like indentation produced during the deposition of these rocks (a 
point which is well worth working out in detail by any one who 
has carefully studied the characters and distribution of these rocks). 
But there appears to be no important physical break between the 
New Red deposits of Edenside and the lowest Jurassic beds of 
Carlisle. The position of the latter indicates that they also were 
deposited during the continuance of the formation of the basin, and 
there is no reason why these and newer Mesozoic rocks should not 
have once extended over the gradually rising dome of the Lake 
District. If this be so, the valleys of the district need not date back 
to any very remote period, and may even have been commenced in 
Tertiary times. 
§ 4.— Origin of the Dome. 
It has been observed, that although the Lake District dome is a 
continuation westward of an anticlinal axis, it is, nevertheless, in a 
certain sense distinct from this axis. Not only is this the case, but 
it will be noticed, on examining a geological map of England, that 
the dome causes a marked asymmetry in the arrangement of the 
Carboniferous rocks. 
The north and south Pennine axis, and the east and west axis 
separating the coal-field of Yorkshire, Derbyshire, and Nottingham- 
shire from that of Newcastle, and that of South Lancashire and 
North Staffordshire from that of Cumberland, give rise to a cruciform 
1 Trans. Cumb. and West. Assoc. 1885, p. 37. 
