Over the Plain of Cumberland. 567 



ice (unless we feel justified in having recourse to a new order of 

 causes and an entire change in physical conditions), but they have 

 become mutually interwoven to an extent which, I believe, can only 

 be accounted for by ice-laden currents, shifting their direction with 

 the progress of subsidence, and drift-currents variously directed by 

 changing winds. 



The granite of the Criffell and Dalbeattie area, during its dispersion in directions 

 between E. and S.S.E., has been crossed at various, including right-angles, by 

 porphyritic and syenitic drift from the Caldbeck and Carrock Fells, over an area at 

 least twelve miles in breadth. 



Between S.E. and nearly S., Criffell granitic drift has been obliquely crossed, at 

 various angles, by porphyry, trap, etc., from the Caldbeck hills, over the sea-coast 

 area embraced by the granite, as far at least as "Whitehaven. 



Between S.E. and nearly S., Criffell granite, thinly dispersed over the southern 

 part of the above sea-coast area, as far at least as St. Bees, has been extensively 

 crossed, at right-angles and obliquely, by syenite and porphyry from Ennerdale and 

 the neighbourhood. 1 



Porphyry, trap, etc., from the Caldbeck hills, in its south-western dispersion, 

 has been crossed at various angles by syenite and porphyry from the mountains 

 above Crummock and Buttermere waters, and the interior neighbourhood, over 

 an area at least six miles in breadth ; and the same syenitic and porphyritic drift 

 has crossed the granitic drift (already crossed by Caldbeck drift) over an area attain- 

 ing a breadth, on the sea-coast, of at least eight miles, from beyond Maryport to 

 the neighbourhood of Harrington. 



Quadripartite Division of Drifts in Cumberland. — The abruptness 

 with wliich my last article in the Geol. Mag. (Oct., 1870) concluded, 

 may render a few additional notes on this subject necessary. — The 

 drifts of Cumberland are more or less interwoven in vertical as well 

 as horizontal succession. The upper red loamy clay (partly derived 

 from the waste of the Permian strata), as already hinted, contains 

 few boulders, but they are not altogether absent. I saw a large 

 boulder of granite identical with that now quarried near Dalbeattie, 

 in this clay, between Maryport and Flimby ; and, a short distance to 

 the N.W. of Carlisle, near the E. Eden, I saw two boulders of 

 Dalbeattie granite (one of them 5x2x3 feet) in upper boulder-clay, 

 in a railway cutting. Farther N.E., on the opposite bank of the 

 river, a considerable thickness of the upper clay with boulders, may 

 be seen resting on stratified gravel and sand — the latter resting on 

 red sandstone rock. The sand and gravel formation of various parts 

 of the plain of Cumberland (in the neighbourhood of Carlisle, 

 Wetherall, Wigtown, Bullgill station,'^ Lamplugh, St. Bees, etc.,) con- 

 tains pebbles and a few boulders of most, if not all, of the rocks 

 found in the clay above and below. The finest section of sand and 

 gravel, nearly horizontally stratified, I have yet seen in Cumberland, 

 is near Harrington, where it composes a denuded knoll, and attains 



^ I have lately found that limestone drift (including a split-block 10 feet in 

 diameter and of unknown thickness) from the N. orW. has been left on the western 

 slope of Dent Hill, near Cleator, by a current which, at a greater or less angle, must 

 have been crossed by the above-mentioned syenitic and porphyritic drift from Enner- 

 dale, which covers nearly the whole of Dent Hill (Skiddaw Slate) up to the summit, 

 near to which, at 1,100 feet above the sea, there is a boulder, 8x8x5 feet, called 

 Samson's Cobble, or the Finger Stone, consisting of rock midway between porphyry 

 and syenite. 



* Here it forms a plateau, and rests partly on rock and partly on the reddish- 

 brown clay. 



