492 C. E. De Ranee — Surface Geology of the Lake-district. 



he accurately describes as being, "not only the most precipitous, 

 but indented with voes separated by edges, one of the voes termi- 

 nating in Eed Tarn Cwm." I have not the 6-inch ordnance maps 

 of this district, but from a rough observation I made, when des- 

 cending the precipitous slope described by Mr. Mackintosh, believe 

 the base is about 860 feet below the apex of Helvellyn, dipping at 

 an angle of from 40° to 60° ; on the Catchedecam side the angle is 

 rather less, on Striding Edge rather more. From the bottom of the 

 precipice to Ked Tarn is a gradual slope of perhaps 50 feet. 

 Through the centre of this slope, flows Eed Tarn Beck, the first 

 commencement of which is found in a small pond of running water 

 immediately below the precipice, fed by a number of springs, 

 issuing from the base of the cliff. The water, notwithstanding the 

 great heat of the weather at the time of my visit (August), was intensely 

 cold. From the dryness of the season, the lake Ked Tarn was 

 empty, and I therefore had an opportunity of examining its bottom. 

 The banks consist of angular fragments, derived from the mountain 

 above, none seemed to have experienced ice or glacier action, and 

 most certainly there was no sign of the sea, neither a rounded 

 pebble, or a single foreign fragment. The bottom of the Tarn was 

 composed of fine sand brought by the springs out of the mountain ; 

 the banks of fragments, torn off its slopes by frosts and landslips. 

 The sub-aerial dejjosit in which this lake occurs, appears to have 

 choked up the bottom of the gorge under the mountain to a con- 

 siderable depth, but following Eed Tarn Beck, down the valley 

 towards Ulleswater, the beck cuts down to rock, which is here and 

 there glaciated. If the sea formed the two voes on either side of 

 Striding edge, it is difficult to understand why it did not destroy the 

 edge itself, especially as we know that the sea destroys headlands at 

 the same and even " quicker rates than it works back lowlands." 

 Though I agree with Mr. Mackintosh, " that, in those river gulleys 

 which graduate upwards into larger valleys we may often discover 

 a sufficient distinction between their respective contours to justify 

 our referring the one to fluviatile, and the other to marine denuda- 

 tion " (p. 303), as applied to some districts, yet I think such 

 hollows of undulation in the original surface of marine denudation, 

 in the lake district, are of extreme shallowness, and play altogether 

 a secondary and unimportant part in the physical features of the 

 country. Nor does it appear that the higher portion of this 

 mountainous district was ever beneath the Glacial sea. From the 

 shortness of the time I spent in the Lake-district, I was not able to 

 make out the height to which it reached, but the rocks did not appear 

 to be glaciated above a level of about 1,700 feet above the sea, the 

 glaciation down to about 400 feet above sea level appearing to have 

 been caused rather by land ice than by the grounding of ice-bergs. 

 In the low country of Furness, the same sequence of upper and 

 lower Boulder-clays, divided by a middle sand and gravel, occurs 

 as was described by Mr. Hull, F.K.S., in 1863, as occurring in the 

 Manchester district ;^ which classification has been adopted by Mr. 



^ Additional Observations on the Drift Deposits, etc. Mem. Lit. PhU.. Society, 

 vol. it,, 3rd series. Geol. Sur. Mem., on Qr. Sh., 88, S.W. 



