170 H, A. Nicholson — Oil the Lake District. 



morphosed Skiddaw Slate, overlaid in its higher portion by the same 

 felspathic rock before alluded to. The bedding in the Skiddaw Slates 

 is to a great extent obliterated, but it can be sometimes made out, as 

 near Swineside, where the strike is N.E. and S.W., that of the over- 

 lying trappean rocks being nearly E. and W. In this district, there- 

 fore (from the head of Grainsgill Beck, along the left bank of the 

 Caldew, as far as Mosedale), it will be seen that the base of the 

 Green Slates rests upon the metamorphosed loiver beds of the 

 Skiddaw Slates, which are so well known as occurring in the higher 

 reaches of the Caldew valley. Not only is this so, but the strike of 

 the two formations is entirely at variance. 



This last phenomenon, however, is more strikingly exhibited in 

 the remaining portion of this region, namely between Mosedale and 

 Troutbeck. The range of the Caldbeck Fells, as I have said, runs 

 nearly due E. and W., but this ceases to be the case at Mosedale, 

 where it is deflected in a N.W. and S.E. direction, forming a low 

 ridge of craggy hills, which runs from Murrah to Greenah Crag, 

 about three-quarters of a mile to the north of Troutbeck Station. 

 This range, of which Eycott Hill (1131 feet) is the culminating 

 point, is composed of a beautiful series of bedded traps and ashes,'^ 

 constituting the lower portion of the Green Slate series. In a little 

 stream, which flows from the south-eastern extremity of Eycott Hill, 

 this series is excellently exhibited, and their inclination can be most 

 satisfactorily determined, by means of an ash-bed included between 

 two sheets of trap, to be N.E. at 30°. They strike, therefore, N.W. 

 and S.E. Though the country immediately to the S.W. of Eycott 

 Hill is much obscured by drift,^ and is without any rock-exposure, 

 there can be no doubt but that it is occuj)ied by the Skiddaw Slates. 

 Thus, in the course of GiUs Beck, to the east of Troutbeck Station, 

 the upper shaly beds of the Skiddaw Slates are seen, striking E.N.E. 

 and W.S.W., and dipping N.N.W. at angles of from 50"^ to 60°. The 

 S.W., extremity of Eycott Hill must, therefore, rest upon the uj^per 

 beds of the Skiddaw Slates. Again, at Mungrisedale, about two and 

 a half miles to the north of this point, the Skiddaw Slates are seen 

 in the form of hard, flaggy beds, with a few intercalated bands of 

 grit, and very little aff'ected by cleavage. They are not in any way 

 metamorphosed, and they dip S.S.E. at about 60*^, striking E.N.E. and 

 W.S.W. right against the trappean range of Eycott HiU, which is 



' I may mention that there occurs here a magnificent, porphyritic, and amygda- 

 loidal trap, containing numerous crystals of felspar — some of which are more than 

 half an inch in length — together with numerous cavities filled with calcspar or with 

 chalcedony. It is, without exception, the most beautiful porphyry with which I am 

 acquainted as occurring in the Lake-district. It is a very persistent bed, being seen 

 at various points in the Caldbeck Fells, and occurring at Binsey Crag. At some dis- 

 tance above it, in the same section, there occurs an equally beautiful amygdaloidal ash. 



* It is worth while noticing, in connection with a recent paper by Mr. Maw (Geol. 

 Mag. Vol. VI. p. 72), that the " lower drift," which he there describes as seen at 

 Workington, occurs here, many miles from the coast, and at an elevation of several 

 hundred feet above the sea-level. The section in question (at Greenah Moss) exactly 

 resembles the one described by Mr. Maw, consisting of an inferior, very tough, blue 

 clay, which contains boulders, and is overlaid by a red, loamy drift, containing, in 

 greater abundance, fragments of the rocks of the Lake-district. 



