Vol. 60.] ROCKS OP THE BORROWJULE VOLCANIC SERIES. 91 



Banded Ashes. Speaking roughly, they form a ring round the 

 highest part of the district. A very typical section of the whole 

 group may be seen on Base Brown, which is entirely composed of 

 them. They run obliquely across Sourmilk-Gill Combe and form 

 the big masses of Great Gable and Green Gable. Lingmell and the 

 stretch of rock from Slight Side to Greencove Wvke on Scawfell 

 are entirely composed of them. They are lost to sight beneath 

 Eskdale Moss, but appear again on Gait Crags and form the rugged 

 and lofty ground stretching from Buscoe Tarns southward to Crinkle 

 (rags and beyond. They probably occupy a considerable area 

 south of Oxendalc, and may extend to the Wry nose Valley. They 

 fill the Langdale Valley to a height of 1000 feet, and run round to 

 Easedale Tarn. Farther I have not traced them. 



From Base Brown they may he followed eastward across the 

 Perwent Valley to Hind Side and the lower slopes of Glaramara. 

 They form the rugged plateau of Bosthwaite Fell, and run obliquely 

 across the lower ends of the Langstrath and Greenup valleys, and 

 occur on the top and slopes of Cold-Barrow Fell above Blea Tarn. 

 Farther east they are absent, and are probably cut off by the north- 

 west to south-east fault mapped by Ward. 



In addition to this regular outcrop, they occur in patches in 

 many districts. They form a great part of Yewbarrow, and at 

 Stirrup Crag is an excellent development of them. They also occur 

 on Illgill Head (Wast water), and on the lower slopes of Helvellyn 

 in the neighbourhood of Whelpside Gill, where a yellow ' streaky ' 

 rock is overlain by a blue flinty ash. 



Although well developed and of great thickness in the central 

 part of the district, they do not occur between the Eycott Lavas 

 and the slate-band in the south. Their absence in this tract of 

 country led Mr. Marr to put them on the same footing as many 

 of the other garnet-bearing rocks of the district, and to suggest 

 that they were intrusive into the Volcanic Series. At first sight 

 there appears to be a good deal of evidence in favour of such an 

 intrusive theory, despite the obviously-fragmental nature of some 

 of the rocks. 



At their upper junction with the Scawfell Banded Ashes there is 

 almost universally a great intermingling of the two rock-types. 

 The banded ash seems to have been absorbed in great quantity, so 

 as to form a complex mosaic of highly-altered, greenish-white, flinty 

 ash and garnet- rock. This is exceedingly well shown on a rock -face, 

 a few yards south of Buscoe Tarns on Bowfell. A good example 

 also occurs immediately south of the gate at the Langstrath Gorge, 

 where a white flinty ash with greenish streaks is caught up by a 

 reddish garnetiferous rock. It is through this complex that the 

 stream has cut so deep a gorge. 



Many intrusive rocks show this phenomenon. On a minor scale 

 the garnet-bearing intrusive rock at Great Crag. Dock Tarn (fig. 3, 

 p. 92), is seen to incorporate the banded ash and form a mosaic. 

 But an excellent example is afforded by the Eskdale Granite just 

 south of Stony Tarn, where the stream from the tarn enters a small 



