. The Quarterly journal of the Geological Society of London. obviously-fragmental nature of someof the rocks. At their upper junction with the Scawfell Banded Ashes there isalmost universally a great intermingling of the two banded ash seems to have been absorbed in great quantity, soas to form a complex mosaic of highly-altered, greenish-white, flintyash and garnet-rock. This is exceedingly well shown on a rock-face,a few yards south of Buscoe Tarns on Bowfell. A good examplealso occurs immediately south of the gate at the Langstrath Gorge,where a white flinty ash with greenish
. The Quarterly journal of the Geological Society of London. obviously-fragmental nature of someof the rocks. At their upper junction with the Scawfell Banded Ashes there isalmost universally a great intermingling of the two banded ash seems to have been absorbed in great quantity, soas to form a complex mosaic of highly-altered, greenish-white, flintyash and garnet-rock. This is exceedingly well shown on a rock-face,a few yards south of Buscoe Tarns on Bowfell. A good examplealso occurs immediately south of the gate at the Langstrath Gorge,where a white flinty ash with greenish streaks is caught up by areddish garnetiferous rock. It is through this complex that thestream has cut so deep a gorge. Many intrusive rocks show this phenomenon. On a minor scalethe garnet-bearing intrusive rock at Great Crag. Dock Tarn (fig. 3,p. 92), is seen to incorporate the banded ash and form a an excellent example is afforded by the Eskdale Granite justsouth of Stony Tarn, where the stream from the tarn enters a small g o6 jo < I ch. Vol. 60.] ROCKS OF THE BORROWDALE VOLCANIC SERIES. 93 ravine. A similar mosaic occurs in Sourmilk Gill, opposite Sea-thwaite Farm, where the rocks round the graphite-lode arc intrusiveinto banded ash. It would be impossible to conclude from the sections at BuscoeTarns and on Aaron Crags, Seathwaite Fell, that the garnet-rockis intrusive. The appearances would be better explained on thesupposition that the flinty ash was the intrusive rock. Thisintermingling at the junction between the two rocks has beencaused by intense pressure. The bedding-plane between thesoft Banded Ashes and the harder garnet-bearing rocks hasvery probably been one of lag-faulting ; the pressure has beenso great that the ash has been altered and incorporated with thegarnet-rock. An excellent section about 1500 feet up, almost due west of theLangstrath Gorge, illustrates this action. To the north the streaksare seen to dip southward, at an angle varying b
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectgeology, bookyear1845
