THE SHAP GK\N1TE AND ASSOCIATED BOCKS. 291 



and to the Cross Fell, Sedbergh, and Ligleton areas, and do not 

 occur around the Eskdalo granite, though the minette of Bale Fell and 

 the mica-traps of Dodd are near the granite of Skiddaw. Both the 

 felsitic and micaceous rocks have abundant porphyritic felspars in 

 the neighbourhood of the Shap granite, as we have shown in our 

 description of the rocks from Stakeley Folds and elsewhere, and 

 these fcls23ar8 are in every respect so similar to those of the granite 

 itself that it seems impossible to disconnect them from that mass, 

 especially as we find that the felspars abound near the granite 

 contact, and become rarer as we recede from this, whilst at the 

 same time the more distant dykes show other indications of having 

 consolidated at a greater distance from the then deep-seated magma, 

 as evidenced by the occurrence of vesicles in the dyke at Castle How, 

 near Tebay, which contains few porphyritic crystals. We have 

 already pointed out the resemblances between these dykes and sills 

 and the dark patches included in the granite. It would seem that a 

 magma occurred beneath the Shap granite of a more basic character 

 than the granite itself, and that from this the micaceous dykes 

 were sent out, whilst the more acid portion of the magma was 

 injected into rocks at a higher level than the main source of supply 

 to form the Shap granite and the felsite apophyses, portions of the 

 more basic part being carried up as " clots " in the granite, consti- 

 tuting the dark patches contained therein. In favour of this view, we 

 may note that the evidence points to the Shap granite and the mica- 

 traps having been formed at the same geological period, as shown 

 by the intrusion of undoubted apophyses of the granite along with 

 mica-traps in rocks of late Silurian age, whilst the pre-Carboni- 

 ferous age of both the granite and the mica-traps is generally 

 recognized. From the great abundance of mica-trap dykes it is 

 evident that a magma like that which we suppose to have existed at 

 a lower level than the Shap granite must have been situated 

 at some point below this region, and the strong resemblance of the 

 micaceous dykes of Stakeley Folds and the Gill to the patches in 

 the granite almost certainly demonstrates that they have had a 

 common source. 



The possible presence of this more extensive magma underneath 

 the Shap granite, and at one time connected with it, is of great 

 importance in discussing the origin of the actual granite mass. 

 In connexion with the foregoing observations, a few remarks 

 concerning the nature of the intrusive mass of Shap seem to be 

 necessary, though, in the absence of any certain knowledge, our 

 comments must be brief. 



We have attempted to show that the Shap granite is merely 

 a subsidiary offshoot of a deep-seated igneous mass of much greater 

 extent. It is interesting to observe that just as the Shap granite 

 occurs at the point of contact of two sets of disturbances, viz. that 

 which has produced the normal strike of the Lake District rocks, 

 and that which gives the beds associated with the Skiddaw Slates to 

 the west of the village of Shap a general N.W.-S.E. strike, so the 

 principal dykes which we have attempted to connect with the 



