46 Reports and Proceedmgs. 



crystals. The junction between the mica-schist and the granite is 

 generally rather abrupt. On the whole, chemical and field evidence 

 especially are against regarding the granite, now exposed, as the 

 result of the extreme metamorphism of the Skiddaw slates imme- 

 diately around it ; but whether it may not have resulted from the 

 metamorphism of underlying parts of the same series is an open 

 question. The great contortion of the mica-schist around the gra- 

 nitic centres may be in part due to the, at any rate, partially intrusive 

 character of the granite. 



In an Appendix abstracts of papers by various authors who have 

 written in connexion with the subject were given. 



Part IV. — (hi the Quartz Felsite, Syenitic, and associated Meta- 

 morpliic Mocks of the Lake-district. 



This part was treated under the same three heads of Field, Micro- 

 scopical, and Chemical evidence as the last. 



The Quartz Felsite of St. John's Vale, and the Syenitic Granite of 

 Buttermere and Ennerdale, lie for the most part at the junction of 

 the volcanic and Skiddaw series, and seem by their line of strike, 

 and by the occasional presence of bands of slate or volcanic rock, 

 enclosed within or running through them, to represent the transition 

 beds between the two series, metamorjDhosed in great measure in situ. 

 Both microscopic and chemical evidence demonstrate the possibility 

 of this process. 



Evidence gathered in the field, and microscopic and chemical 

 examination, all seem to suggest that the rocks of Carrock Fell, etc., 

 represent the base of the volcanic series, consisting largely of con- 

 temporaneous traps, thrown into a synclinal, the axis of which 

 ranges generally east and west, and metamorphosed into rocks of 

 greatly varying character, such as sphserolitic felsite, hypersthenite, 

 and diorite. 



Although all the various masses treated of were probably formed 

 in the main by the metamorphism of beds in situ, it is probable that 

 some parts of the resulting magma became occasionally intrusive 

 among and absorptive of higher beds. 



In an Appendix notices of papers on these rocks by other authors 

 were given. 



Part V. — General Summary. 



In this part the leading results of the four preceding divisions of 

 this memoir were briefly brought forward, followed by the discussion 

 of various considerations relating to metamorphism, under the fol- 

 lowing heads : — (1) Granite at various depths : (2) how far granite 

 may be an ultimate universal product of metamorphism ; (3) dis- 

 tribution of metamorphism (selective metamorphism) ; (4) classes 

 of metamorphism. 



The paper was illustrated by a large geological map of the 

 northern part of the Lake-district, by a geological model of the 

 Keswick district, by rock specimens, and large coloured photographs 

 taken from water-colour microscopic drawings made by the author. 



