28 J. CLIFTON WARD ON THE GRANITIC, GRANITOID, AND 



Leading Results of the several Parts. — In the four preceding parts 

 of this memoir I have endeavoured to bring forward all the prin- 

 cipal facts bearing upon the origin of the Plutonic rocks of the 

 district, and the degree of alteration to which the surrounding rocks 

 have been subjected. 



In Part I. the evidence of the liquid-cavities in the quartz of the 

 granitic and granitoid rocks was considered, the general conclusion 

 being that the granites, syenitic granites, and quartz felsites were 

 all consolidated at very considerable depths, under great pressure, 

 this pressure being much greater than could be due to the thickness 

 of overlying rocks, and therefore exerted mainly from below and 

 laterally, and resulting in the work of upheaval and contortion of 

 the overlying strata. The period at which the principal formation 

 of these granitic and granitoid rocks took place was considered to 

 be that of the Old Eed; and the work of elevation, consequent on 

 the great surplus of upward and lateral pressure, was accompanied 

 by an enormous denudation of rocks at the surface during the greater 

 part of Old Red times. 



In the subsequent divisions of this memoir, the mode of origin of 

 these various masses was discussed. In Part II. the granites of 

 Eskdale and Shap were dealt with, and it was shown to be at least 

 probable, from evidence gathered in the field, and by microscopic 

 and chemical examination, that these granites had been formed by 

 the extreme metamorphism of rocks of the volcanic series, while at 

 the same time the partially intrusive character of the Shap granite 

 was suggested by various considerations. 



Part III. discussed the origin of the Skiddaw granite from points 

 of view furnished by field, microscopic, and chemical investigation. 

 The gradual transition from unaltered Skiddaw Slate to mica-schist 

 was proved under these three heads, while at the same time the 

 abrupt passage from the mica-schist to the granite appeared to 

 negative the idea of the next step, into granite, necessarily follow- 

 ing in this case. 



In Part IV. the quartz felsite of St. John's and the syenitic 

 granite of Euttermere and Ennerdalc were examined as to their 

 origin ; and there was found to be much evidence in favour of their 

 representing transition beds between the volcanic series and Skiddaw 

 Slates, metamorphosed in situ. 



The interesting rocks of Carrock Fell were then considered, and 

 field, microscopic, and chemical evidence were all thought to lead to 

 the inference that these masses of felsitic, dioritic (?), and hyper- 

 sthenic rocks were due to the metamorphism in situ of the beds 

 forming the lower part of the volcanic series. 



Such, then, are the leading results of this inquiry ; and it now 

 only remains to point out several considerations relating to meta- 

 morphism to which the geological facts of this district seem to lead. 



1. Granite at various dejitlis. — Granite, it appears, may be formed 

 and undergo consolidation at very different depths, and under vary- 

 ing circumstances. If the agents (pressure and moist heat) acting 

 in the formation of granite work tolerably near the surface or 



