276 



MK. W. R. WATT OX THE GEOLOGY [June 1914, 



The second and third of the above-described rock-types have 

 been analysed, and their approximate mineral composition calculated, 

 as follows : — 





I. II. 1 



SiO- 



53-33 58-22 



1-24 -96 



18-09 19-60 



1-53 -59 



9-55 5-19 



•19 



nt. fd. 



•04 



6-02 3-37 



3-92 1-02 



1-57 5-83 



3-72 3-64 



nt. fd. 



•12 -14 



•40 -84 



•58 



nt. fd. 



TiO., 



A1,0 3 



Fe 



FeO 



MnO 



(CoNi)O 



BaO 



CaO 



MgO 



KO 



Na 2 



Li 2 



H,0 at 105° C 



H'O above 105° C. ... 

 P.,0. 



FeS 





Totals 



99-49 100-21 







i 



I. Ordiquhill, biotite-felspar rock, east of Ferny Knovve. 

 II. Ordiquhill, monzonite, west of summit. (E. G. Radley, Anal.) 



I. 



Quartz 7-86 



Albite 30-92 



Anorthite 19'46 



Biotite 15-33 



Diopside 6'96 



Hornblende 8*18 



Hypersthene ... 6 - 10 

 Magnetite, etc. . 4*07 



Total 98-88 



II. 



Quartz 7'68 



Orthoclase 27*80 



Albite 30-91 



Anorthite 11*68 



Biotite 10-82 



Garnet 8'05 



Apatite 1*24 



Titanif erous magnetite , etc . 1 • 60 



Total 99-78 



(d) The Car vie hen G-ranitite. — The rock composing this 

 intrusion is pale gvey, and shows a rude foliation due to the linear 

 arrangement of the constituents, such as the biotite. Although 

 it is used locally for building purposes, the quality of the stone 

 varies greatly — from a hard and durable material to a ' gravel.' 

 The bulk of the rock is seen to consist of quartz, felspar, and 

 biotite, to which a microscopic examination adds garnet, chlorite, 



1 I desire to express my gratitude to the Director of H.M. Geological Survey 

 for permitting these analyses to be carried out in the Survey Laboratories. 



