70 



Orthoclase . . 



Albite 



Anorthite . . . 

 Nepheline . . . 



Sodalite 



Diopside 

 Akermanite . 



Olivine 



Calcite 



Ilmenite. . . . 

 Magnetite.. . 

 Pyrite 



Water. 



No. 2. 



7-23 



26-20 



27-94 

 5-56 

 0-42 



19-78 



6-30 



0-20 



i-52 

 3-7i 

 0-04 



98-90 

 I -oo 



99-90 



No. 1 (b) 



7-74 

 15-24 

 25-59 





34 



81 



6 



97 



4 



85 



1 



40 



1 



80 



)8-40 

 1-66 



100-06 



In the quantitative classification the rocks, therefore, 

 have the following position : — 



No. 2. 



Class II Dosalane 



Order 5 Germanare 



Rang 3 Andase 



Sub-rang 4 Andose 



NO. 1 b. 



Class III Salfemane 



Order 5 Gallare 



Rang 4 Auvergnase 



Subrang 4 Auvergnose 



While, therefore, the quantitative classification is 

 intended to apply only to igneous rocks, this final product 

 of the metamorphism of the limestone when compared with 

 igneous rocks readily takes its place as an andose, a group 

 which includes many rocks which are commonly known as 

 diorites, gabbros, basalts, diabases and essexites. 



For purposes of comparison the analysis of this amphi- 

 bolite (No. 2) is here repeated together with that of an 

 amphibolite (No. 5) produced by the alteration of a basic 

 igneous intrusion (probably a diabase originally) and with 

 the analyses of three other typical igneous rocks which 

 have been produced by the solidification of molten magmas. 



