ORIGIN OF AMPHIBOLITES OF LAURENTIAN AREA 15 
No. 2. No. 1 0 
(CHEVSS IHL a ain aa is irae ene ar oe Dosalanemp Class, Wile ems. sass oe Salfemane 
Onder R ne aren teeny Grermanarery “OLE Sap vais sie ene 1 ee Gallare 
NAT CUR een, tre oleh cr se ASEM My AMS Tree Ui secant Auvergnase 
Sulloram Ceara he hg ents ANGOSe ay yOUbTANR Al eases ue 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 amphibolite (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 typical igneous 
rocks which have been produced by the solidification of molten 
magmas. 
No. 4 No. 5 No. 6 No. 7 No. 8 
SIO ee eesee 50.00 48.81 50.86 50.73 48.85 
AIO ere, 0.82 0.74 eee: 1.59 2.47 
INIA OK! Voila 4 oo 18.84 16.62 Wo 2 19.99 19.35 
PEAQD ae aslo DG] 17 9-77 BAe) 4.29 
He OMe teste, S SoG TA 2.48 4.66 4.94 
MnO 0.08 O.12 eae 0.05 0.19 
CAO vanciaite 10.65 10.30 TONG 2 8.55 7.98 
Mis Oe: 4.63 8.28 Baws 3.48 2.00 
IO Biineaeine I.18 0.76 0.go 1.89 LOL 
INBAO sehen co. 4.46 Bae 3.89 4.03 5-44 
CO7s: 0.10 0.55 Peete Pee heen 
(Chee 0.10 0.03 Syoitie aie not det. 
Sie iinneaer 0.03 0.06 ene fe: ces 
EOE Rete a eas Gi as ate 0.81 Tee213 
EO Ole erseorais 1.00 0.95 PX ise} On, 0.68 
99.97 99.17 100.22 100.13* 99.36 
* Including BaO 0.27. 
No. 4. Amphibolite resulting from the alteration of limestone— 
Maxwell’s Crossing—Lot 5, Range VI, Township of Glamorgan, 
Ontario. 
No. 5. Dyke cutting limestone—Lot 27, Range VIII, Township 
of Methuen, Ontario. 
No. 6. Gabbro, near Baptism River, Minnesota, U. S. A. (Wads- 
worth, Geol. Survey of Minn., 2, p. 79, 1887). 
