4 i2 REVIEWS 



Only two divisions of the Huronian are admitted, and the Animikie 

 and Keweenawan are not grouped with the Archean but with the Paleo- 

 zoics. However, these two divisions are associated under the higher 

 name Algonkian. He also proposes the name Ontarian to cover the 

 closely associated Keewatin and Coutchiching. 



The major part of the report is given to a detailed discussion and 

 description of the criteria whereby the Coutchiching is represented to be 

 older than the Keewatin. The arguments presented are based upon 

 structural relations, and actual contacts at which the Keewatin lies 

 upon the Coutchiching. 



The conglomerate which Lawson formerly thought part of the 

 Coutchiching, and which others used to show that the Coutchiching 

 is younger than the Keewatin, Lawson now distinguishes as part of 

 another, very much younger, group, the Seine series. The stratigraphical 

 position of this series is hot clearly established, and therefore the upper 

 part of his Archean classification is not much more than tentative. 



T. T. Q. 



The Pre-Cambrian Geology of Southeastern Ontario. By Willet G. 



Miller and Cyril W. Knight. Report of the Bureau of 



Mines, Vol. XXII, Part II, 1914. Pp. 151, illustrations 67, 



portraits 4, maps 13. 



The chief results of the work were to show that: (1) the sedimentary 



rocks have a basement of Keewatin green schists and ellipsoidal lavas; 



(2) the Grenville series were deposited upon the Keewatin lavas, but 



no erosional interval has been proved; (3) granites of two ages have been 



recognized; the older one is gneissoid and intrudes the Keewatin and 



Grenville rocks, the younger granite intrudes all the local pre-Cambrian 



rocks; (4) most of the metamorphosed blue limestones are classed with 



the Grenville series, but the conglomerates and some other sediments 



are younger and differentiated as the Hastings series; (5) post-Hastings 



igneous rocks are gabbro, basalt, and tuffs, and the Algoman granite 



which is later than the gabbro group. 



Because the great Grenville limestone series (94,000 feet thick — 

 Adams) was pre-Laurentian, the authors think there is no special sig- 

 nificance to be attached to the Laurentian as an epoch-marking time. 

 They drop the terms Algonkian and Archean, and Proterozoic and 

 Archeozoic. They do not reach definite conclusions about the correla- 

 tion of the limestone conglomerate and other formations in the Madoc 

 area. 



