350 THE AZOIC SYSTEM AND ITS SUBDIVISIONS. 



junction of the Laiirentian and Iluronian in the Hudson's Bay district, 

 says : — 



" The junction of the two formations, which appear as usiial to be 'conform- 

 able with each other, occurs just where the southwest area opens into the main 

 body of the lake. Here the last of the Laurentian series consists of gray coarse 

 rough-surfaced quartz and mica-rock. The first rock on what is considered to 

 be the Huronian side of the boundary between the two series, consists of highly 

 crystalline dark green hornblende schist, ribboned with fine lines of white 

 qiiartz grains. It is identical in character with the hornblende schist which 

 is usually found at the base of the Huronian bands in the region to the north- 

 westward of Lake Superior." {I. c, 21, C C.) 



It is now necessary to retrace our steps, and give some attention to 

 the Hastings or Montalban series in Canada. To these ]\Ir. Murray 

 called attention in the Report of Pi'ogress for 1852-53, remarking : — 



" In Huntingdon, Madoc, Marmora and Belmont, many interesting diversi- 

 ties occur in the Laurentian series, but the rocks belonging to it become so fre- 

 quently and unexpectedly covered up by projecting and outlying masses of the 

 unconformable fossiliferous formations, in the part investigated, that it is as 

 yet impossible to give any connected view of their arrangement." {I. c, 

 pp. 103-108.) 



In the Pteport of 1863 the rocks were again described (pp. 32, 33), 

 Dr. Hunt giving analyses of the limestone, as belonging to the Lauren- 

 tian (pp. 592, 593). 



In the Pieport for 1866 (pp. 91-113), the Hastings series was once 

 more discussed by Mr. Thomas Macfarlane, who states that in the pre- 

 vious reports they have been shown to belong to the Laurentian. He 

 remarks that some of the conglomerates are " lithologically not unlike 

 some of the Huronian rocks," but does not appear to have taken ground 

 that this series of rocks was newer than the Laurentian, as Dr. Hunt 

 says he (Macfarlane) did (Azoic Rocks, p. 170). In the same Report 

 Logan stated that these rocks appeared to be conformable with the 

 Laurentian series, although they might be a higher portion of the series 

 than had been met with elsewhere. (L c, p. 93.) 



In 1867 Dr. Hunt stated that the Hastings series reposed in concord- 

 ant stratification upon the Laurentian gneiss ; but that the Upper 

 Laurentian or Labradorian reposed unconformably, not only on the 

 Lower Laurentian, but also upon the Hastings series. (Esquisse Geolo- 

 gique du Canada, pp. 5, 6). The same year Logan held that the "inter- 

 ruption " of a limestone zone in the Hastings series by a labradorite 

 rock (gabbro, norite), supposed to be Upper Laurentian, showed that 



