372 PALEOZOIC ROCKS OF THE HUDSON BAY REGIOX 



In a paper on the Xipissing and Algonia bonndarv. Parks-^ describes 

 the rocks occurring along the Abitibi and Little Abitibi rivers and lists 

 the species of fossils collected along these streams. Some of the species 

 from the latter river indicate a possible Devonian horizon lower than the 

 fossiliferons Devonian along the Abitibi. 



More recently Parks has published a more complete list of the Devo- 

 nian fossils formd along Kwataboahegan Eiver/^ which includes certain 

 species that led him to conclude that the limestones exposed along that 

 river were to be correlated with the lower part of the Onondaga of the 

 New York section. 



Fossils of Devonian age were collected from limestone boulders in the 

 glacial drift along the banks of Xelson Eiver about 20 miles below the 

 Split Lake post of the Hudson Bay Company and 50 miles above the first 

 exposure of Paleozoic rocks farther down the river. The species included 

 Striatopora sp., Chonetes sp., Productella sp., Gypidula near comis, 

 Atrypa missouriensis, A. spinosa, and Spirifer siibvaricosa. Silurian fos- 

 sils were also found in some of the limestone boulders in this localit}\ 

 These fossils would indicate that outliers of Devonian and Silurian rocks 

 were probably present in pre-Pleistocene time in places north and east of 

 the great center of accumulation of the Keewatin ice-sheet. However, no 

 Devonian rocks in place have been reported in this region north of the 

 basin of Albany Eiver. 



STRUCTURE OF THE STRATA 



The Devonian rocks along Abitibi and Moose are more or less imdulat- 

 ing, but have a general dip toward the north at a low angle. In places 

 local folds disturb the prevailing inclination of the strata. One of the 

 most prominent folds is exposed on the west bank of Abitibi Eiver near 

 the middle of Long Eapids. about 55 miles above its mouth, where a 

 rather steep syncline crosses the valley in a nearly east-west direction and 

 carries the Devonian limestone below the bed of the river. A thickness 

 of about 55 feet of Upper Devonian S poj'angifes-heaTing shale is here ex- 

 posed above the level of low water for a distance of several rods. Farther 

 up the same river, in the vicinity of Coral Portage, the lower part of the 

 section is cut by dikes and small stacks of basaltic igneous rock. Similar 

 intrusives occur in sandstones and conglomerates of a lower horizon at 

 the Sextant Eapids, 2 14 miles farther up the river. 



23 W. A. Parks : Ontario Bureau of Mines, vol. viii. pt. 2. 1S99, pp. 1S7 and 1S8. 

 2*W. A. Parks: 13th Kept, of the Bureau of Mines. Ontario. Canada, pt. 1. 1904. j>p. 

 ISO to 191. 



