GEOLOGY OF THE PHILIPS BURG REGION OF QUEBEC 317 



international boundary into Quebec to Philipsburg two miles 

 beyond. From Philipsburg the strike, which maintains a north- 

 easterly direction, carries us away from the lake. In this direction 

 the series can be traced through Morgan's Corners (formerly Blood's 

 Corners) to the village of Bedford, where higher strata come in, 

 and beyond to Mystic. The northernmost outcrop of the highest 

 bed which is traceable, occurs about two miles north of Mystic 

 on the twenty-second lot of range six, Stanbridge, Quebec. 



Using this outcrop as an arbitrary northern limit of the series, 

 the area under discussion is roughly fifteen miles long. The width 

 varies from about a mile and a half on the south and north to about 

 three and a half miles in the middle. On the east, west, and south 

 the section is truncated by faults. To the north the prevailing 

 limestone gives way to slates whose structure and stratigraphy 

 are as yet very little understood. 



In 1863 the intricacies of the geology of the Philipsburg region 

 were made known by Logan in his admirable report on the geology 

 of Canada.^ This work was done in great detail and with great 

 accuracy. The general division of the section into four parts on 

 the basis of lithology seems a good one for the sake of discussion, 

 and in this paper the writer will adhere to Logan's Divisions A, B, C, 

 and D. It must be remembered, however, that these divisions, 

 although marked lithologic units, are not necessarily stratigraphic 

 or structural units. This fact will be made clearer in the subsequent 

 discussion. Logan's section, in descending order, is briefly as follows : 



D 



Feet 



3. Grey and black striped slates interstratified with thin beds of black 



limestone and limestone conglomerate 1,500 



2. Black and greenish argillaceous slates with patches of limestone 



conglomerate and bands of magnesian slates 1,000 



1. Black limestone conglomerates, composed chiefly of the ruins of thick 

 bedded limestones of division C 300 



2,800 

 C 



2. Black slates and thin-bedded black limestones, toward the top 

 imperfectly seen 170 



I. Black and dark grey compact pure massive limestones with a few 



bands of dove grey 150 



• ■ 320 



^ Sir Wilham Logan, Geology of Canada, 1863, pp. 175-280; 844-54. 



