SOUDAN FOEMATION. 211 



form an elljow, having' a radius of from 2 to 4 inches, giving- a roundish 

 surface on top, looking like cross sections through a set of closely laid 

 pipes. The minor folds at this exposure pitch to the west at angles A^arying 

 greatly, but ranging mostly between 50'' and 30°. 



The intricate infolding of the green schists and jaspers may be 

 observed at numerous places on Lee and Tower hills, just north of the 

 town of Tower. A study of these will impress one with the extraordinary 

 complexity of this folding. Not only are the dips substantially vertical, 

 but the pitches of the folds are vertical, or nearly so. The result of this is 

 that where the g-reen schist and the jasper come together the contact is 

 most extraordinarily complex. It runs in and out, and in places the jasper 

 might be su2)posed to be over the green schist; in other places the re Averse 

 seems to be the case; and in still other instances one is strongly inclined 

 to believe that one of them cuts the other as an intrusive. In some 

 places there is brecciation along- the contact, so that between the green schist 

 and jasper there is an intervening zone of pseudo-conglomerates. One of 

 these conglomerates has a green schist matrix in which are bedded numerous 

 fragments of banded jasper. Some fragments are well rounded, others 

 subangular, others have curious points, and a considerable number are in 

 roughly rhomboidal form (PL VI, C). The schistosity extends roughly 

 east and west. It cuts the schist, but usually stops abruptly at the jasper 

 bands. This adds still another feature to the complexity of the structure 

 at the contacts. However, although one may be confused by examining 

 the details of some of these exposures, if one follows the broad distribution, 

 he will find in many places that the schist and jasper occur in belts which 

 can be separated as such, the major folds being made out in many cases. 



One of the largest exposures of jasper in the Vermilion district is that 

 which forms tlie prominent peak known very commonly as Jasper Peak, 

 although the name Chester Peak has prior claim. The jasper is exposed 

 over almost the entire area of the hill. The outcrops, while not solid, are 

 nevertheless so numerous as to enable one to determine very easily the 

 structural features. The south side of the hill is nearly vertical, and gives 

 very good sections through the intricately folded iron formation. A study 

 of the hill shows that the iron formation is folded into a great synclinorium 

 made up of a number of closely folded synclines and anticlines. The gen- 

 eral strike of the axis of the synclinorium is N. 60° E., and the axis plunges 

 to the east, though the exact angle is not known. 



