46 GEOLOGY OF MOOSE RIVER GOLD DISTRICT — WOODMAN. 



the south axis dip 85° N., instead of 82° S., and would not 

 bring the two into their present distance relations. If the south 

 rose, the axes would migrate south, and they did not. Similar 

 objections hold, upon the supposition of a fulcrum south of the 

 field. Thus it appears that no one of the possible classes of 

 movements can account unaided for the present conditions ; and 

 a combination of two or more would fail as surely. 



If, however, the effect is considered of a compression of the 

 folds, acting in conjunction with the faulting, it is found that 

 any one of the four methods is available. But only two are 

 quantitatively probable : — (1) horizontal movement of the east 

 block northward with reference to the other ; and (2) an oblique 

 motion on the east side up and northward, with compression 

 from the south. It is at present impossible to state positively 

 which of the two is correct, because we have not, as in compar- 

 ing divisions ii and iii, definite horizons by which vertical 

 change can be computed. If (2) be accepted, the proportion of 

 oblique motion to compression is hard to determine, because the 

 latter has altered the dip of the axial planes. In the case of (1), 

 the amount of direct sliding of the whole mass depends upon the 

 position in the north anticline of the fulcrum upon which that axis 

 has turned from 60' to 70°. If this fulcrum lay at the present 

 surface of the ground, the east mass as a whole moved north the 

 whole distance of the off"set of the north axis. If the fulcrum 

 lay below the surface, the movement of the whole east block 

 was greater than this ; if above the surface, it Avas less, and 

 may theoretically have been negative, or southward. In any 

 of these cases, compression horizontally accounts for all the 

 motion represented by the diff'erence between the motion of 

 translation and the ofiset of the south anticline. 



But steepening the dip of an axis in the course of compres- 

 sion inevitablj' alters the dip of the strata, on one side adding to 

 the increase of dip of the beds accomplished by the compression 

 itself. The steepening will occur on the side of the fold towards 

 which the axis dips ; and will be least, perhaps almost nothing, 



