52 GEOLOGY OF :M00.SE river gold DLSTRICT — WOODMAN. 



These both show low dips. The displacements of the north anti- 

 clinal and synclinal axes are plotted as intermediate between 

 192.5 feet on the south, and 110 on the north, the amount being- 

 reckoned with reference to the observations farthest north and 

 south. This gives for the anticlinal axis a horizontal displace- 

 ment of 142.5 feet, an offset of 127.5 left, and an overlap of 57.5 

 feet negative. 



East fault : explanation of movements, and present attitude 

 of division iv. — The structure of division iv cannot be explained 

 by either horizontal or vertical sliding, or by shearing, unaided ; 

 for the present relations of the parts, compared with similar ones 

 west of the fault, are not such as should be found after any of 

 these classes of movements. The Little North is in division iv 

 farther from the axis than in the cross-section drawn for divi- 

 sion iii. If the axis continues parallel to the leads eastward to 

 the fault, since the dip of the axis has not changed, it may be 

 fair to consider that the difference in distance has resulted from 

 a vertical movement. This could be made by a rise of 52.5 feet 

 on the east, in this part of the block. But if such were the case, 

 the axis east of the break would now be south of that part to 

 the west, because of its migration down the dip. It is probable, 

 in view especially of the divergence of strikes between the north 

 of the district and the remainder, in divisions iii and iv, that the 

 north anticlinal axis takes an intermediate course, as plotted. 

 On this basis, the north leads are so situated in division iv with 

 reference to the axis, as not to require an upward motion to ex- 

 plain their position. The alternative is a northward horizontal 

 sliding of the whole block to the extent of 129.5 feet, the offset 

 of the fault at the north axis ; and a compression of the north 

 side of the fold to a,n extent of 29.5, measured at the Little 

 North. 



The changed attitude of the southern part of the field in this 

 block, relative to the northern anticline, is such that only a 

 bulging upward could account for it. The northern limit of this 

 movement was at the center of that fold. The action did not 



