SOUDAN FORMATION. 219 



eastward pitch. These facts are shown bj the accompanying iUustrations. 

 In fig. 8, a vertical section across the extreme western end of the basin, there 

 is shown a narrow synchne with both foot and hanging- walls dipping to the 

 north. In fig. 9 there may be seen horizontal sections through the fourth 

 and sixth levels of the Chandler mine, with position of section shown in 

 fig. 11, indicated byline A-B. From study of this figure in comparison 

 with figs. 8, 10, and 11 we see that farthest west and nearest the surface 

 the sjmcline is narrowest, that as we go down we are compelled to go 

 eastward to follow the base of the ore body (which therefore pitches 

 eastward) and that tlie ore body widens very considerably. 





I-'i-. ] i._\'rriiriil ^eriiou through the Chandler mine along the line A-B ol tig. 9. 



North of the southernmost narrow syncline there is an eastward-pro- 

 jecting tongue of greenstone which indicates a subordinate anticline with a 

 second syncline lying north of it and en dchelon with the southernmost syn- 

 cline. The workings of the mine where they extend to the bottom of the 

 ore deposit (fig. 11) show the conditions which exist there. 



From this section we see that the bottom has not a simple basin shape, 

 but in section from north to south shows several subordinate rolls. These 

 are indicated also by the irregularities of the western foot wall, which, instead 



