QUARTZITE TONGUE AT REPUBLIC. MICH. 



687 



these, surrounded by more or less ferruginous, chloritic and 

 siliceous cement, in which many grains of blue quartz occur. 

 The jasper wedge is not separated from the breccia by any 

 sharp line of division. The layers, which in the solid body of 



Fig. 3. — Sketch plan of the outcrops in the vicinity of the Thompson Pit. A, A = 

 Conglomerate at the base of the main mass of the Upper Marquette Quartzite. 

 B, B = Jasper Wedge. C, C = Quartzite tongue. D, D = Lower Marquette 

 Jasper. E = Thompson Pit. One inch = 50 feet. 



the wedge stand nearly vertical, become contorted near the 

 breccia and bend towards it, the convex side of the little arches 

 being upward on vertical sections and towards the south on the 

 horizontal exposures (Figs. 2 and 3). This indicates that the 

 material west of the fault, towards the interior of the trough 

 moved relatively upwards, and had also a southerly horizontal 

 component. 



