112 



KEMPS ORE DEPOSITS. 



deed they are not even larger and of a form to be more easily 

 mined. The present developments are situated southwest of Ver- 

 milion Lake, and nearer Duluth and Lake Superior. The ore lies 

 under the black slates called Animikie in the section given in 

 Paragraph 2.02.25, and over the quartzite, there called the Pewa- 

 bic ; but they are situated twenty miles or so west of the line of 

 that section. The ore bodies are all south of the granite ridge 

 called the Giants' range. Upon the southern slopes of this range 

 lie the green schists of the Keewatin, which are unconformably 

 overlain by the Pewabic quartzite. On this rests the ore-bearing 



FIG. 21. General cross section of ore body at Biwabik, Mesabi Range, 

 Minn. After H. V. Winchell, 2Qth Ann. Rep. Minn. State Geologist. 



rock, which is a jaspery quartzite, called taconyte by H. V. Win- 

 chell. Over this, in order, come greenish siliceous slates and 

 cherts, black slates (referred to the Animikie), and great masses of 

 gabbro. On the flanks of the Giants' range the dip is steep, but 

 it flattens out nearly to horizontality away from the granite. All 

 the formations above the Keewatin are called Taconic by the Win- 

 chells. 



2.02.28. The ore bodies lie on the southerly slopes of low hills, 

 and are found immediately below the mantle of glacial drift, which 

 varies up to 100 feet in thickness. Ore indications have long been 

 known on the range, and various reports have been made in previ- 

 ous years, although always unfavorably. The indications ^ 



