IRON ORES 



345 



the outlines of the workings which are reduced from the surveys 

 of Mr McKee, the engineer of the two companies, gives a 

 clearer idea of the relations in plan than any description could 

 and also of the surface topography. The sections will further 

 afford a picture of the relation in elevation. They have been 

 compiled from the most recent mine surveys (1S93), but aid has 

 been obtained from the drawings of Mr. Putnam (10th 'Census, 

 v. 10, plate 27, p. 10S) and. from personal notes on the surface and 

 underground. The important structural features are these : The 

 westerly dip of the north ends of Welch shaft and Miller beds ; the 

 flat and more southerly dip of the Old Bed, of its several divisions 

 and of the Miller; the southerly and easterly dip of " 21." These 

 facts indicate an anticline with a doming development in the east- 

 erly extension of " 21." The forking of the bed makes it possible to 

 have several of them one over the other. The Bonanza-Joker bed 

 lies not far from the axis of this anticline on its southerly pitching 

 crest, as does also Old Bed. The general southwest and somewhat 

 parallel arrangement of all the beds or lenses is strongly shown in the 

 map. Before the folding took place they doubtless all formed hori- 

 zontal and parallel-tending, pod-shaped masses, and were afterwards 

 heaved into their present position with some attendant faulting. The 

 wall rock of " 21," and some distance from the pit, is a light colored 

 gneiss, consisting of microperthitic orthoclase, green augite, a little 

 quartz and magnetite. The same rock also forms the summit of Bar- 

 ton Hill. It may be mentioned that the usual gneiss of the oldest 

 formation contains biotite and some quartz but near the ores it 

 becomes augitic. Microperthite is present in both. The strike of 

 the gneiss is very irregular. Between the Miller Pit and Barton 

 Hill readings were obtained varying from X. 10 E. to X. 85 E. with 

 in one case X GO W. The general average is about northeast. 

 Section CC is drawn nearly across this strike. As indicated in the 

 section the dip toward the Miller Pit is westerly but it changes to 

 easterly and again toward the Barton Hill to the normal westerly. 



In variety of minerals the mines are not prolific. Many years 

 ago James Hall obtained from the Old Bed (called also the Sanford 

 Bed) an unusually fine crystal of allanite which has been figured 

 and described by E. S. Dana, ( Amer. Jour. Sci. June 1SS4. 479). 



In the office of Witherbee, Sherman & Co., at Mineville, there 



