300 J. P. Kimball on Iron Ores of Marquette, Michigan. 
iron ore, vary in thickness from a hair’s breadth to an inch, pro- 
ducing a banded appearance. The fact that the entire mass is 
highly contorted into minute as well as sizeable folds, furnishes 
an explanation of a power of resistance to vicissitudes of erosion, 
superadded to the same property which it derives from the mere 
presence of intermingled jaspery bands. he conglomeratic 
beds of specular iron ore and jasper, are generally preserved in 
elevated outliers, acquiring a refractory character from thei 
coarse and tenacious structure, but I have met with no instance 
of the preservation of the anticlinal crest in beds of this de- 
scription. 
In Section 26, T. 47 N., R. 27 W., an example of a preserved 
anticlinal crest occurs in a ridge of half a mile in length and 170 
feet in height. The specular iron-ore at the surface displays a 
laminated and contorted structure into which enter thin lamine 
of quartz, and although the mass in itself is not so substantial as 
the exterior of the Cleveland Knob, its attending conditions of 
deposit impart to it similar refractory properties. In this region, 
as elsewhere, denudation may be noticed to have had less eliect 
upon those stratified rocks which present to its agencies their 
planes of stratification, than upon those which are highly nelined. 
Hence it wiil be observed that the more extensive the sweep 
the undulations the more complete is the preservation of the 
specular iron-ore which in the form of schists enters into them. 
The most conclusive indications of the stratigraphical condi- 
tions which prevail among the hematite schists in Marquette 
county up to this time exhibited, are disclosed by the cutting a 4 
the Peninsula Railroad in the N.E. quarter of Section 8, T. 4 
N., R. 26 W., to which allusion was made in the first part of th 
article. The grade of the railroad has been laid in an excav® 
tion 600 feet long and sunk 25 feet below the highest point upon 
the surface of a hill which derives its configuration from @ boss 
of hematite schists intercalated with argillite. Thus the cutting 
presents an anticlinal section, as seen in the accompanying We 
cut. The lower strata penetrated are preserved in an unImpal’™ 
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peculiar greenish slates, already described, both becoming ay 
lly reduced in an ascending order from comparatively The 
