382 THE CRYSTAL FALLS lEON-BEARUSTG DISTRICT. 



beds, with interlaminated thinner ledges and schistose seams, amounting to consider- 

 able thickness. 



Above this belt an equally large succession of well-laminated, even-bedded, often 

 fissile, slate like micaceous quartz-schists follow, which have a silvery luster. Next 

 above them comes a series of micaceous argillites, amounting to a belt even larger 

 than the former, which varies greatly in shades of color, firmness of grain, etc.; some 

 layers are whitish, others gray or bluish and greenish, but the greatest portion of 

 them is intensely red colored by hematitic pigment. A part is a fatty, impalpably 

 fine mass of silky or also pearly luster, according to the size of the mica shales 

 incorporated with them. Another part is rough and gritty from the prevalence of 

 arenaceous constituents. 



At this horizon and rather in the lower part of it occur locally large bodies of 

 crystalline limestone ledges, some snowy white like Italian marble, but of coarser crys- 

 talline grain and intermingled with radiating clusters of asbestine fibers and larger 

 prismatic crystals of colorless tiemolite, which sometimes forms larger concretionary 

 seams in the lime rock, and are then intimately associated with crystal masses of 

 sahlite, one mineral penetrating the other in a manner which suggests either a process 

 of paramorphosis in i^rogress, changing the sahlite into tremolite, or the original 

 conditions, when the calcareous material combined with the silica by a slight modifi- 

 cation, induced simultaneously the crystallization of the almost identical chemical 

 combinations in one and the other form ; which latter suggestion is more sustained 

 by the actual condition of the mingled minerals than the first, as some of the crystals 

 of both minerals tightly grown together are so perfect in form peculiar to each and so 

 sharply defined that they must be considered as crystal individuals which formed side 

 by side and altogether independent of one another. In other localities where such 

 crystalline limestone belts occur, the tremolite is only sparingly intermingled, but in 

 its place colorless mica scales of nacreous luster are plentifully disseminated. 



In the i)lace of marble-like limestone, sometimes also ordinary lime rock of dull 

 aspect with conchoidal fracture, and variously tinged, occurs; it is then usually full 

 of flinty siliceous seams, resembling the limestones of the Quinnesec range; the 

 quartzose seams, locally even, prevail over the calcareous. Incumbent on the above- 

 mentioned micaceous argellites succeeds a belt, about 800 feet in width, composed of 

 thinly laminated, banded, ferruginous, quartzite ledges of dark purplish tints or hav- 

 ing a metallic luster from intermixture of specular ore granules. The banded portions 

 are formed of an alternation of narrow seams of specular ore with siliceous seams not 

 so richly Impregnated with the opde. Other strata in the succession are porous 

 cherty rocks charged with ochreous yellow or brown oxide of iron and inclosing pockets 

 of the limonitic ore. Also blood-red argillitic seams occur in the succession, and with 

 them sometimes pockets of soft crumbly hematite ore. 



Within the first-mentioned banded alternation of narrow ore seams with quartz 

 seams, larger deposits of specular ore in slaty or in compact granular, or also in the 

 soft friable condition of the so-called blue ore of the Quinnesec mines occur, which 

 constitute the principal storage of ore sought for by the miner, besides the hematitic 

 and limonitic deposits mentioned before. The first impression of every observer exam- 

 ining this above described rock series will induce him to consider it as an ascending 

 succession, as the layers follow one another in apparent conformity; but in some local- 

 ites, after having crossed this succession so far, if we proceed farther in the same 



