File:Transactions (1895) (14780844144).jpg

Identifier: transactions14cana (find matches)
Title: Transactions
Year: 1895 (1890s)
Authors: Canadian Institute of Mining and Metallurgy
Subjects: Mineral industries Mines and mineral resources
Publisher: Montreal (etc.)
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: University of Toronto

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a remarkabb preservation of the stratification of the coun-try rock. As is usual in sulphide ores this banding is less easilyob.served and less perfect than in replacement by silica; but itscontinuity with the bands in the adjoining rock is striking. Theseore bodies are thus described by Boutwell:^ As we stated in the description of the structure of the copper chutes(p. 155), the broad characteristic of this structure is bandinp. This bandingis not likf» thr« cru.-tifiod or even the roughly banded structure of the lodes,but in • iK wiiifli in form is identical witii the bedding of strata. The chief (i is in composition, these beds being composed of ore instead of limc.-fone or fjuartzitc. IJcddcd structure characterizes ahke miniatureore IxxJies, mincruhzed wall rock adjacent to .seams, and large lenticular oreshoots. Thas mineralization adjacent to fissures in limestone took place » 8. F. Emmoiw, T.A.I.M.E., Vol. XXIII, p. G02.» Boutwell. U. S. G, S., Prof, paper No 3S, p, 193.
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i-M C vc 440 Replacement Ore-Bodies—Irving along Ix^ds. Further, the marked deposition of ore along certain beds, andthe slight deposition along others, appear to indicate a selective tendencyon the part of minen\l in solution for more soluble beds. Similarly, in smallshoots the massive structure is a bedding of massive ore, which is more ex-tensive in some beds than in others. Finally, the immense lenses of cupri-ferous pyrite, e.g., those in the Highland Boy, exhibit the same massivebedded structure. This selective action leads to a very irregular periphery.The transition from massive, solid ore to barren country on the peripheryis not sharp, as in the case of the lodes, where the transition from the rich bandsto barren wall rcok is well defined. On the contrary, it is gradual, passingfrom the bed of rich copper sulphide through lean copper ore, still poorer ore,merely stained country, to normal, barren, marble country. Although thecomposition changes from ore to barren country ro

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