The deposits of the useful minerals & rocks; their origin, form, and content . character, so 1 Ante, pp. 314, 315. THE METASOMATIC GOLD DEPOSITS 639 that it easily crumbles and covers the floor of the working. The beds areonly in places horizontal; more usually they form flat anticlines andsynclines. In greater detail the circumstances of their bedding are illus- S/ate -^ii^v . Dolomite- ?;-^*jjI,?-;•.;?.•..•;.•.• •.•.?;•-+ * r^°0lfj,^^^ +vl,*+*+ >•??? •.• • Dolomite .; ; .^t: +^+V4- ci- i^*r; • :•.:?? ? •?? ?.?:? .\-r^-^A*:^-* Fig. 327.—Section showing the geological position of
The deposits of the useful minerals & rocks; their origin, form, and content . character, so 1 Ante, pp. 314, 315. THE METASOMATIC GOLD DEPOSITS 639 that it easily crumbles and covers the floor of the working. The beds areonly in places horizontal; more usually they form flat anticlines andsynclines. In greater detail the circumstances of their bedding are illus- S/ate -^ii^v . Dolomite- ?;-^*jjI,?-;•.;?.•..•;.•.• •.•.?;•-+ * r^°0lfj,^^^ +vl,*+*+ >•??? •.• • Dolomite .; ; .^t: +^+V4- ci- i^*r; • :•.:?? ? •?? ?.?:? .\-r^-^A*:^-* Fig. 327.—Section showing the geological position of the auriferous quartz bed and the trap sheetsin the Malmani dolomite, Lydenburg. Krause, Zeit. f. prakt. Geo!., 1897, Fig. 8. trated in Figs. 327 and 328. In only one case, that illustrated in theabove-mentioned Fig. 328, did Krause observe them to be intruded byan eruptive. The dyke in that case dragged the auriferous material rightto surface with it, indicating that it was younger than the deposit. It Dolomite :. Fig. 328.—Section in the New Clewer Estate mine, Lydenburg. A diabase dyke crosses thequartz bed ; both the quartz and trap extend along the dyke. Krause, Zeif. f. prakt. Geol.,1897, Fig. 9. is characteristic of these quartz beds that they do not always keep to thesame horizon. The payable thickness is 0-15-0-70 m., or on an average040 m., with an average gold content of 30 grm. per ton. Some copperaccompanies the gold. Voit considers rightly that these are metasomatic occurrences andrepresent certain limestone bands which have become altered to present therefore in all probability the rare case of a typicallymetasomatic gold deposit formed from limestone. The occurrence at the Csetatye near Verespatak, mentioned when 640 OKE-DEPOSITS describing the young gold-silver lodes, also belongs to the metasomatic occur-renpes.^ In view of the former description, only those criteria will here bementioned which are indicative of t
Size: 2083px × 1199px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectminesandmineralresou
