Bulletin Volume 722 - Geological Survey, Paperback

• Release Date   5/19/2012
• ISBN-13   9781236196170 | 978-1-236-19617-0
• ISBN   1236196171 | 1-236-19617-1
• Format   Paperback
• Author(s)   Geological Survey
• This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1922 Excerpt: ...the lower workings. The shaft was 76 feet deep when visited, and there was about 70 feet of drift. At the surface the ore is the full width of the shaft, which does not show the walls. At the bottom of the shaft the vein is not more than 4 feet wide. The ore, which is thoroughly oxidized, consists of chloritic material, iron ores, and quartz with many thin films and small masses of malachite and azurite. Whalen shaft.--The Whalen shaft is on the divide between Ruby and Hidden creeks. At the end of August, 1920, it was 100 feet deep, and there was 160 feet of drift on the 40-foot level. Crosscuts on the 40-foot level show 32 feet of ore reported to average $68 per ton in gold. The vein is in limestone not far from the monzonite, and at the south end of the workings it lies very close to the monzonite. The ore, which is thoroughly oxidized even in the deepest workings, consists of chloritic material, iron ores, and quartz, containing many small masses of copner carbonates and a few small masses of chalcopyrite or pyrite. Garnet trench.--The Garnet trench is on the contact between the monzonite and limestone, south of Mystery Creek and near the northeast corner of the Southern Cross claim. The ore consists chiefly of garnet containing many thin films and small masses of malachite and azurite. The thin section shows, in addition to garnet, augite, a little sericitized plagioclase, apatite, epidote, and chloritic material. Twin shafts.--The Twin shafts are near the center of the Southern Cross claim. They are in an oxidized zone on the contact of a finegrained porphyry dike intrusive into limestone. The ore was so much decomposed that no microscopic study or determination of the constituent minerals was possible. It is said to carry about $10 worth of gold per t...