The Elements of economic geology

Bibliographic data

Monograph

Identifikator:: 1773832379

URN:: urn:nbn:de:zbw-retromon-172798

Document type:: Monograph

Author:: Gregory, John W. http://d-nb.info/gnd/11683014X

Title:: The Elements of economic geology

Place of publication:: London

Publisher:: Methuen

Year of publication:: 1928

Scope:: XIV, 312 S.; graph. Darst.

Digitisation:: 2021

Collection:: Economics Books

Usage license:: Get license information via the feedback formular.

Chapter

Document type:: Monograph

Structure type:: Chapter

Title:: Part II. Ore deposits

Collection:: Economics Books

ORES OF LEAD, ZINC, AND SILVER 10; been worked to a depth of 1800 feet. It was capped by an Iron gossan which stood as a ridge above the plains, and was "pegged ” out as a tin lode, A shaft was sunk and instead of tin found rich deposits of silver. The arid nature of the Country had led to secondary enrichments so large that their yield caused a serious fall in the price of silver. The UPper part of the lode was famous for its beautiful minerals, and its many new species of iodides, bromides, and chlorides, which survived owing to the arid climate. The treatment of the ore was troublesome, and led to the invention of the flotation process to separate the rhodonite and blende, Which are of the same specific gravity. The lode is in pre-Pal®ozoic gneiss and schists, which contain sillimanite and abundant garnets that are earlier than the ores, A bulge on the side of the lode and some Secondary arches of quartz led to its description as a saddle-lode (E. F. Pittman, 1892; J. B. Jacquet, Mem. GCSNSW. No. 5, 1804, and Beck, Rec. G.S.N.S.W., vii, 1900, p. 27). The footwall has vast slicken-sided surfaces, and the author in 1904 (Melbourne Argus, and Science Pro- 87€sS, 1906, p. 131) explained the formation as a fault lode enlarged by metasomatic action at the shallow depth in- dicated by the abundant fluorite. The lode is a steeply inclined sheet which tapers downwards. This view has been demonstrated in the monograph on the field by C. W. Andrews (Mem, GSNSW., Geol., No. 8, 1922), who has shown that the silicates in the lode were formed in connection with the faulting, SECTION B. SecoNDARY ORES (¢) Disseminatep Orgs or Mississippi—The Mississippi valley (Fig. 34) contains important lead and zine ores in Paleozoic limestones free from igneous rocks. The ores have been the subject of long controversy as to whether they were formed by ascending or descending solutions. The field of Joplin “in S.W. Missouri is in Carboniferous limestone. The fields ip S.E. Missouri consist of pre-Pal®ozoic rocks Covered by Tepresentatives of all the systems from the Cambrian to Upper Carboniferous. Its lead and zinc ores Are mainly in Cambrian rocks, which include in ascending order, the Lamotte Sandstone, the Bonneterre Dolomite,

Access restriction

Copyright

fullscreen: The Elements of economic geology

Monograph

Chapter

Table of contents

Download

Monograph

Chapter

This page

Image fragment

Citation links

Citation recommendation