An Overview of Sandstone Lead Deposits and their Relation to Red-Bed Copper and Carbonate-Hosted Lead-Zinc Deposits
A. Bjørlykke, D. F. Sangster, 1981. "An Overview of Sandstone Lead Deposits and their Relation to Red-Bed Copper and Carbonate-Hosted Lead-Zinc Deposits", Seventy-Fifth Anniversary Volume, Brian J. Skinner
Download citation file:
Deposits of galena occurring as disseminations in basal quartzitic sandstones constitute a distinct and characteristic deposit type. By world standards they are relatively minor yet they constitute an important resource in some countries.
Host rocks to the deposits are basal quartzitic sandstones deposited in low latitude positions on a sialic basement. In several areas, the basement is anomalously rich in lead relative to average granite. Depositional environments range from continental to shallow marine.
The deposits are characteristically low grade, lead dominant, pyrite free, and silver poor. A common feature is a high-grade core surrounded by a lower grade halo. If present, zinc occurs in a position stratigraphically higher than the lead.
Galena cements sand grains, with the higher grades occurring in originally more porous zones. Silica, commonly chalcedonic in the younger deposits, is the next most common cement.
The preferred genetic model involves transport of metals laterally from adjacent basement highs through permeable channels in sandstones to an environment with a sufficiently high H2S content to precipitate galena and minor amounts of other sulfides.
From a comparison of several features of these deposits with those of two other major intracratonic, sediment-hosted, base metal deposit types (red-bed copper and carbonate-hosted lead-zinc), it is concluded that these three deposit types are not only clearly separate entities in terms of their tectonic and sedimentary environments but were probably formed at different stages of continental evolution.
Figures & Tables
Seventy-Fifth Anniversary Volume
The first notions of a new journal came to J. E. Spurr during the closing days of 1904. When he shared his thoughts with friends in Washington, D. C., they were so enthusiastic about the suggestion that they formed themselves into an ad-hoc committee to seek ways to implement the idea. The ad-hoc group met informally for several months and by May of the following year was ready to announce the birth of an unusual new publishing company and the journal the company would produce. The first formal meeting of the Economic Geology Publishing Company took place on May 16, 1905. The first issue of the new journal appeared in October of the same year, and the first volume was completed in December 1906. The birthing was not easy, but it was successful because the founders provided much of the financing as well as the first papers. The story of those earliest days and the many struggles of the fledgling journal is engagingly recounted by Alan M. Bateman in an article published in the Fiftieth Anniversary volume.
From inception, management of the journal has differed from the management of most scientific journals. There was no sponsoring society, so the founders raised capital by incorporating and selling shares in the venture. The journal has been owned and published by the Economic Geology Publishing Company ever since. There is no record that the founders experienced difficulties in selling shares in the Company, but they must have had some because the Publishing Company had a goal that other corporations(and presumably many of the investors) would have found difficulty in understanding: the new corporation was committed to keeping the books balanced but not to making a profit.
Initially incorporated in the District of Columbia, the Publishing Company was reincorporated in 1970 as a nonprofit membership corporation in Delaware. The modification in corporate status came in response to a suggestion made by the Internal Revenue Service.
The affairs of the Publishing Company are controlled by a Board of Directors, and the journal is sold to the public by direct subscription. Day-to-day operations of paper selection, review, and printing are in the hands of the Editor, while business matters, such as subscriptions and advertising, are in the hands of the Business Editor.
The one tie the Publishing Company has with a society was instituted many years after the journal. was founded—with the Society of Economic Geologists. When the Society was founded in 1920 it first considered publishing its own bulletin. Because the venture seemed financially questionable, and the coffers of the new society were bare, an arrangement was reached whereby members of the Society first received offPrints of papers written by its members and eventually Economic Geology as