UNITED STATES MINERAL RESOURCES 



ZING 



By Helmuth Wedow, Jr., Thor H. Kiilsgaard, Allen V. Heyl, and Robert B. Hall 



CONTENTS 



Abstract of conclusions 



Introduction 



Exploitation 



Geologic environment 



Geochemistry 



Ore minerals 



Types of deposits 



Contact-metamorphic deposits 



Irregular replacement deposits and asso- 

 ciated fissure fillings 



Vein deposits 



Stratabound deposits in metamorphic 



rocks 



Stratabound deposits in carbonate 

 rocks (Mississippi Valley- and 



Alpine-type deposits) 



Stratiform deposits 



Deposits formed by'supergene enrich- 

 ment or laterization 



Resources 



Prospecting techniques 



Problems for research 



Selected references 



Page 



697 

 698 

 699 

 700 

 700 

 701 

 702 

 702 



703 

 703 



703 



704 

 704 



705 

 706 

 708 

 709 

 709 



FIGURE 



77. 



Graph showing the production of primary zinc 

 in the world and in the United States 1830- 

 1970, and consumption of zinc, including 

 scrap, in the United States 1938-1970 



TABLES 



149. 

 150. 



153. 



Consumption of zinc in the United States, 1969_ 

 Slab zinc consumption in the United States, by 



industry uses 



Distribution of zinc oxide and leaded zinc oxide 



shipments, by industries 



Composition, zinc content, and selected physical 



characteristics of the common ore minerals 



of zinc 



Identified and undiscovered zinc resources of 



the United States and the world 



699 



698 

 698 

 698 



702 

 706 



154. 



155. 



Recoverable identified zinc resources of the 

 United States grouped by major geologic re- 

 gions 



Recoverable identified zinc resources of the 

 world 



Selected examples of types of zinc occurrences 

 that contribute to the total of conditional and 

 undiscovered zinc resources of the world 



707 



707 



707 



ABSTRACT OF CONCLUSIONS 



Zinc, a ubiquitous minor element in the earth's crust, has 

 been used industrially for many centuries, at first only as an 

 alloy component, later as the metal and as a component of 

 chemical compounds. Today it stands, in tonnage produced, 

 as the fourth most important metal in world trade. About 

 150 million metric tons has been used since the beginning of 

 the 19th century, and projected growth rates suggest that 

 this amount will more than double by the end of the 20th 

 century. Current annual world production exceeds 5 million 

 metric tons. Of this tonnage the United States produces 

 about 9 percent, but it consumes more than three times the 

 amount it produces. World resource estimates indicate that 

 recoverable identified resources (that is, reserves) are about 

 235 million metric tons, of which 45 million is in the United 

 States. Total world identified and undiscovered zinc resources 

 are estimated at over 5 billion metric tons, about one-tenth 

 of which is in ores of grade sufficient to be exploitable under 

 existing economic conditions. Zinc is produced from mines 

 in more than 40 countries on all continents except Antarctica : 

 six leading countries — Canada, Russia, United States, Peru, 

 Mexico, and Australia — produce more than 60 percent of the 

 world's total. 



The resource potential of zinc suggests that several hun- 

 dred million tons of contained metal are in conventional de- 

 posits that await discovery by conventional search techniques 

 and improvement of recovery methods; these conventional 

 resources are dominated by the massive sulfide ores in meta- 

 morphic rocks, in which zinc occurs chiefly with copper and 

 lead, and by the stratabound deposits in carbonate rocks, in 

 which lead is an essential coproduct and cadmium a signi- 

 ficant byproduct. Potential resources in both conventional 

 and unusual deposits are estimated in the billions of tons; 

 these include both low-grade and higher grade deposits for 

 which new recovery methods must be developed before they 

 can be exploited, such as the Kupferschiefer in Europe, the 

 base metal-rich muds deposited from hot brines in Red Sea 

 deeps, and the lead- and zinc-bearing manganese nodules on 

 the Pacific sea floor. The concept that zinc can be concen- 

 trated in the geochemical environments of tropical and per- 



U.S. GEOL. SURVEY PROF. PAPER 820 



