UNITED STATES MINERAL RESOURCES 



LEAD 



By H. T. Morris, Allen V. Heyl, and Robert B. Hall 



CONTENTS 



Abstract of conclusions _-_ 



Introduction 



Ancient uses 



Modern uses 



Outlook 



Exploitation 



Geologic environment 



Geochemistry 



Ore mineralogy 



Types of deposits 



Strata-bound deposits of syngenetic origin. 

 Strata-bound deposits of epigenetic origin- 



Volcano-sedimentary deposits 



Replacement deposits 



Veins 



Contact pyrometasomatic deposits 



Resources 



Reserves 



Conditional resources 



Hypothetical resources 



Speculative resources 



Prospecting techniques 



Problems for research 



References cited 



FIGURE 



39. Production of primary lead in the world and in 

 the United States, 1830-1971, and consump- 

 tion of lead, including scrap, in the United 

 States, 1918-71 



TABLES 



63. World mine production of lead in 1969, by coun- 



tries 



64. Lead consumption in the United States, by prod- 



ucts, in 1969 ^ 



65. Estimate of world reserves of lead, by regions or 



countries 



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ABSTRACT OF CONCLUSIONS 



Lead has been used by man for approximately 6,000 years; 

 it is now the fifth most important metal of trade in our in- 

 dustrialized economy. Lead occurs in a wide variety of ore 

 deposits that are mined in more than 40 countries on all 

 the continents except Antarctica. The world reserves are 

 here estimated to exceed 140 million short tons of lead con- 

 tained in ores, equivalent to a 31-year supply at the 1971 

 world rate of consumption. The reserves of the United States 

 are estimated to constitute 38,185,000 short tons of lead; 

 average annual domestic consumption during the period 

 1961-70 was 1,240,000 short tons, of which about 43 percent 

 was recycled scrap. The outlook for the continuing discovery 

 of additional reserves and resources at a rate that exceeds 

 consumption is believed to be excellent; many of these un- 

 discovered ore deposits are assumed to be comparable in 

 tonnage and grade with known ore bodies. 



Conditional resources of conventional types but low grades 

 are contained in strata-bound, massive sulfide, and. other 

 kinds of deposits in several areas of the United States. 

 Conditional resources of unconventional types ar« contained 

 in lead-bearing manganese nodules on the sea floors, in the 

 Kupferschiefer and related strata of Europe, in the Belt 

 Supergroup of the Northwest United States, and in sediment 

 in thermal deeps of the Red Sea and other oceanic areas. 

 These conditional resources may total as much as 1.5 bil- 

 lion tons of lead, most of which is in the manganese 

 nodules. Hypothetical and speculative resources together may 

 equal half again as much as the known world reserves. 



INTRODUCTION 



ANCIENT USES 



The earliest uses of lead greatly antedate the 

 earliest uses of iron, and lead, with copper and 

 silver, may have been one of the first metals smelted 

 from sulfide or oxidized ores. Because of its rela- 

 tively common occurrence, the simplicity of its 

 metallurgical reduction, its high density and low 

 fusibility, and its softness and malleability, lead was 

 used by many ancient peoples. As early as 3800 B.C. 

 it was used by an artisan or priest to fashion a 

 figurine that was discovered at the site of the Tem- 

 ple of Osiris at Abydos, in upper Egypt (Mitman, 

 1922, p. 596). During the succeeding centuries, it 



U.S. GEOL. SURVEY PROF. PAPER 820 



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