GEOLOGICAL SURVEY CIRCULAR 705 Mineral Resources of Antarctica Mineral Resources of Antarctica Compiled ancl eclitecl &y N. A. Wright ancl P. L. Williams GEOLOGICAL SURVEY CIRCULAR 705 1974 United States Department of the Interior ROGERS C. B. MORTON, Secretary Geological Survey V. E. McKelvey, Director Free on application to the U.S. Geological Survey, National Center, Reston, Va. 22092 CONTENTS Page )Lbstract ---------------------------------------------------------------- 1 Introduction ------------------------------------------------------------ 1 ldineral occurrences ------------------------------------------------------ 3 Sand and gravel ---------------------------------------------------- 3 Other nonmetals ---------------------------------------------------- 3 Iron ---------------------------------------------------------------- 10 Copper --------_____ -.- ____ - __ - _________ - ___ - ___ - --__ ----------------- 11 Gold and silver ------------------------------------------------------ 11 ldolybdenum ___________________________________ ---_ -~- --------------- 11 Other metals -------------------------------------------------------- 11 Potential resources _--- _-_________ - ________ - ____ ---_----__ ---------------- 11 ldanganese nodules _____________________________ ---____ --------------- 11 Geothermal energy --------------------------------------------------- 12 VVater (as ice) ------------------------------------------------------ 15 Coal ---------------------------------------------------------------- 15 Oil and natural gas -------------------------------------------------- 15 Economic potential of the Dufek intrusion, Pensacola Mountains --------- 17 Mineral resource estimation ---------------------------------------------- 18 Geologic provinces of Antarctica and presumed relationships to geologic provinces of neighboring Gondwana continents ----------------------- 18 Statistical speculation ------------------------------------------------ 24 ~erences cited --------------------------------------------------------- 28 ILLUSTRATIONS Page FIGURE 1. Classification of mineral resources ----------------------------­ 2 2. Map showing known occurrences of potentially valuable minerals in Antarctica ----------------------------------------------- 4 3. Computer plot of manganese nodule occurrences in the oceans south of lat 60° S. ____________________________ :.. __________________ _ 13 4. Schematic representation of major features of the geology and ore deposits of Gondwanaland ----------------------------------- 20 5. Expected mineral deposits, Antarctica --------------------------- 26 TABLES Page TABLE 1. Mineral occurrences in Antarctica ----------------------------­ 8 2. Marine manganese nodule occurrences south of lat 60° S. -------­ 12 3. Expected number of mineral deposits in exposed areas of Antarctica and the expected number of deposits to be discovered ----------- 25 III Mineral Resources of Antarctica Compiled and edited by N. A. WRIGHT and P. L. WILLIAMS ABSTRACT however, is whether they can be found. The Although the existence of mineral deposits in Ant­ problem~s of finding deposits include such arctica is highly probable, the chances of finding them things as lack of rock outcrops, an extremely are quite small. Minerals have been found there in thick ice cover, almost permanently frozen great variety but only as occurrences. Manganese nodules, water (as ice), geothermal energy, coal, petro­ coastal waters, and no population. The social leum, and natural gas are potential resources that and economic costs of search are high, but could perhap·s be exploited in the future. On the basis these costs have not stopped similar ventures of known mineral occurrences in Antarctica and rela­ in the past once zeal was stimulated, even when tionships between geologic provinces of Antarctica and the chances of success were small. The danger those of neighboring Gondwana continents, the best dis­ lies in an unwarranted stimulation of zeal be­ covery probability for a base-metal deposit in any part of Antarctica is in the Andean orogen; it is estimated cause of either a misinterpreibation of terms or to be 0.075 (75 chances in 1,000). a failure to separate the appraisal of the re­ source from the actual costs involved in ex­ INTRODUCTION ploration and development. This circular atte·mpts to ( 1) pre~sent a sur­ The resource estimates are based on (1) vey of the known mineral resources of Ant­ present knowledge of mineral occurrences in arctica and (2) estimate Antarctica's mineral­ Antarctica ; ( 2) a theoretical geologic recon­ resource potential on the basis of known struction of the ancient supercontinent of mineral occurrences in Antarctica and known Gondwanaland and of the relationship of the mineral deposits of neighboring continents. It major geologic provinces of Antarctica to com­ does not attempt to make any judgements on parable ones in the adjacent continental masses whether or not the mineral resources of Ant­ of South America, Afric·a, India, and Aus­ arctica should be explor.ed for and exploited. tralia; and (3) the extrapolation of known Rather, an objective analysis is given of the resources in these adjacent, formerly contigu­ present geologic information, aimed. at apprais­ ous landmasses to determine the expected fre­ ing the mineral resources of Antarctica. quency of comparable occurrences in Antarc­ About 98 percent of the surface of Antarc­ tica. This circuitous reasoning process produces tica is cove~red by ice. The lack of exposed rock estimates of anticipated resourc-es that are means that the survey of mineral re1sources of subject to continuous review, modification, and Antarctica presented here is incomplete. An refinement. It offers the most reasonable assess­ analysis resulting from such an incomplete ment of the mineral resources of the continent survey can be potentially misleading if taken in view of the extremely limited amount of out of context. Geologic studies to date, limited exposed bedrock and the extremely limited de­ almost exclusively to exposed rock masses that tailed studies of these exposures. have been analyzed primarily for scientific pur­ The terminology used in this summary is poses, have not revealed any mineral concen­ based upon the definitions presented by V. E. trations rich enough to be classified as com­ McKelvey in 1973. Figure 1 is a classification mercially exploitable ore deposits, but the of resources adopted jointly in 1974 by the U.S. probability that mineral deposits exist in Ant­ Geological Survey and the U.S. Bureau of arctica seems to be high. The crucial factor, Mines (Pratt and Brobst, 1974, fig. 1). Within 1 TOTAL RESOURCES IDENTIFIED UN DISCOVERED Demonstrated SPECULATIVE HYPOTHETICAL Inferred (In undiscovered (In known districts) districts) Measured I Indicated 2 ~ 0 z R E s E R v E s t 0 (.) LLI l I - I I + iii c: -~ Ill E R E s 0 u R c E s ~ 2 Ill ~ a.. 0 z 0 - r- - (.) LLI + + + + al iii :::l c: (/) "O"D ro E .0 :I (/) I I I I 1 -<~-------- Increasing degree of geologic assurance ------------1 FIGURE 1.-Classification of mineral resources. Modified from Pratt and Brobst (1974, fig. 1). the f~amework of figure 1, Antarcticja now has phatically supported by the present high-cost no known economically recoverable re~sources practice of importing other energy sources to of any category, nor does Antarctica have any support scientific stations in Antarctica. An­ known mine~al districts. The few localities other example of mineral occurrence is the where valuable minerals have been identified appHarance of gas in a single drill hole, which must be classified as mineral occurrences; that was immediately capped. Favorable host rocks, is, occurrences of minerals that could constitute favorable structures, and a fir:st "smell" of gas a resource if present in sufficient quantity but do not constitute an identified resource; rather that have not been studied adequately to deter­ the gas is a proved mineral occurrence that mine quantity. These occurrences would rate supports estimates of the speculative resource even lower than submarginal in figure 1 in de­ potential for gas and oil. All mineral occur­ gree of economic feasibility. Water and coal rences in Antarctica should be considered in could constitute identified resources in Antarc­ this same context. tica. Ice brought to the Antarctic coast by a The resources of Antarctica are almost ex­ glacier contains a volume of water that can be clusively in the category of speculative re­ estim~ated. The coal resources in the Beacon sources on the basis of figure 1. Their position rocks have been sufficiently measured in places in this category is supported by the few min­ to p~ermit estim~ation of volumes. Present mar­ eral occurrences that have been found. Ranking ket conditions, as well as quality and location of such resources according to feasibility of of the coal, indicate that it is not now possible economic recovery is a futile exercise. Such for the coal resources to be considered econom­ ranking would depend on what, if anything, is ically usable ; the identified coal and water are found, where it is found, and the economic definitely submarginal. This oonclusion is em- market at the time of finding. 2 Large accumulations of minerals very prob­ and tenor of deposits are nearly absent in the ably occur in Antarctka, for no other continent literature; t~able 1 summarizes what is known is void of miner,al deposits. The major question about most of the sand and gravel occurrences. is whether these