Metallogeny of the geodynamic systems of the pulsating expanding earth
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131 sedimentary and magmatic rocks in late Archean and early Proterozoic (Figure 2) (Crustal..,1974). The process of enrichment potassium in Earth's crust was universal, suddenly and global as a geochemical phenomenon. It has received in the geological literature the name " of potassium explosion ". The petrological consequence “of potassium explosion” was an extremely wide development of granites and formation a granite layer in the Earth's crust. The cause of this appearance it is necessary to search in evolution of composition of the mantle. The potassium is the strongest chemical base and carreing out of it is) connected with the change of an acid-basic mode of interaction in the bowels of the Earth. About it testifies the change of composition of fluids in the geological time. The granulite metamorphism of early Archean proceeded under influence of a waterless, sharply restored fluid, in which composition Н 2 and СН 4 prevailed. For late Archean and Proterozoic formations more typically was metamorphism of amphibolite facies, which mineral balance demand high pressures of Н 2 О and СО 2 , otherwise completely oxidized fluid. Thus, the occurrence of water in structure of a deep fluid and potassium explosion are synchronous and, probably, are mutually caused. That was the cause of wide display of acid granites and genetically connected to them deposits of gold, uranium and others lithophile elements. The most ancient granites have age near 3,7-3,5 Gа, however, it were mainly sodium granites – enderbites, whose volume was rather small. Deposits of gold in connection with enderbites are not fixed, that it is possible to explain by domination of waterless granulite at that time. Reprinted with permission from Publishing House Nedra. Addition a resources of gold is made by M.A. Krutoyarskiy ( 2004 ) 132 Table 3. Auriferous formations and their resources of gold on the Earth Geochronology 3,0- 2,8 Ga 2,7- 2,6 Ga 2,5- 2,4 Ga 2,3- 1,7 Ga 1,6- 1,0 Ga 1,0- 0,54 Ga 540- 360 Ma 360- 250 Ma 250- 70 Ma 070- 20 Ma 020- 001 Ma Type auriferous deposit: I group. Pre-orogenic volcano-sedimentary ore formations: 37,000 t / 41.6 % 1. Аu-Fe-S volcano- sulphide ore deposits: 5,000 t / 5.6 % 1,000 1,400 1,100 900 600 2. Аu-Fe-S carbonic- sedimentary ore deposits: 17,000 t / 19.1 % 1,200 900 1,300 3,400 2,000 2,700 4,600 900 3. Аu-Fe-S volcano- sedimentary ore deposits: 15,000 t / 16.9 % 2,000 8,500 900 2,200 1,000 400 II group. Post-orogenic plutono-volcano ore formations: 52.000 t / 58,4 % 4. Au – Cu porphyry ore deposits 5,000 t / 22.5 % 2,000 2,800 5,000 5,000 5,200 5. Аu-Qu replacement carbonate ore deposits: 5,000 t / 5.6 % 2,530 2,470 6. Аu-S polymetallic vein in granite ntrusions: 14,000 t / 15.7 % 400 3,600 5,000 4,500 500 7. Аu-Ag epithermal- hydrothermal deposits: 9,000 t / 10.1 % 900 1,500 2,900 1,800 1,900 8. Аu-Sb-Hg epithermal- hydrothermal deposits: 2,000 t / 2.3 % 250 750 500 350 250 9. Аu-Cu-U deposits Olympic Dam type: 2,000 t / 2.3% 2,000 10. Old metamorphic Au placers: 80,900 t / 41.5 % 80,00 0 900 11. Mesozoic-Cenozoic detrital Au placers: 23,000 t / 11.8 % 2,000 4,000 7,000 10,000 12. Entombment Au-U weathering crust discordant type : 2,000 t / 1.0 % 2,000 Total Au: 195,000 t 2,000 90,700 1,800 1,300 5,800 3,400 4,650 16,950 26,630 23,320 18,450 Total Au: 100.0 % 1.0 46.5 0.9 0.7 3.0 1.7 2.3 8.7 13.7 12.0 9.5 133 The change of geodynamic regime at development of the Earth in late Archean was most likely caused by the beginning of its expansion. We explain the process of oceanic formation by the general expansion of the Earth and, consequently, on the area of the distribution oceanic crust. Relative distributions of the areas of continental and oceanic crust show, that in order to account for the oceanic formation it is possible to assume the increaseing of the Earth’s surface approximately in 2.5 times (Larin, 1980). The geosynclinal structures began to start on continents in Archean-Proterozoic time. The volcano- sediment formations were deposited on the oceanic type crust in the troughs, as the result of this process the green-stone belts were formed. The formation of the ocean is a relatively young phenomenon. It is reliably dated to start in the late Paleozoic and continued with maximal activity in Mesozoic and Cenozoic aras. Most probably, the Pacific ocean is an exception, because its peripheral structural features do not preclude initial growth in early Precambrian time (Khain, 1971; Pushcharovsky,1972). The Earth’s expansion, as estimated by the rate of the growth of the oceans, evidently, accelerated in current of time. The total area of the “young” oceans ( the Atlantic, Indian, and Arctic), approximately equals to the “old” Pacific ocean. The area of the bottom of all oceans has particularly increased sharply at Mesozoic – Cenozoic eras, that is complied with the increasing volume of water in oceans and indirectly with formation of a rich deposits of gold, uranium and rare lithophile metals in the geosynclines and areas of tectono- magmatic activization. The lamination of external geosphere of the Earth on the crust, pirolite and gipolite with rather contrast distribution of potassium, rubidium and, accordingly, radiogenic strontium postulated in the past time the contrast between the geochemical character of allocation of these elements in the zone of sedimentation, depending on the process of the ocean formation, which subsequently resulted in disclosure of more and more deeper horizons of the planet. The carbonates of calcium fix the isotope composition of strontium in the water, from which they fall out, that allows to consider the evolution of the ratio 87 Sr / 86 Sr in the ocean’s water of the Earth. The curve, describing the evolution of isotope composition of strontium in the oceans at that time appeared rather peculiar (Figyre 3),(Faure and Powell, 1972). Three cardinal perturbations are clearly prominent on it, which, obviously, reflects essential changes of the image of the Earth. The data show exponential increase of the relation 87 Sr/ 86 Sr in waters, circumfluent of the planet during the period from 3,0 up to 1,1 Ga. The extrapolation of this curve until now has resulted to the modern value of the isotopic relation of strontium in the continental crust. However, in late Precambrian, approximately on the boundary of middle and upper Riphean, this relation sharply deviates from the exponential dependence (perturbation А) that testifies to the appearance of a source with the low isotope attitude of strontium exposed on the extensive territory. According to V.N.Larin (1980), it is, most probably, connected with the beginning of active the ocean formation, during which low potassium emanated the tholeiite basalts in huge amounts, that 134 accompanied the formation of the oceanic depressions. It is possible to Reprinted with permission from Publishing House Nedra. Taken from Larin (1980). Modified by Krutoyarskiy ( 2004 ). connect the sharp failure of the curve (perturbation В), coming on the end of Paleozoic and beginning of Mesozoic, with the acceleration of the processes of ocean formation in Mesozoic era, when there was disclosure the Atlantic and Indian young oceanic depressions alongside with proceeding expansion of the existent Pacific ocean. The acceleration of the ocean formation, connected with the expansion of the Earth, by all means should cause the strain, and at the end the break of the mantle layer restite in the middle part of the ocean couch. It accompanied by the rise and output on the surface the again formed silicate mattress of the layer B, arising by the way of metasomatism of the intermetalic layer C of the upper mantle. The content of Rb in intermetalic connections of the layer C should indicate initial concentration of this element on the planet and, hence, should not be less, than in gipolite. In this connection, the sharp increase of the relation 87 Sr / 86 Sr in oceanic carbonate sediments (perturbation С) is explained (Figure 3). At the pressure of level 10 GPа and above, the formed silicate mattress should be represented by spinel-garnet mineral association, whereas at reduction of pressure will prevail ever more pyroxene-olivine paragenesis. As far as the isomorphic capacity of lattices olivine and pyroxene is much lower, than at garnet and spinel (in the attitude of potassium, uranium and others lithophile elements), the change of mineral paragenesis, formed by metasomatic way in the bowels of middle oceanic ridges, (necessarily) should necessarily be accompanied by an increasing the gab of these elements. Exactly here it possible that a huge source which was caused by late Jurassic the perturbation C in geochemistry of 135 potassium and strontium in the zone of sedimentation at the bottom of oceans of the Earth (Larin, 1980). The deep-water red clays of pelagian parts of the oceans along with the high contents of ore elements have a sharply increased concentration of potassium and uranium. In the light of what has been stated above, it should be connected, as far as the ore matter, to axial parts of oceans, with process of silication intermetalic joints of the upper mantle. Admit the community of sources for these elements and ore matter, and also the same cause of conditionality of characteristic "failures" on the curve evolution of potassion and radiogenic strontium in Mesozoic-Cenozoic, it is possible to involve the data of isotopic strontium for defining the time of the beginning of entrance ore matter through the axial zone of oceanic couch. According to the curve, reflecting variation of the relation strontium at ocean’s carbonates during the Phanerozoic, the first portions of ore matter could begin to enter from the end of late Jurassis time (150-140 Ma), but from the beginning of Cenozoic the process of endure of ore matter has become more intensive. At that same time on the continents and transitive zones to the oceans took place the processes of tectono-magmatic activity which generated a lot of gold deposits (Table 2, Figure 4). The formation of large and superlarge deposits of gold with reserves more than 500-1000 t is connected with the periods of tectono-magmatic activity, at the processes of reuvination and secondary concentration of gold by fluid and hydrothermal solutions, rising from more young intrusions of granites and other magmatic masses, lieing on significant depths from 1-5 up to 10 km (Boyle, 1955; Bache, 1987; Rundquist, 1993; Konstantin et.al, 2000; Safonov, 2003; Potters et al., 2004). REFERENCES Bache J.-J. (1987). - World gold deposits, a geological classification. - Elsevier Science Publishing Co., NY, p. 178. Boyle R.W. (1955). - The geochemistry and origin of the gold bearing quartz veins and lenses of the Yellowknife Greenstone belt. - Econ. Geol., N 50, pp.51-66. Betekhtin A.G. (1950). - Mineralogy. – State Publishing House, M., p.956. Emmons W.H. (1937). - Gold Deposits of the World. - NY. Engel A.E.J., Itson S.P. et. al. (1974). - Crustal evolution and global tectonics: a petrogenic view. - Geol. Soc. of America Bull., v.85, N 6, pp. 843- 858. 136 Gold. (2000). - Mineral Summary. - NDMP, Brazil, v.20, p.54. Gold. (2004) - Minerals Yearbook, Metals and Minerals. USGS. Washington,.pp. 32.1-32.13. Goldsmidt V.M. (1937). – Crystalochemistry. –Khimtheorizdat, M . Goncharov V.I., Vashilov Yu.Ya., Sidorov A.A.,, Volkov A.V., Gorjachev N.A. (2004) - The Deep structure of large precious metal deposits of northeast Asia. - ИГЕМ the Russian Academy of Science, M., pp.69-94. Hutchinson R.W. (1975). - Lode gold deposits; the case for volcanogenic derivation. - Portland, Oregon, Dep. Geol. Miner. Ind. Bull., , pp.64-105. Konstantinov M.M., Nekrasov E.M., Sidorov A.A. et.al. (200). The auriferous giants deposits of Russia and World. - Scientific world. M, p. 270. Krutoyarskiy M.A., Larin V.N.Larin, Magakian I.G., Smyslov A.A. (2000) – The Brief Explanatory Note to “ Metallogenic Map of the Geodynamic Systems of the Pulsatory – Expanding Earth,” scale 1:15,000,000. - IANSS, S- Pt.,Chicago, p.76. Larin V.V. (1980). – The hypothes of primary hydridic the Earth. – Nedra, M., p.215. Petrovskaya N.V. (1955). - . To the question on principles of mineralogical classification of types initial auric ores. – Trudy NIGRI, gold, vyp..20. Peterman Z.E., Hedge C.E., Tourtelot H.A. (1970). - Isotopic Composition of strontium in sea water throughout Phanerozoic Age. -_Geochim. et Cosmochim. Acta, v.34, pp.105-120. Pushcharovskiy Yu.M. (1972). - Introduction at tectonic of the Pacific segment of the Earth. - Nauka, М.,, p. 222. Ridler R.H. (1976). - Relationship of mineralization to volcanic stratigraphy in the Kirkland lake - Larder lake area, Ontario.-Geol. Assoc. Can. Proc., N 21, pp.33-42. Rudnik V.A., Sobotovich E.V. (1984). - The Early history of the Earth. - М., Nedra, p.349. Rundquist D.V. (1993). – The epochs of reuvenation Precambrian crust and their metallogenic meaning. - Geology of ore deposits. N 6, pp. 467-480. Safonov Yu.G. (2003). – The auriferous deposits of the World - genesis and metallogenic potential. - Geology of ore deposits, т.45, N 4, pp. 305-320. For G., Pauell J. (1974) - Isotopes of strontium in geology. – Izdan. Mir, M. p.214. orks the forecast was confirmed and the last “Gold Klondike” of the XX century in Arctic was detected. In 1996 Krutoyarskiy has written the Shumilin M.V. (1996) - Balance of world production and resources of Uranium. – Rasvedka i okhrana nedra., N3, pp.10-11. 137 About the Editor and Author Mikhail A. Krutoyarskiy graduated from the Leningrad State University (USSR) in 1953 as an exploration geologist. Since 1954 to 1971 his industrial and scientific activity was connected with Leningrad Scientific Research Institute of Arctic geology. Krutoyarskiy has worked in geological mapping and searching of diamondiferous kimberlites and placers on the Siberian Platform. In 1956 he participated on discovery of a new Olenek region and exploration the first in Russia diamondiferous kimberlite pipe “Leningrad”. Between 1959 & 1968, he has worked as a research geologist for exploration of the Yakut province, studying kimberlite rocks; mineralogy and physical properties of natural diamonds. In 1961 Krutoyarskiy has created the “Forecast map of searching a new diamondiferous deposits on the North Siberian platform” (scale 1:500,000). From 1969 to 1971 he mapped an ancient complex of metamorphic terrain on Anabar shield. As a result of these explorations he had written a lot of scientific reports, articles and two books. In 1968 he successfully defended his Ph.D. thesis on the diamondiferous of the Western Yakut kimberlite province. Since 1972 until 1992 Krutoyarskiy worked for the Scientific Research Institute Okeangeologia as a senior scientific geologist, where he has led a new scientific direction - the estimation of prospects the Arctic shelf for the diamonds and gold placers. To resolve this problem he had made in 1972 the “Forecast map of auriferous North-Taimyr province” (scale 1:1,000,000), where he segregated 9 perspective areas for searching gold deposits and placers. Among them has been Cheliuskin peninsula, on which the Polar expedition has found two gold placers in 1981. As a result of these was doctoral thesis of the “Metallogeny of Geodynamic Systems of the Pulsating-Expanding Earth”, to which he has compiled the “Metallogenic Map of the Earth”. The doctoral thesis and the map have been completed already after his emigration in USA at the end of 1996. Now he is working as a consultant geologist in U.S. Geological Survey and at the International Academy of Natural and Social Sciences. The vast scientific interests of Krutoyarskiy have found reflection in the numerous published works, devoted to various questions of the geology, petrology and mineralogy of kimberlites, diamonds and gold; to the forecast metallogenic diamondiferous and auriferous maps. He has authored or coauthored of 5 books and more than 100 professional reports, articles, geological and metallogical maps. The completion of the collective work " Metallogenic Map of the Geodynamic Systems of the Pulsating-Expanding Earth”(scale 1:15.000.000) and the “Explanatory Note” to it has allowed M.Krutoyarskiy (as responsible editor) to take part in the International Geological Congresses in Brazil (2000), Italy (2004) and Norway (2008). Presentation of this Metallogenic map and Explanatory note has caused the great interest a geologists of the world. The Russian Academician N.A.Shilo had written in his review, that this work “will be splendour of modern geology” and allows on a scientific basis to discover the deposits of useful minerals, where “Sezam opened the vaults to his treasures”. 138 (Click on the Map to open the full Map version) (Click on the Map to open the full Map version) 139 140 141 142 Yüklə 0,51 Mb. Dostları ilə paylaş:
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