20_2

Volume 21, 5, 2002

I.A. Alexandrov, O.V. Avchenko. Comparative thermobarometry of metamorphic complexes, and the geodynamic model of the relationships between the Aldan and the Dzhugdzhur-Stanovoy block (Aldan-Stanovoy shield) 3

V.A. Trunilina, S.A. Babushkina, Yu.S. Orlov.Composition and the genetic aspects of formation of the latite-series granitoids of the Polousnyi Range (Northern batholithic belt of the Verkhoyansk-Kolyma mesozoids) 15

Yu.D. Zakharov, O.P. Smyshlyaeva, A.M. Popov, V.V. Golozubov, A.V. Ignatiev, T.A. Velivetskaya, K. Tanabe, Y. Shigeta, H. Maeda, T.B. Afanasyeva, A.A. Kolyada, A.K. Cherbaji, K. Moriya.Oxygen and carbon isotope composition of the Cretaceous organogenic carbonates, the Koryak Upland. Paper 2. Talovka River basin (Koryak Upland) 28

V.P Tarabukin.Ordovician conodont biostratigraphy in the Sette-Daban Range, northeast Asia 41

S.Ye. Aprelkov, P.S. Bogdan, S.V. Popruzhenko. Paleovolcanic structures in the Unneivayam volcanic field, Koryak Upland, and related mineralization from geological and geophysical data 51

N.G. Shkabarnya, G.N. Shkabarnya. Peculiarities of the structure of sedimentary basins in the Primorye Territory (from the data of electric prospecting) 62

D.V. Kovalenko, Ye.Ye. Chernov.Remagnetization of Cretaceous and Paleogene units of Kamchatka and southern Koryakia 68

K.B. Bulnaev. The source of fluorine from epithermal fluorite deposits, and the character of its evolution 85

L. G. Filimonova, A. V. Chugaev The role of basite matter and host rhyolites in the formation of the pre-ore postmagmatic minerals of the Dukat ore field, Northeast Russia 95

Anniversaries
A.A. Sidorov (70th birth anniversary) 108
V.G. Sakhno (70th birth anniversary) 110
L.P. Eirish (70th birth anniversary) 111

Obituary
L.M. Parfenov (1937-2002) 112

I.A. Alexandrov, O.V. Avchenko
Comparative thermobarometry of metamorphic complexes, and the geodynamic model of the relationships between the Aldan and the Dzhugdzhur-Stanovoy block (Aldan-Stanovoy shield)

The technique of pressure and temperature estimations of mineral assemblages on the basis of the TERMOCALC program is described. PT-conditions of formation of the Sutam complex (Aldan block) granulites and metamorphic rocks of the Zeiskiy and Stanovoy complexes (amphibolite facies, Dzhugdzhur-Stanovoy block) were determined. It is established that the depth of formation of the metamorphic rocks of the Dzhugdzhur-Stanovoy block (amphibolite facies) does not concede, and sometimes exceeds the depth level of granulites of the southern part of the Aldan block. On this basis supplemented with modern isotope data, a new geodynamic model of the relationships between the Aldan and the Dzhugdzhur-Stanovoy block (Aldan-Stanovoy shield) is offered. According to this model, metamorphic events of the Dzhugdzhur-Stanovoy block are closely connected with Proterozoic recrystallization of the Aldan block and occurred under the conditions of subduction of the Stanovoy plate under the Aldan block.

V.A. Trunilina, S.A. Babushkina, Yu.S. Orlov
Composition and the genetic aspects of formation of the latite-series granitoids of the Polousnyi Range (Northern batholithic belt of the Verkhoyansk-Kolyma mesozoids)

This paper presents the results of detailed study of granitoids from the western part of the Northern “batholithic” belt of the Verkhoyansk-Kolyma mesozoids (Polousnyi Range). The granitoid massifs are localized in a regional fault zone. They are preceded and followed by subaerial volcanic eruptions. It is shown that generally the granitoids are close to magmatic rocks of the continental latite series by their mineral, petrochemical and geochemical composition. A combination of non-equilibrium mineral associations in them: basite magmas of increased alkalinity on the one hand, and granitoid magmas, on the other, elevation of crystallization temperatures toward the deep horizons of eroded plutons, a through geochemical character of rocks with respect to both chalcophile and lithophyle, and siderophile elements, and an increase in this geochemical composition in the course of evolution of regional magmatism are attributed to the long existence during the whole Early Cretaceous stage of deep-seated and crustal magmatic chambers. The typomorphic composition of rock-forming, accessory and xenogenic minerals of granitoids and their geochemical parameters permit an assumption of parental magmas incipience at the level of crustal amphibolites under the influence of heat and fluids of abyssal magmas of increased alkalinity. They also allow a supposition of partial shift of the originating granitoid magmas or their saturation in the fluids.

Yu.D. Zakharov, O.P. Smyshlyaeva, A.M. Popov, V.V. Golozubov, A.V. Ignatiev, T.A. Velivetskaya, K. Tanabe, Y. Shigeta, H. Maeda, T.B. Afanasyeva, A.A. Kolyada, A.K. Cherbaji, K. Moriya
Oxygen and carbon isotope composition of the Cretaceous organogenic carbonates, the Koryak Upland. Paper 2. Talovka River basin (Koryak Upland)

Isotopic paleotemperatures obtained for the Albian from the calcitic shells of the brachiopods Penzhinothyris plana Smirnova from the Kedrovka Formation range from 12.5 to 22.7oC. The lower temperature level corresponds, apparently, to the winter seasons; the upper level, to the summer temperatures. Presumably winter isotopic paleotemperatures for the Coniacian, fluctuating from 10.9 to about 14.1oC, were calculated both from calcite of the bivalves Acila (Truncacila) sp. and Nannonavis sachalinensis (Yok.) from the upper Penzhinskaya Formation. Presumably spring-and autumn isotopic paleotemperatures for the Coniacian, fluctuating from 14.1 to 17.7oC, were obtained both for the calcitic rhynchonellid brachiopods, the bivalves Acila (Truncacila) sp., Nannonavis sachalinensis (Yok.), and the scaphopods Dentalium sp. and also for the aragonitic shells of the ammonoids Anagaudryceras sp., Gaudryceras sp., Tetragonites popetenis Yabe, Mesopuzosia sp., Kossmaticeras japonicum Mat., and Scalarites sp.. Presumably, summer isotopic paleotemperatures varied between 17.7o to 22.4oC; they were calculated using data from calcite of the bivalve Nannonavis and the scaphopod Dentalium, and aragonite of the shells of the ammonoids Anagaudryceras, Gaudryceras, Tetragonites, Mesopuzosia, Kossmaticeras, Yokoyamaoceras, Baculites, and Yezoites. The review of new evidence on Cretaceous isotopy and the data in the literature allow us to assume short-term existence of polar ice in the Cretaceous (Early Maastrichtian) only in the southern hemisphere and on the Antarctic continent; however, evidence for the northern hemisphere seems to be compatible with only short-time subfreezing conditions in the Early Cretaceous. Late Coniacian – Early Santonian and Early Maastrichtian time.

V.P Tarabukin
Ordovician conodont biostratigraphy of the Sette-Daban Range, northeast Asia

This paper presents characteristics of Ordovician conodont zones in the Sette-Daban Range. Grounds are given to the range and boundaries of these biostratigraphical units, their assignment to the main regional subdivisions (horizons) in the regional stratigraphic scale. Geographical distribution of zones in the region and significant levels for correlation and paleoecology are also reported.

S.Ye. Aprelkov, P.S. Bogdan, S.V. Popruzhenko
Paleovolcanic structures in the Unneivayam volcanic field, Koryak Upland, and related mineralization from geological and geophysical data

Basing on the analysis of the data of detailed geophysical investigations in the Unneivayam Paleogene volcanic field, Koryak Upland, linear systems (zones) of volcanic domal and caldera structures are distinguished and characterized. Their relationship with ore fields and structures is analyzed, and new ore targets are predicted.

N.G. Shkabarnya, G.N. Shkabarnya
Peculiarities of the structure of sedimentary basins in the Primorye Territory (from the data of electric prospecting)

This paper briefly discusses information about the geological and geophysical characteristics of sedimentary basins in the Primorye Territory. Based on data received from electric and seismic surveys and electric logging, the total longitudinal conductivities of the sedimentary cover were determined. An isoline scheme of the total longitudinal conductivity has been constructed, which made it possible to estimate the occurrence of the different-age basement within the main sedimentary basins.

D.V. Kovalenko, Ye.Ye. Chernov
Remagnetization of Cretaceous and Paleogene units of Kamchatka and southern Koryakia

Petromagnetic investigation of remagnitized and analogous non-remagnetized rocks of Kamchatka and southern Koryakia has been carried out. It showed that remagnitized and non-remagnetized units are in fact similar with respect to their petromagnetic characteristics. Virtually all studied remagnitized units, except some units of the Malkinskiy bulge, did not display any features of chemical and thermoremanent remagnetization. An assumption of thermoviscous remagnetization of units explains the absence of traces of formation of the great concentration of new magmatic minerals, strong thermal treatment of rocks and single-component post-fold magnetization of units with different magnetic minerals (magnetite and hematite). However, this interpretation hardly gives explanation of the long existence of a heat source necessary for warming up rocks to 200-300°C.

K.B. Bulnaev
The source of fluorine from epithermal fluorite deposits, and the character of its evolution

Proceeding from the conception of mantle nature of the fluorine source and the element removal by the basaltic melt into the Earth’s upper strata, it is shown as exemplified by the fluorite deposits of the world-largest Central Asian fluorite-bearing province that the fluorine-enriched fluids could have their origin in the Earth’s lower strata as a result of differentiation of the fluorine-bearing basic magma. Magmatic fluids containing NаF, КF, НF, СО2, Н2О, Сl, and some other components caused anatectic melting of crustal matter at a higher level. The formation of hydrothermal solutions is related to crystallization differentiation or liquation of the incipient granitic magma; the former produced epithermal fluorite deposits at a distance from the intrusive bodies.

L. G. Filimonova, A. V. Chugaev
The role of basite matter and host rhyolites in the formation of the pre-ore postmagmatic minerals of the Dukat ore field, Northeast Russia

The study of chemical composition and variations in the 87Sr/86Sr ratio in postmagmatic minerals and host rhyolites of the unique Au-Ag Dukat ore field indicated that the minerals formed from heterogeneous hydrothermal solutions in reducing conditions of the propylitic facies, and basite matter took part in the chemical composition of the early pre-ore portions of the postmagmatic hydrothermal solution. The evolution of the ore-bearing system proceeded with the temperature dropping from 350 to 250ОС at the early stage of its development. Fe, Mn, Ca, Ti, and Sr contents were reduced, and K, Rb, 87Sr contents increased with the temperature reduction and the quartz-clinozoisite-chlorite and quartz-chlorite–phengite mineral assemblages formation. The host rhyolites were the source of the strontium radiogenic component and lithophyle elements.