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L. F. Simanenko 《Geology of Ore Deposits》2006,48(4):290-303
As indicated by mineralogical, geochemical, and structural-textural data, the base-metal skarn ore at the Partizansky deposit was formed during two stages (base-metal skarn and silver-sulfosalt), which were separated by intrusion of basaltic dikes. The bulk of the base-metal ore was deposited at the first stage, which comprises four sequential mineral assemblages: skarn-silicate, quartz-arsenopyrite, productive galena-sphalerite, and pyrrhotite-pyrite-chalcopyrite. The mineralization of the second stage was mainly confined to the upper margins of orebodies and pertains to the sulfosalt-galena-chalcopyrite assemblage, which was super-imposed on minerals of the first stage. The vertical mineralogical-geochemical zoning of the deposit is telescopic (related to the formation of the late silver-sulfosalt mineralization) and facies (typical of the early skarn and base-metal assemblages). The zoning of the skarn-silicate assemblage is expressed in the metasomatic replacement of skarn by quartz and calcite in the uppermost zone of skarn bodies and is emphasized by variation of the mineral composition throughout the skarn column, for instance, by the distinct updip enrichment of hedenbergite in manganese. The vertical zoning of the productive assemblage is emphasized by variations in the ratio of sphalerite to galena (the Pb/Zn ratio in the ore increases upward from 0.1 to 1), changes in mineral assemblages, and compositional variation of major ore-forming and minor minerals. In particular, galena from the deep levels is extremely enriched in Bi and Ag, while that from the upper levels is almost completely devoid of isomorphic admixtures. Fahlore displays updip enrichment in Sb, Ag, and Fe and corresponding depletion in Cu and Zn. The vertical chemical variations in fahlore are caused by the specific geological setting of ore deposition, the composition of the ore-forming solutions, and the physicochemical conditions of their transportation and ore deposition. 相似文献
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V. P. Simanenko S. V. Rasskazov T. A. Yasnygina A. I. Malinovskii A. A. Chashchin 《Russian Journal of Pacific Geology》2007,1(3):265-275
The Early Cretaceous volcanic rocks of the Mariisky sequence and Early Cenozoic extrusive-vent rocks of Cape Mary are exposed at the northwestern extremity of Schmidt Peninsula, north Sakhalin. In chemical composition, all the rocks are subdivided into four groups. Three groups include the volcanic rocks of the Mariisky sequence, which consists, from bottom to top, of calc-alkaline rocks, transitional calc-alkaline-tholeiite rocks, and incompatible element-depleted tholeiites. These rocks show subduction geochemical signatures and are considered as a fragment of the Moneron-Samarga island arc system. Trace-element modeling indicates their derivation through successive melting of garnet-bearing mantle and garnet-free shallower mantle sources containing amphibole; pyroxene; and, possibly, spinel. The mixed subduction and within-plate characteristics of the extrusive vent rocks of Cape Mary attest to their formation in a transform continental margin setting. 相似文献
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V. P. Simanenko S. V. Rasskazov T. A. Yasnygina L. F. Simanenko A. A. Chashchin 《Russian Journal of Pacific Geology》2011,5(1):26-46
The variations of petrogenic oxides and trace elements have been studied in the Cretaceous volcanic rocks recovered by a deep
borehole from the depth interval of 1253–4011 m on Moneron Island. The volcanic section is subdivided into two complexes:
the Early Cretaceous and Late Cretaceous. The rocks of the Early Cretaceous Complex occur below 1500 m. Chemically, they belong
to low-potassium island arc tholeiites, and their trace element distribution suggests their formation in a suprasubduction
mantle wedge under the influence of water fluids that were subsequently released from subducted sediments and oceanic plate
during the dehydration of subducted sedimentary rocks and oceanic basalts and, finally, mainly from basalts. The Early Cretaceous
basalts from the borehole are interpreted as ascribing to the frontal part of the Moneron-Samarga island arc system. The volcanic
rocks of the Late Cretaceous Complex are situated at depths above 1500 m. They also were formed in a suprasubduction setting,
but already within the East Sikhote-Alin continental-margin volcanic belt that was initiated after the accretion of the Moneron-Samarga
island arc system to the Asian continent. The island-arc section of the Moneron borehole contains basaltic andesite dikes,
which are geochemically comparable with the Early-Middle Miocene volcanic rocks of Southwestern Sakhalin. 相似文献
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Alexander I. Malinovsky Vladimir V. Golozoubov Vladimir P. Simanenko Ludmila F. Simanenko 《Island Arc》2008,17(3):285-304
Abstract The Kema terrane is a suite of Barremian(?)–Aptian to Albian volcano-sedimentary rocks of Sikhote–Alin that are interpreted as deposits of the back-arc basin of the Moneron–Samarga island-arc system. Compositional features of the different-type deposits indicate a near-slope depositional environment influenced by volcanic processes. Studies of slump fold orientation testify to the accumulation of material from southeast to northwest by gravitational sliding. Compositional characteristics of terrigenous rocks suggest the major provenance for detrital material was an ensialic volcanic island arc. Petrochemical characteristics of basaltic rocks indicate that the formations studied were confined to the back part of the arc. 相似文献
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N. N. Kruk V. P. Simanenko V. V. Golozubov V. P. Kovach V. G. Vladimirov S. A. Kasatkin 《Geochemistry International》2014,52(3):229-246
The paper presents geological, geochemical, and isotopic data on metamorphic rocks in the Anuy block (dome) in the Northern Sikhote-Alin and the surrounding sedimentary rocks of the Samarka accretionary prism. The geochemistry and isotopic composition of the amphibolite-facies metamorphic rocks (variably migmatized gneisses and crystalline schists) in the Anuy block and unmetamorphosed Jurassic-Cretaceous sediments surrounding the block are proved to be similar. All of them corresponded to the erosion products of the transitional-type crust (mature island arcs and active continental margins), have similar major- and trace-element compositions, and Nd model ages of 1.25–1.4 Ga. The geochemistry and isotopic parameters of metapelites in the Anuy block are principally different from those of analogous rocks in the Khanka Massif (the latter rocks are erosion products of the mature crust and have a Nd model age of 1.7–1.9 Ga). The metabasites, which are found as beds and lenses in gneisses and crystalline schists in the Anuy block and among sedimentary rocks surrounding the block, have a composition corresponding to oceanic basalts of the N- and E-MORB types. Based on the synthesis of geological, geochemical and isotopic data it was suggested that the Anuy block could be not a fragment of the basement of an ancient continent (as was believed previously) but rather a complex of the Early Cretaceous granite-metamorphic core of the Cordilleran type. 相似文献
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A. I. Malinovsky V. V. Golozubov V. P. Simanenko 《Lithology and Mineral Resources》2005,40(5):429-447
Based on structure, mineralogy, petrography, and geodynamic setting of sedimentation, Barremian(?)-Albian terrigenous rocks in the Kema terrane (Eastern Sikhote Alin) are interpreted as back-arc rocks of the Moneron-Samarga island-arc system. The composition of terrigenous rocks indicates that an ensialic volcanic island arc, the basement of which was composed of the oceanward-advancing continental crust fragment, served as the main source of clastic material. Genetic features of rocks suggest their formation in the lower zone and near the foothill of submarine slope, as well as in adjacent areas of the basin plain. Accumulation of the thick gravitational sequence in the rear zone of the island arc was accompanied by active volcanic processes. 相似文献
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L. F. Simanenko 《Russian Journal of Pacific Geology》2007,1(2):144-152
The localization and chemical composition of the galena from the Partizansky base metal-skarn deposit have been studied in the Second Contact ore body and Bol’nichnaya ore lode. The Partizansky deposit was formed during two stages: base metal-skarn and silver-sulfosalt. Much of the galena was deposited with the productive galena-sphalerite assemblage at the first stage. The galena of the productive stage of the Second Contact body shows wide variations in trace element composition. The galena from the root zone of the ore-bodies (the level of ?135 m) is characterized by steady high contents of economically important isomorphic and mechanical admixtures of bismuth and silver. The galena from the middle levels is almost devoid of isomorphic admixtures and occasionally contains fine inclusions of Ag-tetrahedrite. The high silver (and stibium) contents in the galena from the uppermost horizon (the level of +285 m) are mainly related to mineral inclusions of diverse silver minerals of the late silver-bearing assemblage. The galena from the Bol’nichnaya lode over a large depth interval has elevated contents of isomorphic silver and bismuth, with abundant inclusions of native bismuth. 相似文献