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The meta-analysis was used to summarize the results of previously performed studies on variability of 45 single-nucleotide polymorphism loci and 13 microsatellite loci in Asian sockeye salmon Oncorhynchus nerka populations from the eastern coast of Kamchatka and Chukotka. Allelic frequencies of both types of markers were analyzed using congruent statistical approaches in 53 sample sets from 13 sockeye salmon reproduction watersheds on the west coast of the Bering Sea and the western Pacific Ocean. The spatial structure of the species in considered part of its distribution range was assessed and four major regional population complexes were identified: the Koryak Plateau and Chukotka, the Karaginsky Gulf, the Kamchatka River Basin, and southeastern Kamchatka. The formation of the geographic structure of the sockeye salmon on the Asian Pacific coast is associated with the history of colonization of the region by the species and its adaptation to reproductive conditions in the river and lake-river systems of eastern Kamchatka and Chukotka. [ABSTRACT FROM AUTHOR]

The results of a study of calcareous nannofossils found for the first time in the lower part of the Stolbovaya Group of the Kamchatsky Mys Peninsula in Eastern Kamchatka are presented. Two assemblages of different age are identified, with one assigned to the Upper Cretaceous and the other to the Paleogene (not older than the Lutetian Stage of the Middle Eocene). These data make it possible to refine the age of terrigenous–tuffaceous sequences in the lower part of the Stolbovaya Group, which are poor in organic remains. [ABSTRACT FROM AUTHOR]

Zoned plutons, composed of dunites, pyroxenites, and gabbroic rocks, have been referred to as the Ural-Alaskan type complexes (UA-complexes) and occur in numerous paleo-arc settings worldwide. Many of these complexes are source rocks for economic placers of platinum-group metals. Thus, it is important to understand how UA-complexes form and the origin and behavior of platinum-group elements (PGEs). It is widely assumed that the UA-complexes result from differentiation of supra-subduction high-Ca high-Mg sub-alkaline magmas. However, there is a lack of direct evidence for the existence and differentiation of such magmas, mainly because cases of UA-complexes being spatially and temporally linked to co-genetic volcanics are unknown. We studied an UA-complex from the Tumrok range (Eastern Kamchatka) where a dunite-clinopyroxenite-gabbro assemblage is spatially and temporary related to high-Ca volcanics (i.e., picrites and basalts). Based on the mineral and chemical composition of the rocks, mineral chemistry, and composition of melt inclusions hosted within rock-forming minerals, we conclude that the intrusive assemblage and the volcanics are co-genetic and share the same parental magma of ankaramitic composition. Furthermore, the compositions of the plutonic rocks are typical of UA-complexes worldwide. Finally, the rocks studied exhibit a full differentiation sequence from olivine-only liquidus in picrites and dunites to eutectic crystallization of diopside or hornblende, plagioclase, and K-Na feldspar in plagio-wehrlites and gabbroic rocks. All these results make the considered volcano–plutonic complex a promising case for petrological studies and modelling of UA-complex formation. [ABSTRACT FROM AUTHOR]

New U‒Pb (LA-ICP-MS) geochronological data have been obtained on accessory zircons from granodiorites and on detrital zircons from stream-sediment samples from the Shipunsky massif in the Eastern Kamchatka region. The age of accessory zircons from amphibole–biotite granodiorites has been estimated at 49–44 Ma. Detrital zircons have the Late Paleocene–Early Eocene age from ~57 to ~49 Ma. Based on the geological and geochronological data, the massif was formed in two stages: a gabbroid intrusion (56‒51 Ma) and the quartz diorite-granodiorite intrusion (49‒44 Ma). In terms of the petrographic and geochemical characteristics of the Upper Cretaceous–Eocene volcanic rocks in the Shipunsky Peninsula and granitoids in the Shipunsky massif, they were formed in the suprasubduction setting. The Shipunsky granitoids belong to the I-type granites. The Shipunsky massif was formed as a part of the Kronotsky intraoceanic paleoarc during the Paleocene–Eocene in two stages. The southern segment of the Kronotsky paleoarc collided with the Kamchatka continental margin and the deformed rocks of this massif were brought to the surface. [ABSTRACT FROM AUTHOR]

The sympatric complex of the northern Dolly Varden Salvelinus malma from the basin of Lake Azabachye is represented by four forms with a narrow long-term trophic specialization. Lake–river predators feed mainly on three-spined stickleback Gasterosteus aculeatus. Lake–river benthivorous are differentiated into two trophic groups; one of them (group G) feeds on amphipods and the other (group A) consumes mollusks (Mollusca) and caddis fly larvae (Trichoptera). Brook chars feed on amphibiotic insects (Insecta). The long-term food segregation of Dolly Varden forms is confirmed by differences in the degree of infection by parasites and in the ratios of stable isotopes, 15N/14N and 13C/12C, in the muscles. The indicator parasites are Eubothrium salvelini and Dibothriocephalus spp. for lake–river predators, Cystidicola farionis and Crepidostomum metoecus for lake–river benthivorous of group G, Diplostomum spp. for lake–river benthivorous of group A, and Salmonema ephemeridarum and Cucullanus truttae for brook chars. Predators and benthivorous of group G are characterized by high values of the 15N/14N ratio in the muscles, benthivorous of group A by high 13C/12C values, and brook chars by low values of 15N/14N and 13C/12C. Lake–river predators and benthivorous live together and are distributed throughout the lake and lake channel; brook chars inhabit tributaries. The sympatric complex of S. malma in the basin of Lake Azabachye is the second most diverse complex after the char complex in Lake Kronotskoe. [ABSTRACT FROM AUTHOR]

Zoned plutons, composed of dunites, pyroxenites, and gabbroic rocks, have been referred to as the Ural-Alaskan type complexes (UA-complexes) and occur in numerous paleo-arc settings worldwide. Many of these complexes are source rocks for economic placers of platinum-group metals. Thus, it is important to understand how UA-complexes form and the origin and behavior of platinum-group elements (PGEs). It is widely assumed that the UA-complexes result from differentiation of supra-subduction high-Ca high-Mg sub-alkaline magmas. However, there is a lack of direct evidence for the existence and differentiation of such magmas, mainly because cases of UA-complexes being spatially and temporally linked to co-genetic volcanics are unknown. We studied an UA-complex from the Tumrok range (Eastern Kamchatka) where a dunite-clinopyroxenite-gabbro assemblage is spatially and temporary related to high-Ca volcanics (i.e., picrites and basalts). Based on the mineral and chemical composition of the rocks, mineral chemistry, and composition of melt inclusions hosted within rock-forming minerals, we conclude that the intrusive assemblage and the volcanics are co-genetic and share the same parental magma of ankaramitic composition. Furthermore, the compositions of the plutonic rocks are typical of UA-complexes worldwide. Finally, the rocks studied exhibit a full differentiation sequence from olivine-only liquidus in picrites and dunites to eutectic crystallization of diopside or hornblende, plagioclase, and K-Na feldspar in plagio-wehrlites and gabbroic rocks. All these results make the considered volcano–plutonic complex a promising case for petrological studies and modelling of UA-complex formation.

New data on the fission track ages of apatite detrital grains from Eocene–Miocene deposits of different ages in the Kronotskii Peninsula and the Tyushevka (Tyushevsky) Basin, Eastern Kamchatka are given. The data obtained give us grounds to distinguish three age groups of apatite grains: 31 ± 5, 11–15, and 6–9 Ma. The exhumation ages of sedimentary complexes containing the studied apatite grains are compared with the times of the main tectonic events in Eastern Kamchatka. It is concluded that the collision processes continued from the Oligocene to the Late Miocene. [ABSTRACT FROM AUTHOR]

The measurement data on the Kamchatka Canyon, including the block diagram, a set of echograms, the longitudinal profile of the canyon, and the bathymetric map, and the continuous seismoacoustic profiling data (CSP) has been reinterpreted. The study covers the shelf and the upper and middle parts of the continental slope. Regional gas-saturated strata have been discovered in the Cenozoic cover of the shelf and the continental slope, as well as in the block landslides of the sedimentary cover on the left (~55 km long, the western slope of the Kamchatka Cape) and right (more than 25 km long, the Kamchatka river delta front) sides of the canyon. Hanging landslides on the left side are associated with a 100–150 m increase in the depth of the canyon. On the middle slope, there is a large (28 km long) block landslide and its almost compensated paleochannel. The sub-latitudinal turn and the displacement of the canyon mouth to the north by 70 km is related to uplifting of the ridge-barrier in the Middle Pleistocene – Holocene. Based on the measurement and CSP data, it becomes possible to contour landslides on the sides of the Kamchatka Canyon, select the most hazardous locations (hanging landslides on the upper slope) for numerical modeling of potential landslide-related tsunami, and develop recommendations pertaining to construction of a new international sea port in the town of Ust-Kamchatsk.

The growth, order of anlage, and features of transitive stages of skeletal elements (cranial bones and serial structures: teeth, gill rakers, fin rays, pterigyophores, vertebrae muscles, predorsalia, and scales) in were studied in pre-larvae, larvae, and fingerlings of the nose char (N1-form), endemic lakustrine-riverine form of the Dolly varden Salvelinus malma complex of the Lake Kronotskoe, reared in the laboratory at a constant temperature. A comparative analysis of the early ontogenesis of sympatric species of nose char and white char of the Lake Kronotskoe evidences on a high similarity in the growth rate and development of the two forms, differing by the body length of free embryos and the larvae coloration. [ABSTRACT FROM AUTHOR]

Growth, sequences of anlage, and special traits of transient states are investigated in skeletal elements (skull bones and serial structures—teeth, gill rakers, fin rays and pterygiophores, vertebral centra, predorsalia, scales) in prolarvae, larvae, and fry of endemic lacustrine form Dolly varden Salvelinus malma сomplex from Lake Kronotskoe in small-mouth char grown in a laboratory at constant temperature. A high individual variation of growth rate, osteogenesis, and head profile of small-month char larvae is observed demonstrating a recent, in relation to other endemic Kronotskoe Lake forms, formation of this deep-water lacustrine morphotype. Comparative analysis in early development of sympatric small-mouth and white char indicated the origin of the more warm-water, small-mouth char from the cold-water white char. [ABSTRACT FROM AUTHOR]

Information on stone cockscomb Alectrias alectrolophus diet in Avacha Bay (eastern Kamchatka) are presented, and seasonal, local, age, and interannual changes in the composition of its food are considered. This species is benthophagus, so the main objects in Avacha Bay are Amphipoda. [ABSTRACT FROM AUTHOR]

Abstract Contents of platinum group elements (PGE—Os, Ir, Ru, Rh, Pt, and Pd) and rhenium in basalts of different geochemical types from the ophiolite complex of the Kamchatsky Mys Peninsula have been determined by the isotope dilution-mass spectrometry method. The total contents of PGE in different basalts are commensurate (1.4-3.6 ppb), but the element ratios vary considerably. A specific feature of the rocks is the low degree of PGE fractionation (Pd/Ir = 0.9-6.6, Pt/Pd = 1.0-7.3), which makes them similar to the Hawaiian tholeiitic basalts and picrites. The most fractionated PGE pattern is observed for alkali basalt (Pd/Ir = 6.6), and the least fractionated one, for E-MORB (Pd/Ir = 1.7). The similarity of the PGE patterns of basalts of different geochemical types suggests their similar mantle sources. We propose a model explaining the geochemical features of the basalts of the Kamchatsky Mys ophiolite complex by an impurity of the Earth's core material in the plume source. The Ir/Pd-Ru/Pd and Pd/10-Ir-Ru discrimination diagrams can be used to identify enriched (plume) basalts based on their PGE content. [ABSTRACT FROM AUTHOR]

Abstract: The growth, the sequence of formation, and the features of the transitive states of skeletal elements (cranial bones and serial structures, such as teeth, gill rakers, fin rays and pterygiophores, vertebral bodies, predorsalia, and scales) have been studied in prelarvae, larvae, and fingerlings of the lacusrtrine-riverine morphs of the white charr Salvelinus malma complex from Lake Kronotskoe, Eastern Kamchatka, reared in a laboratory at a constant temperature and collected in the Uzon River, at a spawning ground and downstream. A comparative analysis of osteogenesis features in white charr and the original morph, the Northern Dolly Varden Salvelinus malma malma, has been carried out. A high variability in the rate of growth and development of white charr is noted. A delay in calcification of skeleton in prelarvae and a late onset of scale formation (at the end of the second and the beginning of the third year of life) and first annulus in otoliths (by the third year of life) have been revealed. The results indicate the high specialization of early ontogenesis in white charr, a fish endemic to Lake Kronotskoe. [ABSTRACT FROM AUTHOR]

Gas chromatography and gas chromatography-mass spectrometry data on oils from wells and seeps in the Eastern Kamchatka Basin indicate that, according to their composition and the distributions of biomarker molecules, these oils can be classified into three groups, which differ in the composition of the parent organic matter, litho-facies sedimentation conditions, and catagenetic transformations. Oils from the wells were determined to be produced by organic matter of the sapropel type of marine facies in the main oil window (MC2). Condensate from the natural seep was generated at higher catagenesis grades (MC2-3) by organic matter of the sapropel-humus type of littoral facies. Uzon oil shows are demonstrated to be formed in a continental environment by organic matter of the humus-sapropel type and were not genetically related to oil from the Paleogene-Neogene source rocks of the Bogachevka Formation. [ABSTRACT FROM AUTHOR]

Data on algoflora of the sea water area of Starichkov Island (Eastern Kamchatka) - Nature Monument of the regional significance - are presented including annotated species list of marine algaemacrophytes with information on their fertility and distribution. The list was complied taking into account new data on systematics of algae and enlarged with the species previously unknown from the Pacific coast of Kamchatka: Acrochaete geniculata (Gardn.) OKelly, Pseudulvella prostrata (Gardn.) S. et G. The area of some already known species is extended: Phycodrys valentinae Seliv. et Zhigad., Erythrocladia irregularis Rosenv., Palmaria mollis (S. et G.) Van der Meer et Bird, Acrochaetium parvulum (Kylin) Hoyt. The significance of Starichkov Island for conservation of the biodiversity of Kamchatka is noted.

The available lithological and paleontological data are used to characterize key Cenozoic marine sections in two lithological-facies zones (Kamchatskii Mys Peninsula and southern Valaginskii Range) of the poorly investigated Eastern Kamchatka lithotectonic zone with their correlation and reconstruction of depositional environments at the ocean-continent transition during the Paleogene and Neogene. [ABSTRACT FROM AUTHOR]

The data on the species composition and occurrence of the termophilic and Eastern Pacific representatives of ichthyofauna in the Pacific waters off the northern Kuril Islands and eastern Kamchatka in the 20th-21st centuries are provided. Thirty-three species of termophilic and twelve species of Eastern Pacific fish and lampreys from 35 families have been registered during this period in the Pacific waters near the Kuril Islands and Kamchatka. Annual and seasonal dynamics of appearance of some fish species in the surveyed region in 1992-2002 are analyzed. [ABSTRACT FROM AUTHOR]

The metamorphic complexes of eastern Kamchatka exposed on the Khavyven Highland and Karaginsky Island, as well as on the Kamchatka and Ozernoi peninsulas, compose large (up to 1.5 km) elongated blocks spatially associated with ophiolitic peridotite and gabbroic rock bodies (the Khavyven Highland and Karaginsky Island) or make up isolated fragments and blocks among serpentinite melange (the Ozernoi and Kamchatka peninsulas). The degree of metamorphism of the primary rocks varies from the greenschist/amphibolite boundary facies (Karaginsky Island and the Khavyven Highland) to the high-pressure amphibolite facies (the Ozernoi and Kamchatka peninsulas). Our first U-Pb SHRIMP zircon data on the metamorphic and igneous rocks in eastern Kamchatka and the analysis of previous studies testify to two time intervals of the manifestation of metamorphism in the studied region. The first stage of metamorphism (80-75 Ma) coincides with the formation of the ophiolitic gabbro and peridotites (100-70 Ma) that compose the eastern Kamchatka ophiolite zone. The metamorphic rocks of this stage comprise fragments and blocks in the serpentinite melange (the Kamchatka and Ozernoi peninsulas). They are represented by high-pressure (up to 8-10 kb) garnet amphibolites related to the rocks of the ophiolite association (gabbro, basalts, tuffs, and siliceous rocks). The second stage of magmatism and subsequent metamorphism embraces the time interval of 70-50 Ma. This stage is associated with the formation of volcanics of the tholeiitic, calc-alkaline, and subalkaline series, zonal gabbro-peridotite intrusions (70-60 Ma, and metamorphism of moderate pressures (up to 5-7 kb) and temperatures (400-600°C) typical of rock complexes in the Khavyven Highland and on Karaginsky Island (55-50 Ma). According to the new U-Pb zircon isotope data, the most ancient protolith of metamorphic complexes in eastern Kamchatka is represented by the volcanosedimentary rocks of Karaginsky Island (181 ± 1.8 Ma). The age of the protolith of the Khavyven Highland is 100 ± 11 Ma. The age of the zircons from the garnet amphibolites of the Kamchatka Peninsula (77.6 ± 4.6 Ma) corresponds to the evolution period of the ophiolites of the gabbro-peridotite complex. [ABSTRACT FROM AUTHOR]

This paper presents detailed mineralogical and geochemical data on the metamorphosed ferromanganese rocks observed as rare lenticular bodies among the metavolcanics of the Khavyven Highland and Ganal Ridge in Eastern Kamchatka. They are specific porphyry-type banded Mn-garnet and amphibole rocks with large (up to 1–5 mm) magnetite porphyroblasts. In the Khavyven Highland, ilmenohematite is associated with magnetite in the metamorphosed ferromanganese rocks of the greenschist facies. In the Ganal Ridge, magnetite in metamorphosed ferromanganese rocks of the amphibolite facies shows decay structures and contains Mn-ilmenite lamellae surrounded by tiny crystals of ferroaluminous Zn-spinel. Comparison of Fe-Ti oxides in the ferromanganese rocks of the Khavyven Highland and Ganal Ridge shows that metamorphism of these structures differed not only in temperature and pressure levels but also in the oxygen fugacity. The rocks of the Khavyven Highland were metamorphosed under greater oxidizing conditions relative to the analogous rocks of the Ganal Ridge. The garnets in the studied rocks demonstrate progressive zonality from the center to the rims of crystals: the Fe, Mg, and Ca concentrations are increased, while the Mn concentration is decreased. Amphibolites in the ferromanganese rocks of the Khavyven Highland are also characterized by progressive zonality: the crystal cores are composed of Mn-actinolite, whereas the marginal zones consist of Ca-Na amphibole (winchite and less common barroisite), testifying to an increase of temperature, pressure, and oxygen fugacity during metamorphism. The higher-temperature rocks of the Ganal Ridge usually contain Mg-hornblende and tschermakitic hornblende. The specific features of the ferromanganese rocks in Eastern Kamchatka—their lenticular morphology; confinement to volcanic-rich rocks; high contents of iron oxide (up to 20% or more) and manganese oxide (up to 7–10%); higher concentrations of Ni and Cu; and lower concentrations of Ba, Sr, and Pb—allowed us to compare the studied rocks with the ferromanganese crusts of oceanic areas and suggest their sedimentary (hydrogenic) origin in a back-arc basin of island-arc systems of the Pacific-type active continental margin during the abrupt waning of the volcanic activity and intense underwater currents, which promoted the evacuation of the bulk of the lithogenic sedimentary material. [ABSTRACT FROM AUTHOR]

We present new data on marine algae of the South Kamchatka state wildlife sanctuary (Yuzhno-Kamchatskii Zakaznik, Russia), a protected natural area of federal significance. The species list of macrophytic marine algae is accompanied by information on their reproduction and distribution. This list updates the taxonomy and expands a previous list, with many new species, including 2 species previously unknown from the Pacific coasts of Russia ( Colaconema endophyticum, Acrochaetium plumosum), 2 species new to the coasts of Kamchatka ( Colaconema daviesii and Acrochaete geniculata), and 11 species recorded for the first time from the area studied ( Erythrocladia irregularis, Palmaria hecatensis, Palmaria mollis, Meiodiscus concrescens, Crossocarpus lamuticus, Cirrulicarpus ruprechtianum, Rhodomela sibirica, Urospora elongata, Zygomitus reticulatus, Acrochaete ramosa, Acrochaete pterosiphoniae) (Nagai) Zhigadlova, comb. nov. (= Entocladia pterosiphoniae). The importance of the wildlife sanctuary for the conservation of biodiversity in Kamchatka is noted. [ABSTRACT FROM AUTHOR]

The geological, geochemical and mineralogical data of dismembered ophiolites of various ages and genesis occurring in accretionary piles of the Eastern Peninsulas of Kamchatka enables us to discriminate three ophiolite complexes: (i) Aptian–Cenomanian complex: a fragment of ancient oceanic crust, composed of tholeiite basalts, pelagic sediments, and gabbroic rocks, presently occurring in a single tectonic slices (Afrika complex) and in olistoplaques in Pikezh complex of the Kamchatsky Mys Peninsula and probably in the mélange of the Kronotsky Peninsula; (ii) Upper Cretaceous complex, composed of highly depleted peridotite, gabbro and plagiogranite, associated with island arc tholeiite, boninite, and high-alumina tholeiitic basalt of supra-subduction origin; and (iii) Paleocene–Early Eocene complex of intra-island arc or back-arc origin, composed of gabbros, dolerites (sheeted dykes) and basalts produced from oceanic tholeiite melts, and back-arc basin-like dolerites. Formation of the various ophiolite complexes is related to the Kronotskaya intra-oceanic volcanic arc evolution. The first ophiolite complex is a fragment of ancient Aptian–Cenomanian oceanic crust on which the Kronotskaya arc originated. Ophiolites of the supra-subduction zone affinity were formed as a result of repeated partial melting of peridotites in the mantle wedge up to the subduction zone. This is accompanied by production of tholeiite basalts and boninites in the Kamchatsky Mys segment and plagioclase-bearing tholeiites in the Kronotsky segment of the Kronotskaya paleoarc. The ophiolite complex with intra-arc and mid-oceanic ridge basalt geochemical characteristics was formed in an extension regime during the last stage of Kronotskaya volcanic arc evolution. [ABSTRACT FROM AUTHOR]

Bottom communities of Potamogeton filiformis, Zostera marina+ Z. japonica+ Macoma balthica, Enteromorpha prolifera, and a stony block–boulder intertidal community were distinguished in Semyachik Lagoon. The macrobenthos associated with these communities is described. Generally, the biomass and occurrence frequency indices of the macrozoobenthic communities of the lagoon are an order of magnitude lower than those of macrophytobenthic communities (Kafanov, Plekhov, 1998); therefore, they do not play a significant role in bottom community structure. With the exception of the stony block–boulder intertidal community, their spatial distribution is entirely determined by the distribution of underwater vegetation, which is completely controlled by the geomorphological and hydrological features of the lagoon. [ABSTRACT FROM AUTHOR]