Analysis of the sections of Cretaceous deposits in the Western Sikhote-Alin and the Lower Amur region suggests two stages in Cretaceous sedimentation: (1) Berriasian–Valanginian stage for the Gorinskaya, Priamurskaya and Priussuriyskaya structural-formational subzones (SFS) of the Western Sikhote-Alin structural-formational zone (SFZ); and (2) Aptian–Albian stage for the Priamurskaya SFS and Albian–Cenomanian stage for the Chayatynskaya SFS of the Western Sikhote-Alin SFZ. The Berriasian–Valanginian deposits of the Western Sikhote-Alin and the Lower Amur region are predominantly sandy sediments, in contrast to the coeval deposits of the Luzhkinskaya SFS of the Eastern Sikhote-Alin SFZ, where they are mainly silty–argillaceous in composition and contain basalt flows at the base of the section. Geochronological studies showed that the Berriasian-Valanginian deposits of the Komsomolskaya Group of the Gorinskaya and Priamurskaya SFS are widespread only within the western “band” adjacent to the Badzhal–Gorinskaya SFZ of the Sikhote-Alin orogenic belt and to the Ulbanskaya SFZ of the Mongol–Okhotsk orogenic belt that extends from the Ussuri lower reaches in the south to the Sakhalin Gulf coast in the north. Studies of source types indicate the formation of Berriasian–Valanginian deposits in a subcontinental setting. We believe that since the deposits contain outliers of Jurassic siliceous rocks, they are mainly of accretionary nature. As for their tectonic nature, we consider these deposits to be a terrane, as they formed in subequatorial latitudes (10°–18° N) and then drifted northward for more than 4000 km to their present-day position. We propose calling this complex the Gorin terrane of the Berriasian–Valanginian accretionary wedge. The Berriasian–Valanginian deposits of the Priussuriyskaya SFS also display an accretionary nature and were attributed to the Gorin terrane. Since Berriasian–Valanginian deposits of the Priussuriyskaya SFS correlate well with deposits of the Khor-Dalnenskaya SFS of the Central Sikhote-Alin SFZ, we believe that the latter were in the close proximity to the Gorin terrane at that time. The Aptian–Albian deposits of the Priamurskaya SFS and Albian–Cenomanian deposits of the Chayatynskaya SFS overlie with a gap the Berriasian–Valanginian rocks of the Komsomolskaya Group that formed in subequatorial latitudes. In addition, the paleomagnetic studies of volcanogenic rocks of the Cenomanian–Turonian Utitsa Formation, which complete the section of Albian–Cenomanian sediments, showed its autochthonous position. This suggests that the Aptian–Albian and Albian–Cenomanian deposits were formed between the latitudes at which the Berriasian–Valanginian deposits of the Komsomolskaya Group accumulated and the latitude of development of the Cenomanian–Turonian Utitsa Formation. Thus, both the Aptian–Albian and Albian–Cenomanian deposits, as well as Berriasian–Valanginian, should be considered a terrane. Thus, the provenance area of the Aptian–Cenomanian sediments significantly changed and became mainly a volcanic arc. The structure of these deposits clearly indicates the structure of an accretionary wedge. Moreover, the biostratigraphic studies demonstrated a close spatiotemporal link between the Albian–Cenomanian sedimentary complex and the accretionary complex of the Kiselevka–Manoma terrane. Based on this, we propose distinguishing the Aptian–Cenomanian sedimentary complex as a separate Chayatyn terrane of the Aptian–Cenomanian accretionary wedge.

Приведены результаты комплексных исследований терригенных пород хабаровского аккреционного комплекса Сихотэ-Алиня. Установлено, что в обломках юрских и пермско-триасовых песчаников доминирует слабоокатанный и слабосортированный материал преимущественно из местных источников сноса. Обломочная часть пород представлена в основном кварцем, в меньшем количестве полевыми шпатами и обломками пород. Песчаники характеризуются повышенными содержаниями кремнезема, умеренной глиноземистостью, невысокими концентрациями фемических элементов и кальция, умеренными содержаниями щелочей при значительных вариациях K/Na отношения. Как для юрских, так и для пермско-триасовых пород типичны пониженные в сравнении с PAAS содержания LILE, РЗЭ, в меньшей степени HFSE и отрицательные значения параметра ɛNd(T). Модельный Nd возраст юрских песчаников варьирует от 1.36 до 1.71 млрд лет, пермско-триасовых — от 1.14 до 1.35 млрд лет. Большая часть популяции детритовых цирконов имеет позднепалеозойско-раннемезозойский возраст, примерно 25 % — более древний (до палеопротерозоя). Изученные песчаники являются преимущественно породами первого цикла выветривания (петрогенными), образованными при размыве магматических пород кислого состава. Синтез полученных данных позволяет считать, что главным источником кластического материала для мезозойских осадочных пород служили геологические комплексы северной части Бурея-Ханкайского супертеррейна (Буреинский и Малохинганский блоки), а также, возможно, восточной части Монголо-Охотского пояса. Хабаровский террейн не претерпел значительных перемещений по сдвигам системы Тань Лу и является «автохтонным» блоком в современной структуре Сихотэ-Алиня. The results of comprehensive studies of terrigenous rocks of the Khabarovsk Sikhote-Alin accretionary complex are presented. It is established that the fragments of Jurassic and Permian–Triassic sandstones are dominated by poorly rounded and poorly separated material mainly from local provenance areas. The detrital part of the rocks is mainly represented by quartz, in a smaller amount by feldspar and rock fragments. Sandstones are characterized by high silica content, moderate alumina content, low concentrations of femic elements and calcium, moderate alkali content with significant varia-tions in the K/Na ratio. Both Jurassic and Permian–Triassic rocks are typically characterized by reduced contents of LILLE, REE, to a lesser extent HFSE and negative values of the ɛNd(T) parameter – compared to PAAS. The model Nd age of Jurassic sandstones varies from 1.36 to 1.71 Ga, Permian–Triassic — from 1.14 to 1.35 Ga. Most of the detrital zircon population is of late Paleozoic–early Mesozoic age, approximately 25% are older (pre-Paleoproterozoic). The studied sandstones are mainly rocks of the first cycle of weathering (petrogenic), formed during the erosion of igneous rocks of felsic composition. The synthesis of the obtained data suggests that the main source of the cluster material for the Mesozoic sedimentary rocks was the geological formations of the northern part of the Bureya-Khanka superterrane (Bureya and Malokhingan blocks), as well as, possibly, the east-ern part of the Mongol-Okhotsk belt. The Khabarovsk terrane has not drifted significantly along the Tan Lu stike-slip system and is an “autochthonous” block in the present-day struc-ture of Sikhote-Alin.

The results of comprehensive studies of terrigenous rocks of the Khabarovsk Sikhote-Alin accretionary complex are presented. It is established that the fragments of Jurassic and Permian-Triassic sandstones are dominated by poorly rounded and poorly separated material mainly from local provenance areas. The detrital part of the rocks is mainly represented by quartz, in a smaller amount by feldspar and rock fragments. Sandstones are characterized by high silica content, moderate alumina content, low concentrations of femic elements and calcium, moderate alkali content with significant variations in the K/Na ratio. Both Jurassic and Permian-Triassic rocks are typically characterized by reduced contents of LILE, REE, to a lesser extent HFSE and negative values of the epsilon(Nd)(T) parameter - compared to PAAS. The model Nd age of Jurassic sandstones varies from 1.36 to 1.71 Ga, Permian-Triassic - from 1.14 to 1.35 Ga. Most of the detrital zircon population is of late Paleozoic-early Mesozoic age, approximately 25% are older (pre-Paleoproterozoic). The studied sandstones are mainly rocks of the first cycle of weathering (petrogenic), formed during the erosion of igneous rocks of felsic composition. The synthesis of the obtained data suggests that the main source of the cluster material for the Mesozoic sedimentary rocks was the geological formations of the northern part of the Bureya-Khanka superterrane (Bureya and Malokhingan blocks), as well as, possibly, the eastern part of the Mongol-Okhotsk belt. The Khabarovsk terrane has not drifted significantly along the Tan Lu stike-slip system and is an "autochthonous" block in the present-day structure of Sikhote-Alin.

The paper presents the results of structural, geochemical, magnetic and paleomagnetic studies on Mesozoic rocks of the Nilan terrane, which from the north flank on the Paleozoic rocks of the Paukan block (52.0°N, 135.6°E). Jurassic and Triassic (?) multiple disturbance deposits of the terrane were found to be fragments of the Middle-Late Jurassic accretionary complex with accumulations of older oceanic rocks varying in thickness and the oceanic plate with completely destroyed stratigraphy. Basic and intermediate volcanic rocks hosted within Jurassic and Triassic (?) sedimentary rocks of the terrane are of oceanic origin. Based on geochemical and paleomagnetic data, it is assumed that the volcanic rocks formed near the equator in geodynamic settings of mid-ocean ridge and intraplate ocean islands.

The Ulban terrane composed of a thick sedimentary series of Jurassic clastic deposits is located at the junction of the Mongol-Okhotsk and Sikhote-Alin orogenic belts. The results of studying the deposits assigned to the Middle Jurassic Elgon Formation are presented. The structure of the sedimentary succession and sedimentological features, which indicate sand-rich turbidite sedimentation in a setting of sandy lobe of turbidite fans or ramps, are considered and illustrated. The paleocurrent directions measured in outcrops and calculated using the anisotropy of the initial magnetic susceptibility suggest the transport of clastic material from western or southwestern sources.

A geochronological study of detrital zircons from sedimentary rocks of the Gorinskaya (91 zircons with concordant ages), Pionerskaya (117 zircons with concordant ages), and Pivanskaya (115 zircons with concordant ages) formations of the Komsomolskaya Group has been carried out. It was found that the 206Pb/238U age of the youngest zircon population is consistent with the stratigraphic age only for the Pivanskaya Formation. For the other two formations, the youngest zircon populations turned out to be significantly younger than their upper stratigraphic limits. New evidence shows that: (1) the age of the “Berriasian–Valanginian” sediments of the Pionerskaya Formation is not older than the Barremian and (2) the age of the “Tithonian–Berriasian” deposits of the Gorinskaya Formation is not older than the Hauterivian. The subdivision of the Komsomolskaya Group into formations is based primarily on lithological criteria. However, since the composition of the formations is very similar, the identical deposits in other Lower Cretaceous sequences of the region could be assigned to other stratigraphic units. Thus, the above conclusion is valid only for the sections we studied.

На основе опубликованных работ сотрудников лаборатории тектоники Института тектоники и геофизики им. Ю.А. Косыгина Дальневосточного отделения Российской академии наук даётся краткий обзор результатов геологических и тектонических исследований типовых объектов юго-восточной части Сибирской платформы, Центрально-Азиатского орогенного пояса и восточной окраины Азии. Представлен краткий обзор основных этапов развития лаборатории. Based on the published works of the researchers from the Laboratory of Tectonics at the Kosygin Institute of Tectonics and Geophysics, Far East Branch, Russian Academy of Sciences, the results of geological and tectonic studies are briefly reviewed, which are focused on the type geological features and entities of the southeastern Siberian platform, the Central Asian orogenic belt, and the eastern margin of Asia. A brief account of the main stages in the development of the Laboratory is provided.

The paper presents the first findings of paleomagnetic studies on Middle Jurassic sedimentary rocks of the Elgon Formation of the Ulban Terrane from the coastal outcrops along the Ulban Bay (53.5° N, 137.7° E). Demagnetization yielded a ChRM component of the pre-folding age. No inclination shallowing effect for the ChRM vector was revealed in sandstone specimens of the Elgon Formation. The paleomagnetic pole coordinates and the paleolatitude at which the studied rocks deposited were calculated: Plat = –34.3 (34.3)°; Plong = 161.2 (341.2)°; dm = 2.7, dp = 5.3, paleolatitude = 0.1° (+2.7°/–2.6°) S. The acquired paleomagnetic data are evidence of the deposition of the rocks of the Ulban Terrane in the Middle Jurassic at the boundary between the Asian paleocontinent and the Paleo-Pacific, which later formed part of the Sikhote Alin Orogenic Belt.

Geochronological dating was performed on the detrital zircons of 20 sedimentary rock samples from the Khabarovsk, Samarka, and Zhuravlevka–Amur terranes in the northern Sikhote-Alin Orogenic Belt to establish that (1) the isotopic 206Pb/238U ages of the youngest detrital zircon populations of two sedimentary rock samples from the Gorin (K1b) and Pioner (K1b-v) formations, as well as one sample from the Svetlorechensk massif (J3t), were significantly younger than the upper limit of the accepted stratigraphic age of these rocks and (2) sedimentary rocks accumulating in the accretionary prisms matrix of the Khabarovsk–Voronezh tectonostratigraphic zone in the Khabarovsk Terrane and turbidites in the Gorin tectonostratigraphic zone pull-apart basin of the Zhuravlevka–Amur Terrane were derived from sources located within the eastern part of the Central Asian Belt. The source of sedimentary rocks accumulating in the turbidite matrix of the accretionary prisms in the Anyui tectonostratigraphic zone of the Samarka Terrane and turbidites in the pull-apart basin of the Koppi–Luzhki tectonostratigraphic zone of the Zhuravlevka–Amur Terrane was found in the North China Craton.

New petrogeochemical data were used to determine conditions for the formation of volcanics and their tectonic position in the area of Lake Udyl’. These rocks were correlated with similar rocks in the region. Volcanics of two genetic types were identified in the area of Lake Udyl’: 1) intraplate oceanic volcanics as part of the accretionary volcanic-siliceous complex (Tithonian-Valanginian-Hauterivian-Barremian) similar to accretionary complexes in other segments of the Kiselevka-Manoma Terrane, and 2) suprasubduction-zone volcanics as part of the island-arc volcanogenic-terrigenous complex (Valanginian-Hauterivian-Aptian-Albian-Cenomanian). A conclusion about the tectonic superposition of complexes of different genesis in the Udyl’ segment is based on synthesis of the new geological and petrogeochemical data, as well as geochronological and paleomagnetic data from previous studies.

This paper presents paleomagnetic data on the Berriasian-Valanginian sandstones of the Gorinskaya and Pionerskaya Formations of the Komsomolskaya Group from the coastal outcrops of the Sakhalin Bay (54.09° N, 140.05° E). Structurally, these rocks belong to the Zhuravlevka-Amur (ZhA) terrane of the Sikhote-Alin orogenic belt. Paleomagnetic studies indicate that these rocks were formed at a latitude of 10°–18° N, which is comparable to paleolatitudes (10° N–4° S) obtained previously from the Berriasian-Valanginian basalts of the Rozhdestvenskaya Formation (Sakhalin Island). The obtained paleolatitude means that after 140 Ma the Zhuravlevka-Amur terrane drifted northward by over 4000 km along the continental margin of Eurasia at an average rate of about 10 cm/year.

The first paleomagnetic and petrochemical data on the Lower Cretaceous sedimentary rocks of the Komsomolsk Series from the Zhuravlevka–Amurian turbidite paleobasin are presented. The rocks are collected in coastal outcrops of Sakhalin Bay (54.09° N, 140.05° E). The studies reveal that (1) the petrochemical characteristics of the sedimentary rocks of the Gorinskaya and Pionerskaya formations (Berriasian–Valanginian) do not contradict the model of their formation in a setting of the transform continental margin; (2) the paleolatitude at which they attained pre-folding paleomagnetic direction (Dec = 303°, Inc = 27°, Ks/Kg = 6.2) was 10–18° N; (3) in the post-Valanginian time, before 95 Ma B.P., the block including these rocks moved northward by 3900–4800 km along the Eurasian transform continental margin at a mean rate of about 10–13 cm/yr.

The results of comprehensive (geological, geochemical, geochronological, and petro- and paleomagnetic) study of the Aptian–Albian rocks of the Kema Terrane and the northeastern Udyl segment of the Kiselevka–Manoma Terrane are presented. The obtained results suggest that the studied volcanogenic–terrigenous complexes of rocks formed in a suprasubduction zone at about the same time (early Albian, 110 Ma ago) at close latitudes but in different island arcs unequally distant from the continent: the complexes of the Kema Terrane at a latitude of 36° ± 6° N in the island arc close to the continent as evidenced by the petro–geochemical characteristics of the volcanites and the presence of ancient zircons in the sediments; and the rocks of the Udyl segment of the Kiselevka–Manoma Terrane at a latitude of 33° ± 5° N in an intraoceanic island arc separated from the volcanic arc of the Kema terrane by an interarc basin, which was wide and deep enough to avoid the influence of the continental source areas in the sediment accumulation zone of the Kiselevka–Manoma Terrane. Based on the conclusions, the geodynamic reconstruction is developed for the formation and history of motions of the studied rock complexes during the oceanic plate movement, their displacement along the transform margin, as well as post-accretionary movements at various distances to the current position with the following coordinates: Udyl 52° N, 140° E; Kema 45°–46° N, 136°–137° E.

The paper presents the results of paleomagnetic and geochronological studies on the Lower Cretaceous sandstones of the Silasa and Kema Formations (Kiselevka-Manoma and Kema terranes, respectively). Source areas of rocks are determined and paleolatitudes at which they formed are constrained. The fact that ages of zircons from sandstones of the studied formations differ essentially suggests that the material from a source area in continental Eurasia was not transported to the deposition area of the Silasa Formation. The reason is that sediments of the Silasa Formation accumulated in the outer island arc zone separated by the fore-arc basin from the inner island arc zone where the material from the continent was transported to the deposition area of the Kema Formation.

New results of dating of detrital zircons from the Kema and Silasa Formations (Albian, Sikhote–Alin Orogenic Belt) permit determination of the provenance sources and geodynamic settings of sediment deposition. The Silasa Formation was deposited in outer island arc settings, separated by a forearc basin from the inner island arc, where the Kema Formation sediments were accumulated. The significant depth and width of the forearc basin hindered input of continent-derived debris to the area of sedimentation of the Silasa Formation.

The results of the paleomagnetic investigation of the sediments pertaining to the Silasinskaya Formation of the Kiselevka–Manoma terrane within the Sikhote Alin orogenic belt are presented. The ancient prefolding magnetization component is revealed: Decs = 271.7°, Incs = 52.2°, Ks = 13.5, and a 95s = 5.1° (positive fold and reversal tests); and the coordinates of the corresponding paleomagnetic pole for ~103 ± 10 Ma are calculated: Plat = 26.3°, Plong = 70.5°, dp = 4.8°, and dm = 7.0°. As a result of this study, the geodynamical settings and paleolatitudes of the formation of three objects in the northern part of Sikhote Alin orogen are established: (a) the Kiselevskaya Formation of the Kiselevka–Manoma terrane was formed 133 Ma ago at 19° N under the seamount condition on the Izanagi Plate; (b) the Silasinskaya Formation of the Kiselevka–Manoma terrane was formed 103 Ma ago at 35° N under the oceanic island arc conditions; and (c) the Utitskaya Formation of the Zhuravlevsk–Amur terrane was formed 95 Ma ago at 54° N in the active continental margin conditions. It is found that the transform continental margin of Eurasia developed in the time interval from 105 to 65 Ma ago in the regime of a left-lateral submeridional shear from 30° to 60° N. The complete attachment of the studied rocks of the Kiselevka–Manoma terrane to the Eurasia’s margin (to the Zhuravlevsk–Amur terrane) occurred at the boundary of 60–70 Ma. Simultaneously, the sense of the displacement in the submeridional shears changed from left-lateral to right-lateral with the formation of pullapart type basins (Lake Udyl’).

The reconstruction of stress fields in the Lower Amur region allowed us to subdivide them into four groups. Two groups are related to the fields of the strike-slip fault type and others to the reverse and normal fault types. As a result of structural analysis, it has been established that the stress fields differ in age and correspond to different stages of deformation. It has been shown that origin and evolution of the Cenozoic basins in the Lower Amur region were related to the paleogeodynamics of the faults, which served as a northeastern continuation of the Tan-Lu Fault System, as well as of the NW-striking faults at the lower reaches of the Amur River. Based on the data obtained, a new model of the origin, formation, and evolution of basins in the Lower Amur region is proposed.

The results of comprehensive geological, petrochemical, and paleomagnetic study of the Cenomanian–Turonian volcanic and sedimentary rocks of the Utitsa Formation are presented. The petrochemical characteristics indicate that the volcanic rocks were formed in a volcanic arc setting with supra-subduction geochemical sources. According to petro- and paleomagnetic study of the volcanic rocks, the paleolatitude of their formation is 53.7° ± 10.8° N and the coordinates of the paleomagnetic pole are Plat = 81.6°, Plong = 208.2°, dp = 10.8, dm = 12.5°. Comparison with the Mesozoic area of the trajectory of apparent migration of the pole of stable Siberia and Eurasia points to the autochtonous position of the Utitsa Formation relative to the Late Cretaceous continental margin. The data on the magnetic structure of the sedimentary rocks of the Utitsa Formation indicate the presence of an ENE–WSW-trending (50°–70°–230°–250°) bottom paleocurrent in the sedimentation basin.