A. A. Soboleva
Russian Academy of Sciences
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by A. A. Soboleva.
Geology | 2011
Elizabeth L. Miller; N. Kuznetsov; A. A. Soboleva; O. V. Udoratina; Marty Grove; George E. Gehrels
U-Pb ages of detrital zircon suites from Paleozoic strata in the Arctic Alaska–Chukotka terrane (AAC), Alexander terrane, northern Sierra terrane, and eastern Klamath terrane of the North American Cordillera suggest an exotic Gondwana or Baltic origin. We evaluate these hypotheses with U-Pb ages of detrital zircon suites from Cambrian–Devonian strata of northern Baltica. Precambrian zircon populations (ca. 0.8–3.0 Ga) from Baltica compare well with similar age detritus in the AAC and Cordilleran terranes, but the amount and age of younger Neoproterozoic and Ordovician–Silurian components are variable. The AAC shares its stratigraphy with Baltica and has the most similar detrital zircon suites. Closing the Arctic places the AAC against the Lomonosov Ridge and the edge of Baltica in pre-Cretaceous time. After the Caledonian orogeny and before the Ural Mountains formed, the Baltica, AAC, and Cordilleran margins shared a Devonian–Carboniferous rift history and became along-strike portions of a Carboniferous–Permian continental margin. This rifting event might have been responsible for the initial separation of Baltica and Caledonian affinity terranes from this margin.
Doklady Earth Sciences | 2011
S. Yu. Orlov; N. B. Kuznetsov; Elizabeth L. Miller; A. A. Soboleva; O. V. Udoratina
The PreUralide-Timanide orogeny is the oldest collision event, which is more or less reliably recorded in the presentday Arctic region (9, 10). This collision was determined by the convergence at the Vendian- Cambrian transition (or in the initial Cambrian) between the Timan-Waranger margin of the Baltica continent, an ancient framework of the East European Platform and the Bolshezemlskaya margin of Arc� tida. The PreUralide-Timanide orogeny was inferred from the study of PreUralide inliers among the Uralide complexes (2, 10, and references therein), the distribution of detrital zircons of corresponding ages in different Arctic areas (1, 2, 13, and references therein), and mostly the analysis of granitoid associa� tions in the northern areas of the Urals and basement of the Pechora basin (6, 8, 9, and references therein). It is known that northern segments of the western Urals and basement of the Pechora basin are intruded by Late Precambrian and Cambrian granites with ages from ~730 to 510 Ma (Fig. 1) (2, 6, 8, 9, and others). By their composition, these granites may be attributed to both subductionrelated and collisional types (6, 9). The ambiguous nature of these rocks hampers limiting the period when subductionrelated tectonic environ� ments gave way to continental collision settings. This means that granites that reflect convergence environ� ments cannot serve as a tool for an accurate age deter� mination for the onset of collision between Baltica and Arctida. This problem requires other independent tools. 1 We suggest to use erosional products of the Pre� Uralide-Timanide orogen that are represented by Upper Precambrian-Lower Paleozoic detrital rocks developed in the northern part of the East European Platform as one such tool. This approach is based on the concept that the composition of allothigenic min� erals constituting detrital rocks as well as their isotopic compositions and ages reflect the corresponding parameters of provenances, i.e., domains that yielded eroded material for detrital rocks. By analogy with recent collision orogens (Alps, Himalayas, and others), we assume that the Pre� Uralide-Timanide orogen represented a mountainous folded structure, which was subjected to intense ero�
Doklady Earth Sciences | 2010
N. B. Kuznetsov; L. M. Natapov; Elena Belousova; U. L. Griffin; S. Y. O’Relly; K. V. Kulikova; A. A. Soboleva; O. V. Udoratina
This report presents the first results of U/Pb dating, isotope-geochemical, and geochemical studies of detrital zircons from the Neoproterozoic clastic rocks of the Southern Timan. Sixty-one zircon grains were treated, including 51 from red-colored sandstones and 10 grains from aleurosandstones of the Djejim Formation of the southern Chetlas-Djejim zone (Djejim-Parma Hill). It was found that the U/Pb-ages of zircons from the rocks of the Djejim Formation, varied from ∼2.97 to ∼1.20 Ga. The studies of microelement composition in 47 grains (of 61 U/Pb isotope ages obtained), on the basis of several empirical regularities found formerly, show that the detrital zircons had originated from “granites” (22 grains), “diorites” (12 grains), or their volcanic analogues, or more rarely, from “syenites” and “basites” (5 and 8 grains, respectively). The Lu/Hf isotope system of zircons allows one to estimate the model ages (TDMC) of the substrate magmatic rocks being parental to the zircons considered. In particular, Archean zircons are characterized by ∼2.84–3.36 Ga model ages of magmaforming rocks. For some of the grains, their model ages (∼2.84 Ga) are close to those of zircons as such (∼2.7–2.8 Ga), which points to the juvenile character of the substrate from which the parent magma of the zircons treated was fused. For Proterozoic (to Middle Riphean) zircons, the Lu/Hf isotope system allows one to estimate the model age of the substrate of their parental rocks within ∼2.00–3.36 Ga, which shows that these rocks were formed under the recycling of the Archean and Early-Proterozoic crust. The ages obtained for detrital zircons, as well as model ages of the substrate of the corresponding parental magmatic rocks, are quite comparable to the age of crystalline complexes of the ancient framework of the East European Platform (EEP), formed in the course of the Archean, Early-Proterozoic, and Early-Middle Riphean tectonomagmatic events. This permits us to conclude that the Neoproterozoic detrital complexes of the Timan were formed owing to the erosion of earlier Neoproterozoic and Early Precambrian complexes constituting the Neoproterozoic Baltica continent, presenting complexes of the passive margin of this continent. A variety of ages of detrital zircons from sandstones and aleurosandstones from the Djejim Formation of Djejim-Parma Hill, and of the estimates of magmatic rocks parental to these zircons, may be characterized as a Baltic Provenance signal.
Doklady Earth Sciences | 2011
N. B. Kuznetsov; S. Yu. Orlov; Elizabeth L. Miller; A. V. Shazillo; A. V. Dronov; A. A. Soboleva; O. V. Udoratina; George E. Gehrels
The first results of U/Pb isotopic dating (LA ICP MS) of detrital zircons from sands from the Middle Cambrian Sablinka Formation, Upper Cambrian Ladoga Formation, Low Ordovician Tosna Formation, and calcareous sands from Syas’ Formation (Sargaevskii horizon of the Upper Frasnian) from Baltica-Ladoga Glint (BLG) of the Southern Ladoga area are presented. The obtained ages of detrital zircons span the intervals 492.7 ± 5.1-3196.4 ± 5.1 Ma (Sablino Formation); 577.9 ± 7–2972.6 ± 13.4 Ma (Ladoga Formation); 509.4 ± 8.5–3247.6 ± 10.1 Ma (Tosna Formation); 451.1 ± 14.7–2442.2 ± 6.9 Ma (Syas’ Formation). A comparison of the obtained isotopic ages of detrital zircons to ages of crystalline complexes composing the Kola-Karelian, Svecofennian, and Sveconorwegian domains of Baltic Shield and Pre-Uralian-Timanian structures of Subpolar and Polar Urals and basement of Pechora Basin was carried out. It is proposed that the Middle Paleozoic sedimentary basin accumulated Upper Frasnian rocks of Syas’ Formation. The basin ranged northward from the present-day BLG and occupied the eastern part of the Baltic Shield.
Doklady Earth Sciences | 2012
A. A. Soboleva; N. B. Kuznetsov; Elizabeth L. Miller; O. V. Udoratina; George E. Gehrels; T. V. Romanyuk
The most modern and the most selfconsistentideas about the structure of the Uralian thrustfold beltare reported in [1]. This book develops insights byN.P. Kheraskov [2] who believed that there are two agegroups whose units are widespread in the Urals; theyare the Uralides and the ProtoUralides (below, PreUralides).
Doklady Earth Sciences | 2009
N. B. Kuznetsov; L. M. Natapov; Elena Belousova; U. L. Griffin; Suzanne Y. O’Reilly; A. A. Soboleva; K. V. Kulikova; O. V. Udoratina; A. A. Morgunova
The upper horizons of the Earth’s crust in the eastern and northeastern framing of the East European platform consist of two units. The upper unit is made up of Late Precambrian and younger (mainly sedimentary) complexes; the lower unit consists of Late Precambrian complexes termed in total as Pre-Uralides‐Timanides [1, 2]. The Pre-Uralides‐Timanides form uplifts and anticlinoriums extending as an uninterrupted chain along the western slope of the Urals. They are also exposed at Timan and the Kanin Nos peninsula. Age analogs of the Pre-Uralides‐Timanides complexes occur as fragments on Kildin Island, in the Rybachii, Srednii, and Varanger peninsulas, on Paikhoi (Amderma region) and Vaigach Island, and in the southern part of the Novaya Zemlya archipelago. These complexes were recovered by several boreholes in the Pechora plate and, according to geophysical data, are traceable in the Barents Sea shelf [2, 3].
Doklady Earth Sciences | 2006
O. V. Udoratina; A. A. Soboleva; N. A. Kuzenkov; N. V. Rodionov; S. L. Presnyakov
The Man’khambo and Il’yaiz plutons are situated in the northern Urals at the main divide of the Urals (basins of Shchugor, Ilych, and Severnaya Sos’va rivers). These plutons cut the Upper Riphean‐Vendian country rocks [1, 2] and, along with the latter ones, belong to Preuralides of the Central Ural Uplift. The Man’khambo and Il’yaiz plutons cover about 700 and 200 km 2 , respectively, and are the largest granitoid bodies of this tectonic unit. The plutons are localized in the core of the Man’khambo Anticlinorium, a part of the Lyapin‐Kutim Meganticlinorium of the Central Ural Uplift. The Man’khambo Pluton is a petrotype of the Sal’ner‐Man’khambo plutonic complex recognized in the regional scheme of correlation of igneous complexes and in legends of the state geological maps. The closely located plutons are similar in mineral and chemical compositions (Table 1) and consist of two intrusive phases. The first phase is composed of the major granite and leucogranite (main facies) and the subordinate quartz diorite and granodiorite (hybrid facies). Granitic rocks of the first phase occupy up to 90% of the exposed areas of the plutons. The second phase consists of leucogranite and alaskite. The dike suite is represented by aplite-like granites and aplites; pegmatites and rhyolites are less abundant. According to the petrochemical classification, the rocks of both phases belong to granite, leucogranite, subalkali granite and leucogranite, since the (Na 2 O + K 2 O) content
Doklady Earth Sciences | 2013
V. L. Andreichev; A. A. Soboleva; George E. Gehrels
In terms of neotectonics, the Timan Range and Kanin Peninsula represent a spacious mountainous structure 1150 km long and 80–160 km wide extend� ing in the northwesterly direction from Mount Poly� udov Kamen to Cape Kanin Nos in the Kanin Penin� sula. It consists of isolated en echelon arranged horst� like uplifts with Upper Precambrian rocks cropping out in their arch parts. In the southwest the Timan Range borders the Pechora Plate that surrounds the Karelian part of the East European Platform in the northeast. The boundary between the Pechora Plate and Mezen megablock of the East European Platform
Doklady Earth Sciences | 2012
A. A. Soboleva; A. F. Karchevskii; L. I. Efanova; N. B. Kuznetsov; Marty Grove; I. D. Sobolev; M. V. Maurin
181 The age of granitoid magmatism occurrences on the western slope of the Polar Urals ranges from ~730 to 480 Ma. The fact that most young rhyolites and granites (500–480 Ma) together with basaltoids and gabbroids of similar age are correlated to the rifting at the beginning of the Ural tectonic cycle is practically certain. The problem of correlating granitoids of the stage prior to the Ural cycle to certain geodynamic conditions is a subject of discussion at present.
Stratigraphy and Geological Correlation | 2014
V. L. Andreichev; A. A. Soboleva; George E. Gehrels
Timan comprises the southwest edge of the Pechora Plate. The plate basement is composed of variably metamorphosed sedimentary, mainly terrigenous, and igneous rocks of the Late Precambrian age that are generally overlain by Ordovician-Cenozoic platform cover. Poor exposition and discontinuous distribution of the Upper Precambrian outcrops of dominantly fossil-free sedimentary rocks cause considerable disagreements in stratigraphic correlation. This applies equally to North Timan, which represents an uplifted block of basement, in which sedimentary-metamorphic rocks form the Barminskaya Group (∼5000 m thick), previously dated as Early Riphean to Vendian. Earlier Rb-Sr and Sm-Nd isotope dating of schist and cross-cutting gabbro-dolerite and dolerite established the timing of greenschist facies metamorphism at 700 Ma. Thus, Late Riphean age of the Barminskaya Group has been suggested. Results of local U-Pb dating of detrital zircon from silty sandstones of the Malochernoretskaya Formation, which constitutes the middle part of the outcropping section of the Barminskaya Group, confirm this conclusion. Age data for 95 zircon grains cover the range of 1035–2883 Ma with age peaks at 1150, 1350, 1550, 1780, and 1885 Ma. The minimum age of zircons, considered as the lower age constraint on sediment deposition, provides grounds to date the Barminskaya Group as Late Riphean and indicates eroded rock complexes of the Fennoscandian Shield as the possible provenance areas.