The margin of the northeastern Black Sea is formed by the Crimea and Kerch peninsulas separating it from the Azov Sea to the north. The age and architecture of the sedimentary successions in this area are described from exploration reflection seismic profiling acquired in the area as well as the "one-off" regional DOBRE-2 CDP profile acquired in 2007. The sediments range in age from Mesozoic to Quaternary and can be divided into five "seismostratigraphic" complexes linked to the tectono-sedimentological evolution of the area. The present regional basin architecture consists of a series of basement structural highs separating a series of sedimentary depocentres and is mainly a consequence of the compressional tectonic regime affecting the area since the Eocene and which has focused shortening deformation and uplift along the axis of the Crimea-Caucasus inversion zone on the Kerch Peninsula and Kerch Shelf of the Black Sea. Two major sedimentary basins that mainly formed during this timethe Sorokin Trough in the Black Sea and the Indolo-Kuban Trough to the north of the Kerch Peninsula in the Azov Sea-formed as marginal troughs to the main inversion zone.
Magnetic, gravity, geothermal, seismic and tomographic data from the lithosphere were first jointly examined. A multidisciplinary interpretation has resulted in a new and consistent model for lithospheric density, magnetic, thermal and velocity heterogeneities. Faults of different orders for the crystalline crust have been mapped in details. Large deep fault zones were recognized. Among them is the most prominent Odessa-Sinop-Ordu (OSO) fault zone, which played a key role in the opening and development of the Black Sea Depression. A fundamental difference was revealed between the crustal and mantle structure and geophysical parameters of the Western Black Sea Basin (WBSB) and Eastern Black Sea Basin (EBSB). These dissimilarities are in the size of «non-granitic» crust, pattern and intensity of heat flow, topography of the lower boundary of the thermal lithosphere, mantle seismic velocity and structure of magnetic and residual gravity anomalies. Based on new information it was demonstrated that the WBSB and EBSB were diachronously formed on two large distinct continental blocks with independent post-rift development of the sub-basins. The rifting of the western sub-basin commenced earlier than that of the eastern one. The EBSB is characterized by younger thermal activity than the WBSB and consequently it was stabilized later. The Mid Black Sea High (MBSH) is not a single tectonic unit but is formed by two ridges of various crystalline crustal structure and age shifted relative to each other by the faults of the OSO zone.Key words: The Black Sea basins, magnetics, gravity, heat flow, fault tectonics, seismic tomography, lithosphere heterogeneity.Впервые проведен общий анализ магнитных, гравитационных, геотермических, сейсми-ческих и томографических данных о литосфере Черного моря. В результате комплексной интерпретации получена новая и согласованная модель плотностной, магнитной, термаль-ной и сейсмической неоднородностей литосферы. Построена подробная карта разломов консолидированной коры разных рангов. Выявлены зоны глубинных разломов. Среди них наиболее примечательна зона разлома Одесса-Синоп-Орду, игравшая ключевую роль в рас-крытии и развитии Черноморской впадины. Выявлены фундаментальніе различия в строе-нии и геофизических параметрах коры и литосферы Западно-и Восточно-Черноморской впадин. Эти различия заключаются в размере площади «безгранитной» коры, структуре и интенсивности теплового потока, топографии нижней границы термальной литосферы, осо-бенностях магнитного и остаточного гравитационного полей. На основе новой информации показано, что Западно-и Восточно-Черноморская впадины сформировались в разное время на двух различных крупных блоках континентальной коры с независимым пострифтовым развитием суббассейнов. Рифт в западном бассейне образовался раньше, чем в восточном. Восточно-Черноморская впадина отличается более молодой термической активностью, чем Западно-Черноморская, которая стабилизировалась позже. Центрально-Черноморское под-нятие не представляет собой единую тектоническую единицу, а сформиро...
A palaeomagnetic study and age determinations have been performed on Ediacaran basalts from the northwestern Ukraine. Whole-rock 40 Ar/ 39 Ar age determination revealed plateau ages at 590–560 Ma and 393 Ma, the latter probably reflecting a resetting of the radiometric system. Palaeomagnetic poles have been calculated from five basalt flows, two of which (A poles) are considered reliable with ages that range from 580 to 560 Ma. Tentative poles (B poles), calculated from most probably primary magnetizations, have ages estimated at 580–545 Ma. Secondary magnetizations, possibly of late Ediacaran or Devonian age, have also been isolated (C poles). Based on the new poles, Baltica drifted together with Laurentia from an equatorial position at c . 750 Ma to occupy high southern latitude positions at c . 580 Ma. Baltica during that time period was joined to Laurentia in a similar relative position to that at 750 Ma. The two shields then split up from each other and from c . 550 Ma Baltica drifted at moderately high latitudes and rotated some 180° during the final opening of the Iapetus ocean. This reconstruction suggests that during the Ediacaran glaciation Baltica occupied high-latitude positions, which contradicts the high-obliquity model to explain low-latitude Neoproterozoic glaciations.
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