Structure of the Earth's crust and upper mantle of the West- and East-Black Sea Basins revealed from geophysical data and its tectonic implications

Abstract

A back-arc Black Sea Basin consists of two deep sub-basins – the West-Black Sea (WBS) and the East-Black Sea (EBS) – filled with thick sediments (up to 12–14 km), which are separated by the mid–Black Sea Ridge (MBSR) – a NW trending basement uplift structure. For a better understanding of the lithosphere structure of these two sub-basins, the authors made a comprehensive analysis of the available geological and geophysical data, including carrying out a three-dimensional (3D) gravity back-stripping analysis, a reinterpretation of a number of seismic refraction profiles as well as the re-evaluation of seismological data and local seismic tomography. Inferred differences in the basin architecture and lithosphere structure of the WBS and EBS can be explained by different affinities of the underlying crustal domains and by the peculiarities of their (Cretaceous and younger) rift and post-rift history. Rifting that led to oceanic crust formation in the WBS occurred within the continental crust of the Moesian Platform along Mesozoic sutures with adjoining accreted terranes. The EBS, most probably, formed within the Transcaucasus continental domain due to strike–slip movements along the MBSR. Underthrusting of the EBS oceanic lithosphere beneath the continental domain of the Scythian Platform led to the formation offshore of the Crimean orogen of accretional wedge of Sorokin Trough.

Heterogeneous structure of the lithosphere in the Black Sea from a multidisciplinary analysis of geophysical fields

“…This inference does not contradict the model involving rifting of thermally and mechanically different lithosphere beneath the Black Sea subbasins [Spadini et al, 1996]. Seismic tomography revealed different structure velocity of the lithosphere up to 150 km depth in the EBSB and WBSB [Bugaenko et al, 2008;Yegorova, Gobarenko, 2010;Yegorova et al, 2013].…”

“…They were made during 55 years by various industrial and academic organizations from the Former Soviet Union including the Institute of Geophysics of the National Academy of Sciences of Ukraine [Starostenko et al, 2004a]. The map is much more detailed and informative than those of published earlier [Belousov et al, 1988;Spadini et al, 1996;Starostenko et al, 2004a;Sandwell, Smith, 2009;Yegorova, Gobarenko, 2010].…”

Structural, tectonic and fluid-dynamic aspects of deep degassing of the black sea megatrench

“…В этой связи, большого внимания заслуживают различные признаки зонального и локального разуплотнения в пределах фундамента мегавпадины Черного моря. В частности, особый интерес пред-ставляет обнаружение волновода в фундаменте севе-ро-западного шельфа Черного моря по результатам переинтерпретации материалов ГСЗ профилей 26 и 25 (Baranova, Egorova, & Omel'chenko, 2008;Yegorova & Gobarenko, 2010: Yegorova, Baranova, & Omelchenko, 2010.…”

Geodynamic features of joint zone of the Eurasian plate and the Alpine-Himalayan belt within the limits of Ukraine and adjacent areas

“…Òàêaeå ñîòðóäíèêàìè ÈÃÔ [Áàðàíîâà è äð., 2008;Ãîáàðåíêî, Åãîðîâà, 2008;Yegorova, Gobarenko, 2010;Ãîáàðåíêî, ßíîâñêàÿ, 2011;Åãîðî-âà è äð., 2012;Êîçëåíêî è äð., 2013] âûïîëíåíû ðàáîòû ìåòîäîì ëîêàëüíîé ñåéñìîòîìîãðàôèè â ïðåäåëàõ ×åðíîìîðñêîé âïàäèíû è ïåðåèí-òåðïðåòàöèÿ ïåðåñåêàþùèõ åå íåêîòîðûõ ñòà-ðûõ ïðîôèëåé ÃÑÇ ñ èñïîëüçîâàíèåì íîâûõ ìå-òîäîâ âîëíîâîãî êîìïüþòåðíîãî ìîäåëèðîâàíèÿ. Ýòî ñòàëî îñíîâîé äëÿ ïîñòðîåíèÿ íîâûõ ïëîò-íîñòíîé, ãåîòåðìè÷åñêîé è ãåîìàãíèòíîé ìîäå-ëåé çåìíîé êîðû âïàäèíû è óòî÷íåíèÿ åå êîðî-âûõ ãðàíèö [Ñòàðîñòåíêî è äð., 2010; Êóòàñ, 2010; Åãîðîâà è äð., 2012; Îðëþê è äð., 2013].…”

“…Ñîîòíîøåíèå ìîùíîñòè, ñêîðîñòíîé è ïëîò-íîñòíîé õàðàêòåðèñòèê êîðû èññëåäóåìîãî ðå-ãèîíà ïîêàçûâàþò, ÷òî êîðà ÀÃÏ òîíüøå è ëåã-÷å êîðû ÅÀÏ Áàðàíîâà è äð., 2008;Ñòàðîñòåíêî è äð., 2010;Yegorova, Gobarenko, 2010;Ãîáàðåíêî, ßíîâñêàÿ, 2011;Åãîðîâà è äð., 2012;Òðèïîëüñêèé è äð., 2012;Êîçëåíêî è äð., 2013]. Ïî îðèåíòèðîâî÷íîé ïðè-êèäêå ñðåäíÿÿ ñêîðîñòü ïðîäîëüíûõ âîëí â êî-ðå ÀÃÏ íà 0,40,6 êì/ñ íèaeå, ÷åì â êîðå ÅÀÏ, à ñðåäíÿÿ ïëîòíîñòü ñîîòâåòñòâåííî ìåíüøå íà 0,080,12 ã/ñì 3 (ïîñðåäñòâîì îáîáùåíèÿ ïðè-âîäèìûõ ðàçëè÷íûìè àâòîðàìè ñîîòíîøåíèé σ = f (V P ) ìîaeíî ïðèíÿòü ïðèáëèaeåííûå ñîîò-íîøåíèÿ Δσ ≈ 0,2 ΔV P äëÿ êîðû è Δσ ≈ 0,3 ΔV P äëÿ âåðõíåé ìàíòèè).…”