У статті наведено основні напрямки наукової та практичної роботи кафедри хірургії № 1, основні досягнення та перс-<br />пективи її подальшого розвитку.

The article presents the results of U-Pb isotope dating of detrital zircons from the Jurassic coarse rocks in the apex and the western slope of Mnt. Biyuk-Sinor (the southern wall of the Baidar basin, near the village of Orlinoe). These dates are compared with the detrital zircon dates obtained for sandy rocks from the Upper Jurassic coarse clastic strata composing the slopes of Mnt. Spilia near Balaklava Harbor and Mnt. Southern Demerdzhi near Alushta city, as well as the Middle Jurassic Bitak conglomerates near the village of Strogonovka (suburb of Simferopol city). The comparison shows a high degree of similarity of the averaged age characteristics of the main detrital zircon populations. Sandy rocks of Jurassic coarse clastic strata for zircon dating were sampled in four locations of the Mountaineous Crimea. Based on their dates and a summary set of ages of detrital zircon grains from sandstones of the Southern Coast of Crimea, spanning the stratigraphic interval from the Middle Jurassic to Neogene, we can provide a statistically reliable specification of the Carboniferous-Triassic time interval (360-200 Ma) of magmatic activity within the Black Sea region. This period was bounded in time by the Late Devonian and Early Jurassic relative magmatic lulls. None of the zircon grains of the Carboniferous-Triassic age has revealed Hf-isotopic characteristics indicating any significant contribution of crustal material older than the Meso proterozoic into the protolith of the parent zircon rocks. Within the Carboniferous-Triassic interval of magmatic activity, three stages are distinguished: (I) 360-315 Ma, (II) 315-270 Ma, and (III) 270-200 Ma. Magmatic stage I (360-315 Ma) is related to the closure of the Reik ocean, which completed after the subducted slab 'broke off' into the mantle and was accompanied by the ubiquitously manifested HT-LP metamorphism. Zircon grains of stage I are characterized by peak ages of about 325-340 Ma and the dominance of negative ε Hf. Magmatic stages II (315-270 Ma) and III (270-200 Ma) correlate with functioning of the Scythian-Pontian volcanic suprasubduction belt. In these magmatic stages, zircon ε Hf values scatter from weakly negative to substantially positive (referred to the depleted mantle), which is typical for volcanic arcs. Fuzzy separation of stages II and III and strong variability of the peak ages of zircons from the studied samples (which we associate with these stages) can be due both to changes in magmatic activity in different segments of the belt, and to changes in the erosion intensity of crystalline complexes of the belt during the subsequent stages evolution caused by tectonic rearrangements within the Paleo-Tethys ocean and its peri-oceanic structures.

The first isotope-geochemical and geochemical characteristics (the “TerraneChrone” method) of previously dated (U-Pb, LA-ICP-MS) detrital zircons from Ordovician sandstones (borehole Ordovician-2, Sol-Iletsk block) are presented. A comparative analysis of the characteristics of the studied zircons and the corresponding characteristics of the complexes composing the possible feeding provinces is carried out.

The U–Pb dating and Hf isotope systematics of detrital zircons from a sandstone interbed in the section of the upper conglomerate sequence of the Mt. South Demerdzhi were carried out. The dominant populations of detrital zircons in the studied sample characterize episodes of magmatic activity within the source of the Upper Jurassic conglomerates. Magmatism was manifested in the Vendian-Cambrian, Carbon-Triassic and Late Jurassic. The åHf values of detrital zircons of these ages indicate the insignificant role of the ancient (Archean–Early Proterozoic) continental crust in the protolith of magmatic chambers. The similarity of the detrital zircons age distribution from the Middle Jurassic and Upper Jurassic conglomerate strata suggests that they are molasses of the Cimmerian orogen. The absence of products of Middle Jurassic magmatism in molasses of the Cimmerian orogen, which we fixed, limits position of the Cimmerian orogen in the southern part of the Scythian plate. It is shown that the primary source of the Precambrian detrital zircons were mobilized within the Cimmerian orogen the crustal fragments of the Peri-Gondwanan origin, rather than the basement complexes of the East European Platform, similar to the complexes of the Ukrainian shield. The reconstruction of the main stages of the accumulation of the coarse-grained strata of the Mountaineous Crimea in the context of the tectonic evolution of the southern margin of Laurasia during the Mesozoic is presented.

Изучен характер распределения возрастов детритного циркона из верхнерифейских и раннекаменноугольных песчаников северо-западной части Земли Норденшельда (о. Западный Шпицберген). Полученные результаты дополняют данные, известные ранее для пород докембрийских и палеозойских толщ запада Шпицбергена. Совместное рассмотрение этих данных показывает, что временной интервал средний рифей - ранний карбон включительно подразделяется (как минимум) на 5 этапов, во время которых питающие провинции, поставлявшие детрит в осадочные бассейны, реликты которых представлены в современной структуре Западного Шпицбергена, существенно различались. Самый древний из выявленных эпизодов изменения источников осадочного материала (рубеж среднего и позднего рифея) соответствует времени консолидации древнего фундамента архипелага Шпицберген.