The Bathonian and Callovian sediments of North Bulgaria yielded rich and commoly wellpreserved dinocyst assemblages. The assemblages studied are derived from 70 boreholes and 2 outcrops. In the present paper the taxonomy of the Bathonian and Callovian dinocysts established is considered. According to the archeopyle type they are divided into 4 groups: dinocysts with apical archeopyle, dinocysts with intercalary archeopyle, dinocysts with precingular archeopyle and dinocysts with combination archeopyle. 86 species belonging to 42 genera, a lot of them being of considerable biostratigraphic importance, are described. The geographic distribution and stratigrapic range in Bulgaria of these species are presented. The genera identified are: Adnatosphaeridium, Atopodinium. Belodinium, Chlamydophorella, Cleistosphaeridium, Compositosphaeridium, Dingodinium, Ellipsoidictyum, Escharisphaeridia, Kylindrocysta, Lagenadinium, Lithodinia, Parvulodinium, Rigaudella, Sentusidinium, Stephanelytron, Valensiella, Carpathodinium, Glomodinium, Kalyptea, Pareodinia, Tabulodinium gen. n., Aldorfia, Chytroeisphaeridia, Diacanthum, Gonylodinium, Gonyaulacysta, Heslertonia, Rhynchodiniopsis, Scriniodinium, Tubotuberella, Ctenidodinium, Dodekovia, Eodinia, Korystocysta, Mendicodinium, Mosaicodinium gen. n., Nannoceratopsis, Polygonifera. Sirmiodiniopsis, Sirmiodinium, Wanaea. Predominating in the composition of the dinocyst assemblages are the species of the genera Ctenidodinium Lithodinia, Gonyaulacysta and Pareodinia. The following new species are described: Tabulodinium senarium sp. n. and Polygonifera? aspera sp. n., a new combination – Mosaicodinium mosaicum comb. n., and Lithodinia. sp. A and Lithodinia sp. B. In order some characteristic morphological feature in the species of the genus Tubotuberella to be determined, a new term – inclination has been introduction.
No abstract is available for this publication.
D. Kozhoukharov, M. Konzalova. First finds of microphytofossils in the marbles of Dobrostan Formation. Nothem and Southern Pirin. Preliminary results of the studies on 12 samples from Dobrostan Formation along three profiles in Northern and Southern Pirin Mountain, as well as on one sample from the stratotype of the Formation in the Central Rhodope Mountains, revealed different amounts of organic matter. The latter consists of organic coats, plant detritus, graphite crystals and kerogene matter, and contains also specimens of microphytofossils in differing state of preservation. The following taxa have been determined: Protosphaeridium sp., Protosplweridium den sum Tim., Kildinella sp., Kildinella cf. sinica Tim., Kildinella cf. hyperboreica Tim., and Trachysphearidium (?) sp. These microphytofossils are characteristic for the Upper Proterozoic (Riphean). The presence of the genus Kildinella – a guide fossil for the Riphean of Eurasia, confirms the Riphean age of Dobrostan Formation in Pirin Mountain, i.e. the same age already establi shed for this Formation in its type region.
Stoilovo Formation comprises phyllitoid slates, phyllites, metapsammites, marbles, basic and acid metavolcanics. Thirty samples throughout the whole area made of Veleka Group were studied. Only three samples yielded results. Only one sample contains palynomorphs suitable for age determination.
Cavate spores were identified and referred to the formgenus Densoisporires. The species Densoisporites neiburgii was also found. It is characteristic of many Early Triassic successions in different parts of the world (Europe, Asia, Australia). At least three different types of acritarchs were establi shed. The forms of g. Veryhachium may be well compared to Veryhachium valensii.
It is assumed that the combined occurrence of Densoisporites nejburaii or morphologcally related cavate forms of Veryhachium in low diversity assemblages is one of the most striking features of marine Early Triassic assembl ages.
No abstract is available for this article.
T. Dobrev, P. Stavrev, D. Yossiffov, R. Radichev, K. Vikov. Sputial distribution and morphological features of magmatic cryptobodies in Bulgaria according to geophysical data. Reported are results of studies related to the presence, positions, morphologies and sratial distribution of buried magmatic bodies in Bulgaria according to geophysical data gathered in scale 1:200 000. The methodology of interpretation is based on computer modelling of bodies and their anomalies. The analysis and descriptions are covering cryptobodies within upper 10–15 km of the earth crust southwards of Moesian platform. The highest density of magmatic bodies is related to the Srednogorie structural zone and mainly to its eastern subzone. All bodies are located within an interval of depths increasing from 7 km in the west towards 15-16 km in east direction. The number and relative percentage of basic bodies increase eastwards too. Predominating are layer-like bodies of fracture type. The results obtained are to be used for better understanding of the magmatism in the upper part of the earth crust and for an evaluation of low scale estimates of the ore-bearing potential of structural units in Bulgaria.
Some velocity characteristics of the crust and upper mantle in the central part of the Balkan region are studied on the basis of about 1000 local and teleseismic earthquakes, registered on the 32 seismic stations. An approach for estimation of the large anisotropic structures effects is used together with the general consideration about the connection between the time residuals and velocity inhomogeneities. The main features of the inhomogeneities in the crust and upper mantle are drscussed in relation with some gravity, heat flow and seismotectonic data. The distribution of the crustal inhomogeneities in general corresponds to the configuration of the morphotectonic structures in Bulgaria. The subcrustal inhomogeneities are discordant with the surface structures, but their orientation is in coincidence with the Trans-Balkan seismolineament system. This fact indicates that the crustal seismicity in the region is probably controlled by the upper mantle structures. The high-velocity structures in the deep upper mantle beneath the Rhodope massif probably represent a paleosubduction at a depth more than 300 km.
No abstract is available for this publication.
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