This paper presents a geological interpretation of the deep seismic profile Ivaylovgrad–Ardino, which was published in 1996. Four plates are distinguished according to their seismic features that build up the Eastern Rhodope Terrane. They have a total thickness of 22–24 km and layered structures with sub-oceanic character. The lower two plates (1, 2) are westward obducted on the Rila-Western Rhodope Terrane, forming one obduction complex. Plate 3 is probably also a part of the obduction complex. Plate 4 is thrust southward on all plates. A Kobilino Crypto-dome, comprising Plates 1 and 2 and covered discordantly by the third one, is found at the eastern part of the profile at 7–7.5 km depth. The two lower plates do not appear on the surface, but some ultrabasic to basic bodies are supposed to be parts of them, rising as tectonic slices. The Plate 3 is revealed on the surface at the eastern part of the seismic profile (east of Avren Fault), and is built up mainly by the Pre-Rhodopean Supergroup metamorphic rocks, respectively from the seismically indistinguishable Upper and Lower Allochthon. The Plate 4 appears mainly at the western end of the profile (between Mishevsko Village and Ardino Town), and is built up by the metamorphic rocks of the Rhodopean Supergroup from the Startsevo Lithotectonic Unit (or Middle Allochthon). Five fault and shear zone systems of different ages are distinguishable in all plates. Transparent areas in the plates are interpreted as magma chambers of the Paleogene volcanoes, others as Upper Cretaceous and Paleogene (?) plutons. Because these magmatic chambers are located in the sub-oceanic crust, both intermediate and acid Paleogene volcanics have isotopic characteristics similar to those of the metasomatized mantle.
Taxonomic descriptions of newly recorded inoceramid species from the Maastrichtian of the Western Fore-Balkan Mountains (Bulgaria) are presented. The following taxa have been determined: Cataceramus subcircularis (Meek, 1876); Cataceramus palliseri (Douglas, 1942); Cataceramus barabini (Morton, 1834); Cataceramus? glendivensis Walaszczyk, Cobban and Harries, 2001; Cataceramus? cf. bebahoensis (Sornay, 1973); Cataceramus aff. goldfussianus (d’Orbigny, 1847); Trochoceramus tenuiplicatus (Tzankov, 1981); Endocostea typica Whitfield, 1880; Endocostea jolkicevi Walaszczyk, Odin and Dhondt, 2002; Endocostea sp. aff. E. coxi (Reyment, 1955); and “Inoceramus” howletti Walaszczyk, Kennedy and Klinger, 2009. The present record allowed two lower Maastrichtian inoceramid zones, namely the Endocostea typica and Trochoceramus radiosus zones, to be indicated. The material allows for correlation with the Northwestern and Boreal areas of Europe and elsewhere.
Micropalaeontological and biostratigraphic studies of the Gurpi Formation were carried out at the Kuhe-Surgah section (Zagros Basin, Iran). In this research, 62 species of planktonic foraminifera, belonging to 23 genera, were recognized and used to describe the following zones: 1) Contusotruncana plummerae Interval Zone; 2) Radotruncana calcarata Total Range Zone; 3) Globotruncanella havanensis Partial Range Zone; 4) Globotruncana aegyptiaca Interval Zone; 5) Gansserina gansseri Interval Zone; 6) Contusotruncana contusa Interval Zone; 7) Abathomphalus mayaroensis Interval Zone; 8) Pseudoguembelina hariaensis Interval Zone; 9) Pseudotextularia elegans Interval Zone; 10) Parvularugoglobigerina eugubina Total Range Zone; 11) Parasubbotina pseudobulloides Interval Zone; and 12) Praemurica unicinata Interval Zone. Based on the ranges of planktonic foraminifera, the age of the Kuhe-Surgah section was estimated to be middle Campanian–late Danian.
Jurassic rocks in the Danube Region of northwestern Bulgaria and northeastern Serbia have been the subject of numerous earlier studies that have shown notable similarities between their sedimentary facies and depositional environments. In terms of regional palaeotectonic zonation, this area represents the westernmost parts of the Vidin Early–Middle Jurassic Complex Horst and the Mihaylovgrad Early–Middle Jurassic Graben in NW Bulgaria, as well as the easternmost part of the Lower Danubicum in NE Serbia, which collectively take part of the Jurassic Moesian Platform. For compiling an overall conception of the palaeoenvironments that existed during the Jurassic, nine palaeoenvironmental sketch maps, from the Aalenian to the late Tithonian, have been composed in this study, based on reinterpretation of the data borrowed from previous literature. It became evident that the Middle Jurassic sedimentary successions of the Danube Region record an evolution from an initially isolated lacustrine-palustrine depositional setting (Aalenian) to rapidly expanding shallow to moderately deeper-marine sandy-calcareous setting (late Bajocian–early Callovian). From the middle Callovian and onwards, during the Late Jurassic, the region became an area of laterally extensive pelagic and platform carbonate deposition. This interpretation is consistent with the available earlier data, but it links the facies and their respective settings from NW Bulgaria to NE Serbia, which has not been made to date and will be of benefit for future regional correlations.
No abstract is available for this article.
Bibliographies of references devoted to the geology of the Balkan Peninsula have periodically been annotated in Geologica Balcanica in earlier times, since many publications were either of a limited distribution or printed in native languages of the Balkan authors and, therefore, could not reach a wider international audience. At these times, the Editorial Board of Geologica Balcanica believed that “Bibliographia balcanica” would help readers of our journal stay informed about the news and achievements in the geology of the Balkan countries. Despite the rapid development of communication technologies over the last few decades, there are numerous works from Bulgaria that still remain poorly known both in our country and elsewhere. In this issue, we have compiled a reference list of Bulgarian doctoral dissertations in the field of geology defended in the last twenty years. As a rule, doctoral dissertations in Bulgaria remain unpublished and their authors often publish their results in research articles only partially. We are aware that the present bibliography may be incomplete and all works are written in Bulgarian; nevertheless, we believe that the references listed herein will be useful to our readers, since they would give them an idea about what contributions have been made during the last two decades.
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