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Palynostratigraphy of the Dobrindol Formation (Upper Turonian Santonian) in a part of Northeastern Bulgaria.
| Pavlishina, P. | |
| 1994 | |
| Bulgarian Academy of Sciences, Palaeontology, stratigraphy and lithology 30, pp. 51-58.Bulgarian Ac | |
| Palynostratigraphy of the Dobrindol Formation (Upper Turonian Santonian) in a part of Northeastern Bulgaria. |
Pavlishina, P., 1994. Palynostratigraphy of the Dobrindol Formation (Upper Turonian Santonian) in a part of Northeastern Bulgaria. Bulgarian Academy of Sciences, Palaeontology, stratigraphy and lithology 30, pp. 51-58. Introduction: Systematic palynological investigations are not carried out for Upper Cretaceous sediments in Northeastern Bulgaria. The present study is a first attempt for reporting Coniacian and Santonian palynomorphs, to evaluate the ranges of their species and to draw out the successions characterizing this time interval. Object of investigation are the deposites of the Dobrindol Formation. It is represented by phosphorite bed, glauconite sandstones, sandy to silty and nodular limestones with glauconite. These deposites can be traced through the borders of the plateaus in Northeastern Bulgaria, as well as in the northern margins of the Eastern Fore-Balkan. Their age has been considered as Late Turonian during the first stratigraphic investigations. The formation is established by Yolkichev (1988). According to macrofauna he defines its chronostratigraphical range as Upper Turonian-Lower Santonian, lower part. Following the same author, the Turonian--Coniacian boundary is traced at the base of the Dobrindol Formation (Fig. 1) and is marked at the appearance of Hoursquia aff. desmoulinsi (Grossorve), Micraster coranguinum KLein, Echinocorys ex. gr. scutata Leske, whereas in the investigated sections at Micraster coranguinum. The Coniacian foraminiferal associations are published by Dimitrova (ln ?Polkpiev, 1988, 1989). They are poor and are represented by the following species: Globtoruncana cf. renzi Gandolfi, G. coronata Bolli, G. tafrayensis Lehman. The biostratigraphical boundary between the Coniacian and Santonian is provisional in most sections and is marked by disappearance of these taxa and at the appearance of Micraster rogale Nowak and Pseudovalvulinaria thalmanni (Balakhmatova).