THE MEDITERRANEAN LOWER CRETACEOUS

In the zone of the villages Zamfirovo — DraSan the Hauterivian is connected
predominantly with the Brestnica or with the Salas Formation.
A number of biostratigraphic proofs of the presence of the Hauterivian have
been found in the boreholes as well.
The Hauterivian is heterofacial, connected with the Brestnica and Salas Formations
which are involved in complex interrelations. The thickness of the Hauterivian
in the Western Fore-Balkan is 95-700 m.
There exists biostratigraphic evidence about the presence of the Barremian
both in the natural outcrops and in a number of boreholes.
The following species are found among the marls of the Mramoren Formation
from the natural outcrops near the village of Cerkaski, Mihajlovgrad District (M aполов,
1962): Cymatoceras neocomiense (d'O г b.), Phyllopachiceras infunclibuhim
(d'O r b.), Barremites cf. difficilis (d'O r b.), B. subdifficilis (К а г.), Silesitcs
vulpes (С о q.), Hibolites cf. subfusiformis (Ras p.).
Manolov (Манолов, 1962) reports Barremites charrieriamis (d'O r b.)
from the uppermost part of the Mramoren Formation near Stojanovo village.
The presence of Barremian sediments on Pâstrinata hill has been proved by
Popov and Hristanova (Попов, Христанова, 1961) with the
following ammonite association: Crioceratites emerici Lev., Anahamulina subcylindrica
(d'O г b.), Barremites ponticus (К. а г.), В. charrierianus (d'O r b.) and
Pseudosaynella strettostoma (U h I.).
The presence of the Barremian has also been proved with the macrofauna in
a number of structural boreholes.
P. Jovceva has found characteristic foraminifera associations determining
the Barremian at several levels in R-l Goljamo Pestene (oral communication).
By means of a rich ammonite association found in the outcrops of the Mramoren
Formation, immediately below the Urgonian limestones in the Ciren area (Д и м итрова,
1967), the Late Barremian of the upper part of the Mramoren Formation
in this region has been proved: Barremites vocontius (Say n), B. subdifficilis
(К а г.), В. nabdalsa (С о q.), В. sequenze (С о q.), В. tenuicinctus (S а г., S с h.),
Pseudosaynella strettostoma (U h 1.), and Pulchellia sauvageani (Her m.).
Kovatcheva (oral communication) has defined the following characteristic
Upper Barremian foraminifera association in R-l Drasan, in the interval
1669-2284 m: Lenticulina nodosa (Reus s), Arenobulimina meltae К о v., Conorotalites
inter cedens (Bet t.), Gaudryina borimensis К о v., Marssonella kummi
Z e d 1., Lamarckina lamplughi (S h e г 1), Quinqueloculina pseudominima Bart.,
К о v., Epistomina hechti Bart., В et t., В о 11 i, Choffatella decipiens Schl.,
Flabellammina urgonensis В a г t., Ko v., Epistomina caracolla (Roe m.) and
Trocholina infragranulata N о t h.
The Barremian in the Western Fore-Balkan is markedly heterofacial. It is
connected with the Brestnica, Salas and Mramoren Formations. Thickness:
100-1000 m.
The development of the Aptian in the Western Fore-Balkan is well known from
the data of the outcrops. Borehole data provided considerable new information about
the comprehensive characteristics of this stage.
There exist numerous biostratigraphic proofs about the presence and completeness
of the Aptian and of its three substages: Bedoulian, Gargasian and Clansayesian
(B. Цанков, 1960; Димитрова et al., 1961; Манолов, 1962;
Николов, Хрисчев, 1965b; Николов, 1969b; 1970).
The Lower Aptian (Bedoulian) is proved by the following ammonites found
to the north of Liljaôe village: Deshayesites weissi (Ne urn, Uhl.), D. deshayesi
(Ley in.), D. bodei (К о e n), Deshayesites sp. and Cheloniceras sp.
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