THE MEDITERRANEAN LOWER CRETACEOUS

and Salas Formations, and on the other —with the carbonate building of the Brestnica
Formation. • }д
The Berriasian in the Western Fore-Balkan is 90-450 m thick. The greater
thicknesses are related to the Brestnica Limestone Formation.
The Lower Cretaceous section in the zone of the villages Salas — Ciren is filled
upwards by the sediments of the Valanginian, with the exception of the area between
the villages Celjustnica — Prevala, where they are absent. In all remaining
sections of this zone the Valanginian is connected with the Salas Formation. It is
represented predominantly by micritic limestones, clayey limestones and intercalations
of marls.
In the zone of the villages Zamfirovo — Drasan — Reselec the Valanginian
is connected with the Brestnica and/ or the Salas Formations. The presence of the
Valanginian in the outcrops has been characterized well by N i к о 1 о v and К h r ischev
(Николов, Хрисчев, 1965b), Nikolov and Tzankov
(H и к о л о в, Цанков, 1971) and Mandov (Мандов, 1976).
In the locality of Pâstrinata the Valanginian is proved by: Thurmanniceras
sp., Busnardoites campylotoxus (U h 1.), Neocomites (N.) neocomiensis subtenius
S a y n, N. (Eristavites) platycostatus S a y n, Saynoceras verrucosum S a y n, etc.
The two ammonite zones of the Valanginian are proved in the eastern part of
the Western Fore-Balkan, in the zone of the transition between the pelagic clayeycalcareous
and flysch facies (Salas — Cerni Osâm Formation) (Николов,
Хрисчев, 1965a).
A characteristic Valanginian ammonite association is found in the transition
zone Salas — Brestnica Formation to the north of Glozene village, in the Vedrovete
locality (Николов, Хрисчев, 1965a): Kilianella ischnotera (Say n),
Kilianella sp., Sarasinella trezanensis (Say n), N. (N.) neocomiensis (d'O r b.),
N. (N.) neocomiensis premolicus S a y n, N. (N.) neocomiensis subquadratus, Thurmanniceras
sp., etc.
No Valanginian macrofauna has been found in the boreholes, with the exception
of Bochianites sp. in R-3 Ciren (924.50 m).
The differentiation of the Valanginian in the boreholes is made by comparison
with the outcrops and according to the microfauna. The thickness of the Valanginian
is from several tens of metres to 350 m.
The Hauterivian is well represented in the Western Fore-Balkan, where it is
connected with the Salas and Brestnica Formations. A number of authors have
contributed to the investigation of this stage, among whom Mandov (Мандов,
1976) deserves special credit for his very detailed study of the Hauterivian in the
Western Balkanides, comprising mainly natural outcrops.
The following species are found in outcrops of the Salas Formation in the Salas
syncline, especially near the villages Krapcene and Pali Lula: Phyllopachyceras
winckleri (U h 1.), Bochianites neocomiensis (d'O г b.), Himantoceras trinodosum
T h., H. acuticostatus T h., H. thieuloyi Mandov, Crioceratites andersoni
(S а г.), С. nolani (К i 1.), Crioceratites spp., Eleniceras spp., Olcostephanus sp.,
Lyticoceras cryptoceras (d'Orb.) and many others (Николов, Хрисчев,
1965b; Мандов, 1976).
In the Jablanica area the Hauterivian is proved by: Crioceratites duvali L é v.,
C. nolani (K i 1.), Crioceratites spp., Balearites balearis (N о 1.), Subosterella heliaca
(d'O г b.), Lyticoceras sp., etc.
In the zone of the Salas — Ciren villages the Hauterivian is connected with
the Salas Formation. Usually in this zone the lower boundary of the stage is marked
at about 100-120 m above the base of the Salas Formation, whereas the upper
boundary is at about 30-40 m below the upper part of this Formation.
50