THE MEDITERRANEAN LOWER CRETACEOUS

In the Crimea the Valanginian deposits are more widespread than the Berriasian
sediments and in some places they overlie transgressively older rocks. In the
Theodosia region the stage comprises the middle part of the Lower Cretaceous
outcrops. It is represented by calcareous claystones with marl intercalations. This
type of sediments is traced in the west until the valleys of the rivers Tonas and Indol.
Transgressive position of the Valanginian glauconitic clayey sandstones over
the Tithonian flysch is observed in the valley of Burulca river. In the southeast,
in the valley of Belbek river, the Valanginian transgressively overlies the Tavric
series. Conglomerates are developed at its base, followed above by clayey-calcareous
sandstones with different faunas, including ammonites.
In Northwestern Caucasus the Valanginian comprises clayey-marl sediments
and limestones with different faunas. In Central Caucasus the stage is built of micrograined
limestones, often recrystallized and poor in fossils. These carbonate sediments
gradually decrease in thickness and in Dagestan they are 25-30 m thick.
In the southern part of Dagestan the limestones become sandy and intercalations
of marls appear. Near Hanagcai river they are replaced by sandy coastal facies,
and in some places they are completely wedged out.
Clayey-carbonate and carbonate sediments of insignificant thicknesses occur
in the Georgian zone. They contain characteristic ammonites. A formation of cryptocrystalline
limestones and dolomitized limestones with scanty gastropod fauna
is developed in the upper part of the Stage.
In Caucasus Minor the Valanginian is developed in several zones, the sections
in the Kafan zone being.the most clearly seen, where terrigenous-carbonate sediments
with typical Mediterranean fauna are developed.
In Bulgaria the Valanginian is represented by neritic carbonates, extensively
developed in the Moesian Platform, by flyschoid sediments — in the greater part
of the Fore-Balkan, the Kula region and the Kraiste, and by clayey-calcareous deposits
in the Western Fore-Balkan, the Lorn Depression and Western Balkan Mountains
(the Gubes syncline).
In the Dinarides and Hellenides the Valanginian is connected with carbonate
and flysch sediments.
The Valanginian sediments demonstrate considerable variety in the zone of
Sumadia and Eastern Serbia, where neritic to deep-sea facies are observed.
In the southeast, towards Turkey and the Middle East, the Valanginian sediments
are developed in neritic carbonate or terrigenous-carbonate facies with scanty
fauna.
Only in some regions of Turkey, especially in Anatolia, the Valanginian is
connected with deeper-sea clayey-carbonate sediments.
To the east of Iran, towards Afghanistan and Pakistan, many Himalayan species
appear among the Valanginian faunas.
3. HAUTERIVIAN
The Hauterivian sediments have considerable distribution and they are with very
varied facies.
In the Atlantic Ocean, in the Cape Verde Islands, the Hauterivian comprises
the upper part of the slightly metamorphosed deep-sea limestones, covered with
basalt lava which was poured at the end of the Hauterivian.
In the north, in the continental base of the Moroccan Meseta, the Hauterivian
is connected with part of the thick Lower Cretaceous flysch complex, whereas between
the Canary Islands and Cape Bojador it is connected with aleuritic argillites
containing siderite concretions. These sediments contain many remains of fishes,
echinoderms, gastropods and cephalopods, and they manifest deltaic facies.
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