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БИОСТРАТИГРАФИЯ ТИТОНСКОГО, БЕРРИАССКОГО
И ВАЛАНЖИНСКОГО ЯРУСОВ ПО КАЛПИОНЕЛЛАМ
В ГОРАХ СТАРОЙ ПЛАНИНЫ, БОЛГАРИЯ
И. Лакова, С. Петрова
Геологический институт, Болгарская академия наук, София,
lakova@geology.bas.bg, silviya_p@geology.bas.bg
HIGH-RESOLUTION CALPIONELLID BIOSTRATIGRAPHY
OF THE TITHONIAN, BERRIASIAN AND VALANGINIAN
IN THE BALKAN MTS, BULGARIA
I. Lakova, S. Petrova
Geological Institute, Bulgarian Academy of Sciences, Sofia, lakova@geology.bas.bg,
silviya_p@geology.bas.bg
Based on the vertical ranges of 53 chitinoidellid and calpionellid species in the
Tithonian to Valanginian time interval, a zonation of the pelagic carbonates (pink
nodular limestones, platty hard micritic limestones and clayey limestones alternated
with marls) from the Western Balkanides is proposed. It consists of widely accepted
calpionellid zones in the Mediterranean Realm, such as Chitinoidella, Praetintinnopsella,
Crassicollaria, Calpionella, Calpionellopsis, Calpionellites and Tintinnopsella.
Subzonal divisions are comparable to those in the Carpathians in Slovakia, Poland
and Romania. Direct correlations between ammonites and calpionellids suggest that
the base of the Upper Tithonian is to be traced at the FO of Chitinoidella boneti, that
of the Upper Berriasian – at the onset of the genus Calpionellopsis, and the base and
top of Lower Valanginian – at the FO and LO of the genus Calpionellites, respectively.
The Jurassic/Cretaceous boundary is placed at the base of Calpionella Zone
(Calpionella alpine Subzone) at the “explosion” of small sphaerical forms of Calpionella
alpine. The bloom of publications on detailed calpionellid zonations in 21 st
century covering a vast territory of the Mediterranean Realm from Cuba to Iran suggests
that a standard calpionellid zonation is to appear. Calpionellid zonal schemes
represent a background for calibrations with ammonites, calcareous nannofossils and
magnetic polarity chrons.
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