Mikrofacje i wiek formacji wapienia pienińskiego (tyton-barrem) jednostki Grajcarka we wschodniej części pienińskiego pasa skałkowego
Abstract
MICROFACIES AND AGE OF THE PIENINY LIMESTONE FORMATION (TITHONIAN-BARREMIAN) OF THE GRAJCAREK UNIT, EASTERN PART OF THE PIENINY KLIPPEN BELT, CARPATHIANS
Summary
Microfacial analysis of the Pieniny Limestone Formation of the Grajcarek Unit (Pieniny Klippen Belt, Carpathians - see 2, 3) has been performed. A characteristic feature of this limestone in the Grajcarek Unit is a very small thickness (0.3-6 m) which is mainly primary due to condensed sedimentation, partly tectonic. Three stomiosphaerid zones have been distinguished. The moluccana Zone is the lowest one, indicating a Kimmeridgian age (see 5, 6, 9) of the basal part of the Pieniny Limestone Formation. It is followed by Early Tithonian zones malmica and pulla (see 6, 9, 11), however their mutual relation seems to be different from that reported by earlier authors: the malmica Zone always occurs below the pulla Zone in the profiles investigated by the author. A mass occurrence of stomiosphaerids with tests resembling those of Parastomiosphaera malmica (Borza) and Cadosina semiradiata Wanner is characteristic of the limestone beds immediately above the pulla Zone. These stomiosphaerids have been determined as Parastomiosphaera cf. malmica (probably new species). A characteristic Saccocoma horizon occurs between the stomiosphaerid and calpionellid zones in the sections investigated: the first chitinelloids appear here.
The middle part of the Pieniny Limestone Formation is characterized by the Calpionella Zone (Berrasian); neither Crassicollaria Zone (Late Tithonian) nor Early Cretaceous Calpionellopsis and Calpionellites zones have been recognized. A characteristic zone with Colomisphaera vogleri (Borza) appears above calpionellid zones. It indicates (5) an Upper Valanginian-Hauterivian age of the upper part of the limestone. Nannoconus microfacies with Colomisphaera tenuis (Nagy) and Stomiosphaera echinata Nowak are here characteristic. The topmost part of the limestone shows Hedbergella microfacies commonly regarded as Late Hauterivian (mainly Barremian) through Albian in age.
Taking into account the above data, the age of the Pieniny Limestone Formation in condensed facies of the Grajcarek Unit corresponds to an Upper Kimmeridgian through Upper Hauterivian (and ?Barremian) span. The lower boundary of the limestone seems to be diachronous.
Summary
Microfacial analysis of the Pieniny Limestone Formation of the Grajcarek Unit (Pieniny Klippen Belt, Carpathians - see 2, 3) has been performed. A characteristic feature of this limestone in the Grajcarek Unit is a very small thickness (0.3-6 m) which is mainly primary due to condensed sedimentation, partly tectonic. Three stomiosphaerid zones have been distinguished. The moluccana Zone is the lowest one, indicating a Kimmeridgian age (see 5, 6, 9) of the basal part of the Pieniny Limestone Formation. It is followed by Early Tithonian zones malmica and pulla (see 6, 9, 11), however their mutual relation seems to be different from that reported by earlier authors: the malmica Zone always occurs below the pulla Zone in the profiles investigated by the author. A mass occurrence of stomiosphaerids with tests resembling those of Parastomiosphaera malmica (Borza) and Cadosina semiradiata Wanner is characteristic of the limestone beds immediately above the pulla Zone. These stomiosphaerids have been determined as Parastomiosphaera cf. malmica (probably new species). A characteristic Saccocoma horizon occurs between the stomiosphaerid and calpionellid zones in the sections investigated: the first chitinelloids appear here.
The middle part of the Pieniny Limestone Formation is characterized by the Calpionella Zone (Berrasian); neither Crassicollaria Zone (Late Tithonian) nor Early Cretaceous Calpionellopsis and Calpionellites zones have been recognized. A characteristic zone with Colomisphaera vogleri (Borza) appears above calpionellid zones. It indicates (5) an Upper Valanginian-Hauterivian age of the upper part of the limestone. Nannoconus microfacies with Colomisphaera tenuis (Nagy) and Stomiosphaera echinata Nowak are here characteristic. The topmost part of the limestone shows Hedbergella microfacies commonly regarded as Late Hauterivian (mainly Barremian) through Albian in age.
Taking into account the above data, the age of the Pieniny Limestone Formation in condensed facies of the Grajcarek Unit corresponds to an Upper Kimmeridgian through Upper Hauterivian (and ?Barremian) span. The lower boundary of the limestone seems to be diachronous.