The Middle Oxfordian Platysphinctes event-horizon – an integrated tool in the correlations around the boundary of the Plicatilis and Transversarium zones in Europe

• Autorzy: Glowniak E. , Wierzbowski H.
• Konferencja: International Congress on the Jurassic System (7 ; 06-18.09.2006 ; Kraków, Poland)
• Języki publikacji: EN

Abstrakty

EN

Palaeobiogeographic differentiation of the Late Jurassic faunas of the northern hemisphere was connected with temporal excursions and mixing of the Boreal-Subboreal and Mediterranean ammonites in the area of the Submediterranean epicratonic seas of the northern Tethyan shelf. These excursions are well recognized from the Late Oxfordian onwards (e.g. Atrops et al. 1993) but are less well-known in the Middle Oxfordian. However, the lower Mid-Oxfordian Platysphinctes event-horizon first recognized in central Poland (GĐowniak 2000), has been recently evidenced also in southern Poland and NW Germany. According to the new study (GĐowniak 2006b, in press) it appears in central Europe within the Arkelli Horizon of the Arkelli Subzone (Mid-Oxfordian Plicatilis Zone in the usage of the Submediterranean zonal scheme based on perisphinctid lineage, GĐowniak 2002, 2006a) and was a proxy for a biogeographical phenomenon referred to as the “Mediterranean Spread”. At that time, geographical barriers did not hinder communication between the Submediterranean and Tethys basins, which may point to the occurrence of the “Mediterranean Spread” in conditions of a sea-level rise. In accordance with the previous opinion remain geochemical isotope data based on stratigraphically well-dated belemnite rostra derived from the Mid-Oxfordian sections of central Poland (Wierzbowski 2002). A gradual positive shift in ä13C values, which starts at the Lower/Middle Oxfordian boundary, reaches its maximum in the Platysphinctes event-horizon. According to Wierzbowski (2002) the early Middle Oxfordian carbon isotope excursion may have been linked to transgression, which occurred during a longer period of the crisis in oceanic carbonate sedimentation. The early Middle Oxfordian positive carbon isotope shift was subsequently recognized in the sections of Scotland (Wierzbowski 2004, Pearce et al. 2005). The geochemical events from Poland and Scotland are simultaneous and should be correlated with the Platysphinctes event-horizon (cf. Wierzbowski 2002, 2004). As a consequence, the latter becomes a precise marker for the stratigraphic correlations of the Mid-Oxfordian zonal schemes in the upper Plicatilis Zone between the Submediterranean and Boreal-Subboreal Europe.

Słowa kluczowe

EN

Upper Jurassic; Middle Oxfordian; Central & NW Europe; ammonites; carbon isotopes; correlations

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Volumina Jurassica
• Rocznik: 2006
• Tom: Vol. 4, no. 1
• Strony: 162--163
• Opis fizyczny: Bibliogr. 8 poz.

Twórcy

autor

Glowniak E.

autor

Wierzbowski H.

• Institute of Geology, University of Warsaw, Al. ˘Şwirki i Wigury 93, PL-02089 Warszawa, Poland,

Bibliografia

• Atrops F., Gygi R. A., Matyja B. A. and Wierzbowski A. 1993. The Amoeboceras faunas in the Middle Oxfordian – lowermost Kimmeridgian, Submediterranean succession, and their correlation value. Acta Geologica Polonica, 43: 213-227.
• Głowniak E. 2000. The Platysphinctes immigration event in the Middle Oxfordian of the Polish Jura Chain (Central Poland). Acta Geologica Polonica, 50: 143-160.
• Głowniak E. 2002. The ammonites of the family Perisphinctidae from the Plicatilis Zone (lower Middle Oxfordian) of the Polish Jura Chain (Central Poland); their taxonomy, phylogeny and biostratigraphy. Acta Geologica Polonica, 52: 307-364.
• Głowniak E. 2006a. The correlation of the zonal schemes at the Middle-Upper Oxfordian boundary (Jurassic) in the Submediterranean Province: Poland and Switzerland. Acta Geologica Polonica, 56: 33-50.
• Głowniak E. 2006b. The Platysphinctes immigration event: biostratigraphic and paleobiogeographic implications for the Middle Oxfordian (Late Jurassic) seas of central Europe (NW Germany and Poland). Neues Jahrbuch für Paläontologie Abhandlungen. (in press)
• Pearce C. R., Hesselbo S. P. and Coe A. L. 2005. The mid-Oxfordian (Late Jurassic) positive carbon-isotope excursion recognised from fossil wood in the British Isles. Palaeogeography, Palaeoclimatology, Palaeoecology, 221: 343-357.
• Wierzbowski H. 2002. Detailed oxygen and isotope stratigraphy of the Oxfordian in Central Poland. Geologische Rundschau, 91: 304-314.
• Wierzbowski H. 2004. Carbon and oxygen isotope composition of Oxfordian-Early Kimmeridgian belemnite rostra: palaeoenvironmental implications for Late Jurassic seas. Palaeogeography, Palaeoclimatology, Palaeoecology, 203: 153-168.