Palynology, T/J boundary microfacies, clay mineralogy, C and O isotopes and other palaeoclimatic indicators from the Tatra Mts.

• Autorzy: Götz A. , Ruckwied K. , Biroń A. , Lintnerová O. , Michalík J.
• Konferencja: International Congress on the Jurassic System (7 ; 06-18.09.2006 ; Kraków, Poland)
• Języki publikacji: EN

Abstrakty

EN

The Furkaska and Kardolina sections expose a complete succesion of the uppermost Fatra Formation and the lowermost Kopienec Formation. The Upper Triassic Fatra Fm. is characterized by bioclastic limestones and fine-grained clastics overlain by dark claystones with intercalated sandstones (Cardinia Sandstein) of the Kopienec Formation. Due to lack of age-diagnostic index fossils, the precise position of the Triassic/Jurassic boundary is not yet known. Based on negative excursion of the δ ¹ ³C carbonate isotopic curve and microfacies analyses the boundary interval was placed near the transition of two formations. Palynological analysis was focused on palaeoenvironmental and stratigraphical aspects. Generally, the continental fraction shows a high amount of phytoclasts. The few marine organic depositional environment indicate a very shallow marine depositional environment. The palynomorph assemblage of the Fatra Fm. is characterized by numerous Ricciisporites tuberculatus. The marine fraction of this part of the sections is dominated by dinoflagellate cyst Rhaetogonyaulax rhaetica. Microflora of the Upper Fatra Formation is very similar to the Ricciisporites tuberculatus Zone of the Polish zonation and Ricciisporites-Polzdiisporites Zone of the SE Nord Sea Basin, both indicating a Middle to Late Rhaetian age. The palynomorph assemblage of the Kopienec Formation is characterized by a significant increase of trilete laevigate spores, mainly Deltoidospora spp. and Concavisporites spp. The dinoflagellate cyst Dapcodinium priscum replaces Rhaetogonyaulax rhaetica in the marine fraction. These changes may be caused by a regression at the Triassic/Jurassic boundary. Quantitative clay minerals analyses documented palaeoclimatic, palaeogeographic and postsedimentary changes in the boundary event and integrated palynological results. Mixed layer illite/smectite (I/S) smectite interlayers take about 80% of the clay fraction and their low content of smectite (10-20%) indicate relatively high diagenetic overprint of the Fatra and Kopienec formations claystones corresponding with burial temperature of 150oC. Varied contents of detrital illite, chlorite and kaolinite were used to demonstrate climatic changes in the hinterland and indicated depositional condition in this semi-restricted basin. Kaolinite and low illite/kaolinite ration indicate more humid climate during earliest Jurassic in comparison with the Rhaetian condition of illite/chlorite dominance. Peak occurrence of kaolinite at the base of the Kopienec Formation recorded different source and strong input of material from weathered and eroded land into proximal part of deltaic plain in comparison with the Fatra Formation.

Słowa kluczowe

EN

T/J boundary; Western Carpathians; sedimentary facies; clay mineralogy; stable isotope signatures; palynology

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Volumina Jurassica
• Rocznik: 2006
• Tom: Vol. 4, no. 1
• Strony: 282--283

Twórcy

autor

Götz A.

autor

Ruckwied K.

autor

Biroń A.

autor

Lintnerová O.

autor

Michalík J.

• Institute of Geosciences, Martin-Luther-University Halle-Wittenberg, D-06099 Halle (Saale), Germany,