Conodont stratigraphy, facies related distribution patterns and stable isotopes (carbon and oxygen) of the uppermost Silurian to Lower Devonian Seewarte section (Carnic Alps, Carinthia, Austria) / Verf.: Thomas James Suttner

• VerfasserIn: Suttner, Thomas J.
• Place / Publishing House: 2006
• Year of Publication: 2006
• Language: English
• Classification: 38.16 - Stratigraphie; 38.22 - Paläozoologie; 38.23 - Palökologie; 38.28 - Sedimentgesteine; 38.00 - Geowissenschaften: Allgemeines
• Physical Description: 169 Bl.; zahlr. Ill., graph. Darst., Kt.
• Notes: Abweichender Titel laut Übersetzung der Verfasserin/des Verfassers

ger: In the course of the PhD, the Pridolian to Pragian succession of Mount Seewarte (Wolayer Area, Carnic Alps) was investigated. The sequence includes the Megaerella Formation (distal shelf sediments; only uppermost 5m exposed), the Rauchkofel Formation (neritic facies; 120m) and the Hohe Warte Formation (platform sediments; at least 200m). The present investigations provide new conodont data enabling more precise time-allocation of these formations then suggested by VAI (1973) and other authors.<br />Abundant conodonts were obtained from the Megaerella Formation indicating a late Pridolian age (e.g.: Belodella anomalis, Oulodus elegans detorta, Oulodus elegans elegans, Ozarkodina excavata excavata, Ozarkodina aff. O. remscheidensis eosteinhornensis, Ozarkodina remscheidensis remscheidensis). The lower part of the Rauchkofel Formation produced a diverse fauna referred to the delta Zone (e.g.:<br />Ancyrodelloides kutscheri, Ancyrodelloides limbacarinatus, Ancyrodelloides transitans, Flajsella schulzei, Flajsella stygia, Lanea omoalpha, Lanea eoeleanorae and Lanea telleri). Above the last occurrence of the typical delta fauna, M2 elements of Pedavis sp. were discovered within a narrow interval. It is succeeded by a remarkable megaclast horizon the matrix of which yields elements of Latericriodus steinachensis (assigned to both beta and eta morphotypes) indicating the base of the Pragian. Difficulties were experienced in applying the standard conodont zonation to the shallow marine and platform environments of the Pragian Hohe Warte Formation. Though the conodont assemblages lack Pa elements of Eognathodus, the record of Latericriodus steinachensis, Pelekysgnathus sp. and Caudicriodus aff. C. celtibericus supports the alternative zonation for the Pragian Stage suggested by SLAVÍK (2004b). Additional sparsely distributed spathognathodontids such as Ozarkodina remscheidensis repetitor, Pandorinellina cf. Pand.<br />ebzeryi, Pandorinellina miae, Pandorinellina optima optima and simple cones (Coelocerodontus cf. C. reduncus, Decoriconus fragilis, Neopanderodus aequabilis, Neopanderodus leptostriatus) were identified.<br />The color alteration index of the obtained conodont elements indicates a CAI of 3.<br />Additional analyses of stable isotopes, mainly used as tool for stratigraphical correlation, show a positive trend across the suggested Silurian-Devonian boundary. A strong excursion known from other sections of the Carnic Alps and the Prague Syncline suggests that the equivalent interval assigned to the woschmidti Zone is missing or yet not identified. A positive shift of suddenly increased values at the base of the megaclast horizon correlate with the first occurrence of Latericriodus cf. L. steinachensis beta morph, indicating the base of the Pragian Stage. Subsequent facial analyses provide data supporting patterns of accumulative distribution of isolated conodont elements in shallow water environments.