(Miscellanea), Supplement 2 (Conodonta), 202 p., Lawrence,. Kansas (Univ. Kansas ... Wien 1991. KozuR, H. ... 8 Tab., Lawrence, Kansas 1970. SWEET, WC.
Conodonts ladinian Buchenstein (Southern Alps, ELIAS SAMANKASSOU*)
4 Text-Figures, 1 Table and 1 Plate
Italy Southern Alps Triassic Ladinian Buchenstein Formation Conodonts Systematic Biotacies
Contents
1. 2. 3.
4.
Zusammenfassung . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................................... . J.\bstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................. , ..... . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................ . Systematic Paleontology of the Conodont Fauna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........... . Quantitative Analysis and Possible Implications ........................................................................ . 3.1. Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 3.2. Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................................. . Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................ . Plate 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................................................................... . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................... .
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Conodonten aus den ladinischen Buchensteiner Schichten (Siidalpen, ltalien) Zusammenfassung Die Ladinischen Buchensteiner Schichten (Livinallongo Formation) wurden in der Umgebung van Vigo di Fassa, Dolomiten, Sudalpen (ltalien) untersucht. Die gut erhaltene Conodontenfauna besteht aus Vertretern der Familie Ellisonidae MOLLER, 1956 mil Ellisonia triassica MOLLER, 1956? und Gladigondolella tethydis (HUCKRIEDE, 1958), der Familie Gondolellidae LINDSTROM, 1970 mit Neogondolella navicula (HUCKRIEDE, 1958), und mit den problematischen Enantiognathus petraeviridis and Enantiognatus ziegleri (DIESEL, 1956)?. Die quantitative Auswertu ng der Conodontenelemente zeigt ei ne eindeutige Vorherrschaft der Enantiognathiformen Elemente und Neogondolellaceen Form en im Verhaltnis zu Ellison/a and Gladidondolella, was als EinfluB der Fazies gedeutet oder/und als eine Evolutionstendenz angesehen werden kann.
Abstract The Ladinian Buchenstein (Livinallongo) Formation has been studied near Vigo di Fassa, Dolomites, Southern Alps (ltaly)c The well-preserved conodont fauna includes representatives of the family Ellisonidae MOLLER, 1956 with El/isonia triassica MOLLER, 1956? and Gladigondolella tethydis (HucKRIEDE, 1958), the family Gondolellidae LINDSTROM, 1970 with Neogondolella navicula (HUCKRIEDE, 1958), and the problematic Enantiognathus petraeviridis and Enantiognatus ziegleri (DI EBEL, 1956)?. The quantitative analysis of the conodont elements shows a clear predominance of Enantiognathiform elements and Neogondolellacean forms compared to Ellisonia and Gladidondolella, with a probable implication on biofacies or/and evolution.
1. Introduction The study area is situated in Val di Fassa, in the western part of the Dolomites, northern Italy (Text-Fig. 1). The Triassic sequences in this area, overlying the uppermost Permian Bellerophon Formation, range from the Scythian
Werfen Formation at the base to the thick and massive Ladinian buildups at the top (Text-Fig. 2). The described specimens are from the Ladinian Buchenstein Formation, which is subdivided into three members: The Plattenkalk,
*) Author's address: ELIAS SAMANKAssou, lnstitut tor Palaontologie, Universitat Erlangen Nurnberg, LoewenichstraBe 28, D-91054 Erlangen.
523
-J~
~armolada /~J Predazzo
NTO ~~
ofMonzoni
responds to primary volcanogenic beds termed, according to their green color, "Piedra verde" (RICHTHOFEN, 1859, in OBENHOLZNER & PFEIFER, 1991). These sediments (Knollenkalk) correspond to slope to basin deposits. The Banderkalk is composed of resedimented calcarenites, alternating with mudstone layers and partly nodular limestones. According to BOSELLINI & STEFANI (1991), the Banderkalk was produced by the bas inward progradation of a resedimented apron. The described outcrops belong to the Knollenkalk and to the Banderkalk (Text-Fig. 3). Some samples came from blocks comprising the volcanic layers (Text-Fig. 3, section 2). The calcareous nodules yield excellently preserved conodonts. The conodont amount is high (about 20 elements/5 kg materials, s. Text-Fig. 3) in comparison with the lower Triassic sediments. The Conodont Alteration Index (CAI; EPSTEIN et al., 1977) ranges between 1-1.5 and differs from that of conodonts in the underlying formations (SAMANKASSOU, 1992).
Systematic Paleontology
Intrusion of Predazzo
Text-Fig. 1. Location of the study area.
the Knollenkalk and the Banderkalk. The Plattenkalk is of bituminous mudstones, fine-grained doloand radiolarian-rich laminae. It has been interas an anoxia deposit (BOSELLINI & STEFANI, 1991 ). The Knollenkalk is formed of cherty nodular limestones, with interbeds. The nodules correspond to primary calcareous the green matrix is diagenetic and cor-
Mannolada Limestone
Volcanic Layers
Ladinian
TRIASSIC
Mocna Formation
Anisian Richthofen Conglomernt
Werfen Formation
The complete synonymy is not always given. In describing the conodont fauna, multielement taxonomy is applied by clearly identifiable elements. The described and figured specimens, part of the author's Diploma Thesis (SAMANKASSOU, 1992), are deposited at the Geological Institute of the University of Erlangen (Germany).
Phylum: Conodonta PANDER, 1856 Class: Conodonti BRANSON,1938 Prioniodinida SWEET, 1988 Family: Ellisonidae CLARK, 1972 Genus: El!isonia MOLLER, 1956 Type species: Ellisonia triassica MOLLER, 1956.
Ellisonia triassica MOLLER,
1956?
(Pl. 1, Fig. 13) 1970 E//isonia triassica MOLLER- SWEET, p. 235, Pl. 5, Fig. 9, 13-15, 17, 18, 20-22. 1981 Ellisonia triassica MOLLER - SWEET, p. W152, Fig. 3 a-f. 1987 E//isonia triassica MOLLER - PERRI & ANDRAGHETTI, p. 305-306. 1995 Ellisonia triassica MOLLER - SAMANKASSOU, p. 252 and 254, Fig. 5 (5).
Rem arks: E//isonia MOLLER, 1956 is seen in the present paper as synonym to Neohindeodella KozuR, 1968. The elements we found are very fragile. Two to three small denticles are interspersed between big ones. All denticles bend in the same direction. The cusp is missing. These elements are very similar to those described from the Salt Range by SWEET (1970).
us:
1
Type species: Po!ygnathus tethydis HUCKRIEDE, 1958.
Bellerophon Formation Text-Fig. 2. Stratigraphical table of the Upper Permian-Triassic sequence of the study area.
(Pl. 1, Fig. 11, 12) 1958 Polygnathus tethydis HUCKRIEDE, p. 157, Pl. 11, Fig. 39, 40; Pl. 12, Fig. 38; Pl. 13, Fig. 2, 4, 5; ?Pl. 12, Fig. 1.
Text-Fig. 3. Detailed sections of the two profiles represented in Text-Fig. 1.
section 1 samples VF-Bu
section 2 samples VFK-Bu
1966 Gladigondolella tethydis (HUCKRIEDE) - ISHll & NOGAMI, Pl. 1, Fig.1, non Fig. 2. 1980 G!adigondolella tethydis (HUCKRIEDE) - KOVACS & KOZUR, Pl. 3, Fig. 5, 6. 1984 G!adigondolella tethydis (HUCKRIEDE) VRIELYNCK, p. 184, Pl. 2, Fig. 4. 1986 Gladigondolella tethydis (HUCKRIEDE) - 0URKOOP et al., Pl. 18, Fig. 5, 6, ?7-11, 12-15. 1986 Gladigondo!ella tethydis (HUCKRIEDE) - SUDAR, Pl. 8, Fig. 5, 6. 1988 Gladigondolella tethydis (HUCKRIEDE) - PFEIFER, Pl. 13, Fig. 1-4. 1991 Gladigondolella tethydis (HUCKRIEDE) - KOLARJURKOVSEK, p.90, Pl. 16, Fig. 2, 5; Pl. 24, Fig. 1,
- 8-11 * - 6-7*
19 * - 18*
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