The Prati di Stuores Stuores Wiesen Section (Dolomites, Italy): A candidate global stratotype section and point for the base of the Carnian stage

Citation
Cb. Loriga et al., The Prati di Stuores Stuores Wiesen Section (Dolomites, Italy): A candidate global stratotype section and point for the base of the Carnian stage, RIV IT PAL, 105(1), 1999, pp. 37-78
Citations number
111
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Earth Sciences
Journal title
RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA
ISSN journal
0035-6883 → ACNP
Volume
105
Issue
1
Year of publication
1999
Pages
37 - 78
Database
ISI
SICI code
0035-6883(199904)105:1<37:TPDSSW>2.0.ZU;2-X
Abstract
The Prati di Stuores/Stuores Wiesen section (Dolomites, Italy) is proposed as a candidate Global Stratotype Section and Point for the base of the Carn ian Stage. In addition to being a famous, richly fossiliferous locality, it includes the type-section of the Cordevolian substage. The section is loca ted near Pralongia, along the southern slope of the crest separating the Ba dia/Abtei and Cordevole valleys. Below the levels with Trachyceras aon, the section contains a rich ammonoid fauna that characterizes the upper part o f the Regoledanus Subzone and subsequently records the first appearances of the mid-high latitude genus Daxatina (Daxatina sp., D. cf. canadensis) and of traditional Trachyceras with species different from T. aon. Therefore, the Daxatina cf. canadensis Subzone is recognised above the Regoledanus Sub zone. Very rare conodonts of the Budurovignatus group and species of Gladig ondolella from the diebeli Assemblage Zone occur. Gondolella polygnathiform is, already known from the Aon Subzone, is absent. Palynomorphs, foraminife rs, gastropods, bi-valves, brachiopods, microcrinoids and holothurian scler ites were studied. Variations in frequency and taxonomic diversity of these faunas suggest anaerobic-disaerobic bottom conditions for the lower-middle part of the section (0-105 m), followed by a more stable oxygen content in the upper portion. Magnetostratigraphy showed four intervals with normal p olarity and three intervals with reversed polarity. The Daxatina cf. canade nsis Subzone falls close to the normal polarity interval S2n. The present s tudy proposes the FAD of the cosmopolitan genus Daxatina as the marker of t he base of the Carnian Stage, placing it at a lower stratigraphic level tha n previously indicated in the Stuores area. The Prati di Stuores section is proposed as GSSP of the Ladinian-Carnian boundary.