"Buntsandstein" magnetostratigraphy and biostratigraphic reappraisal from eastern Iberia: Early and Middle Triassic stage boundary definitions through correlation to Tethyan sections
A new magnetic polarity stratigraphy is reported from 214 sampling sites representing 265 m of fluviatile red beds of the Buntsandstein facies succession from the Catalan Coastal Ranges (Riera de Sant Jaume, RSJ section). The Buntsandstein constitutes the lowermost of the six lithostratigraphic unit...
Published in: | Palaeogeography, Palaeoclimatology, Palaeoecology |
---|---|
Main Authors: | , , , |
Other Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2005
|
Subjects: | |
Online Access: | http://hdl.handle.net/2122/4027 https://doi.org/10.1016/j.palaeo.2005.06.036 |
Summary: | A new magnetic polarity stratigraphy is reported from 214 sampling sites representing 265 m of fluviatile red beds of the Buntsandstein facies succession from the Catalan Coastal Ranges (Riera de Sant Jaume, RSJ section). The Buntsandstein constitutes the lowermost of the six lithostratigraphic units in which the Triassic from the CCR is subdivided (also grouped into the typical three-fold subdivision of the Germanic Facies from the Tethys Realm: Buntsandstein, Muschelkalk and Keuper). Magnetostratigraphic data from four sections though the uppermost Buntsandstein facies located in the Molina de Aragón area in the Iberian Ranges (Rey, D., Turner, P., Ramos, A., 1996. Palaeomagnetism and Magnetostratigraphy of the Middle Triassic in the Iberian Ranges (Central Spain). In: Morris, A., Tarling, D.R. (Eds.), Palaeomagnetism and Tectonics of the Mediterranean Region, Geol. Soc. Sp. Pub. 105, 59–82) are also discussed in the light of a new biostratigraphic reappraisal of the palynoflora content presented herein. Characteristic magnetizations are carried mostly by hematite with minor contributions by magnetite for the Buntsandstein red beds. The magnetic polarity sequence at the RSJ section consists of 9 magnetozones (and one additional less reliable magnetozone) that are represented by more than two samples. A detailed study along a magnetic reversal indicates that the nature of the remanence in the studied red beds is partially controlled by a chemical magnetization process (delayed remanence acquisition), in addition to a detrital signature (the characteristic primary direction). Chronostratigraphic constraints are provided by conodont fauna from the overlying Muschelkalk facies that indicates a middle–late Pelsonian to late Illyrian age (middle–late Anisian) (Marquez-Aliaga, A., Valenzuela-Rios, J.I., Calvet, F., Budurov, K., 2000. Middle Triassic conodonts from northeastern Spain; biostratigraphic implications. Terra Nova 12, 77–83) and a few palynostratigraphic determinations in the Buntsandstein red beds. These ... |
---|