“Short” or “long” Rhaetian ? Astronomical calibration of Austrian key sections
(2020) In Global and Planetary Change 192.- Abstract
The establishment of the Late Triassic time scale has given rise to considerable controversy, particularly regarding the Rhaetian duration and the inferred absolute age models. In this respect the astronomical polarity time scale (APTS) established from the continental successions of the Newark Basin (eastern North America) is considered as a reference record, although its completeness is questioned. Numerous magnetostratigraphic correlation schemes have been proposed between the APTS and biostratigraphically well-constrained Tethyan marine sections. This has led to two main contrasting options: a “short” Rhaetian duration (about 4–5 myr), and a “long” one (about 8–9 myr). Astronomical calibration of the Tethyan Rhaetian and estimate of... (More)
The establishment of the Late Triassic time scale has given rise to considerable controversy, particularly regarding the Rhaetian duration and the inferred absolute age models. In this respect the astronomical polarity time scale (APTS) established from the continental successions of the Newark Basin (eastern North America) is considered as a reference record, although its completeness is questioned. Numerous magnetostratigraphic correlation schemes have been proposed between the APTS and biostratigraphically well-constrained Tethyan marine sections. This has led to two main contrasting options: a “short” Rhaetian duration (about 4–5 myr), and a “long” one (about 8–9 myr). Astronomical calibration of the Tethyan Rhaetian and estimate of its duration is necessary to help advance this debate. We have undertaken a cyclostratigraphic analysis of a Rhaetian composite record built from four overlapping Austrian reference sections. Magnetic susceptibility variations of the 131.5 m thick record are astronomically paced by the precession and 405-kyr orbital eccentricity cycles. 405-kyr orbital tuning allows to establish a floating time scale, and thus to suggest a minimum duration of 6.69 myr of the Rhaetian stage. Given the well-established radioisotopic age of the Rhaetian-Hettangian boundary of 201.36 Ma, an age no younger than 208.05 Ma for the Norian-Rhaetian boundary can be proposed. This result will contribute to the refinement of the Late Triassic time scale, but it does not solve the long-standing debate on bio-magnetostratigraphic correlations between the continental Newark APTS and the Tethyan marine sections, nor the question of the completeness of the Rhaetian Newark Basin.
(Less)
- author
- Galbrun, Bruno ; Boulila, Slah ; Krystyn, Leopold ; Richoz, Sylvain LU ; Gardin, Silvia ; Bartolini, Annachiara and Maslo, Martin
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- 405 kyr eccentricity tuning, Cyclostratigraphy, Late Triassic time scale, Magnetic susceptibility, Northern Calcareous Alps, Rhaetian
- in
- Global and Planetary Change
- volume
- 192
- article number
- 103253
- publisher
- Elsevier
- external identifiers
-
- scopus:85086522695
- ISSN
- 0921-8181
- DOI
- 10.1016/j.gloplacha.2020.103253
- language
- English
- LU publication?
- yes
- id
- 3593aa68-df15-44b9-8505-beff727d713f
- date added to LUP
- 2020-06-30 12:22:56
- date last changed
- 2023-02-28 15:44:51
@article{3593aa68-df15-44b9-8505-beff727d713f,
abstract = {{<p>The establishment of the Late Triassic time scale has given rise to considerable controversy, particularly regarding the Rhaetian duration and the inferred absolute age models. In this respect the astronomical polarity time scale (APTS) established from the continental successions of the Newark Basin (eastern North America) is considered as a reference record, although its completeness is questioned. Numerous magnetostratigraphic correlation schemes have been proposed between the APTS and biostratigraphically well-constrained Tethyan marine sections. This has led to two main contrasting options: a “short” Rhaetian duration (about 4–5 myr), and a “long” one (about 8–9 myr). Astronomical calibration of the Tethyan Rhaetian and estimate of its duration is necessary to help advance this debate. We have undertaken a cyclostratigraphic analysis of a Rhaetian composite record built from four overlapping Austrian reference sections. Magnetic susceptibility variations of the 131.5 m thick record are astronomically paced by the precession and 405-kyr orbital eccentricity cycles. 405-kyr orbital tuning allows to establish a floating time scale, and thus to suggest a minimum duration of 6.69 myr of the Rhaetian stage. Given the well-established radioisotopic age of the Rhaetian-Hettangian boundary of 201.36 Ma, an age no younger than 208.05 Ma for the Norian-Rhaetian boundary can be proposed. This result will contribute to the refinement of the Late Triassic time scale, but it does not solve the long-standing debate on bio-magnetostratigraphic correlations between the continental Newark APTS and the Tethyan marine sections, nor the question of the completeness of the Rhaetian Newark Basin.</p>}},
author = {{Galbrun, Bruno and Boulila, Slah and Krystyn, Leopold and Richoz, Sylvain and Gardin, Silvia and Bartolini, Annachiara and Maslo, Martin}},
issn = {{0921-8181}},
keywords = {{405 kyr eccentricity tuning; Cyclostratigraphy; Late Triassic time scale; Magnetic susceptibility; Northern Calcareous Alps; Rhaetian}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Global and Planetary Change}},
title = {{“Short” or “long” Rhaetian ? Astronomical calibration of Austrian key sections}},
url = {{http://dx.doi.org/10.1016/j.gloplacha.2020.103253}},
doi = {{10.1016/j.gloplacha.2020.103253}},
volume = {{192}},
year = {{2020}},
}