New constraints on the last aragonite-calcite sea transition from early Jurassic ooids

Journal article
(Original article)


Publication Details

Author(s): Vulpius S, Kießling W
Journal: Facies
Publisher: SPRINGER
Publication year: 2018
Volume: 64
Journal issue: 1
ISSN: 0172-9179


Abstract

Calcite and aragonite seas are commonly distinguished based on the prevailing primary mineralogy of ooids and carbonate cements over time. Secular oscillations of these seas are usually attributed to changes in ocean chemistry and paleoclimate. While the veracity of such oscillations has been verified by independent data and modeling approaches, the timing of the transition from one ocean state to the other remains poorly resolved. Here, the timing of the last aragonite-calcite sea transition is estimated by assessing the preservation of Early Jurassic ooids from the Trento Platform in northern Italy. Point counting of ooid-bearing limestones from four distinct stratigraphic levels provides a contrasting pattern: Hettangian and Sinemurian ooids are all poorly preserved and were probably predominantly originally aragonitic, whereas Pliensbachian and Toarcian ooids are excellently preserved, suggesting a primary calcitic mineralogy. Although calcitic ooids may have already been common in the Late Triassic, it is proposed that the last aragonite-calcite sea transition occurred in the Early Jurassic between the Sinemurian and Pliensbachian, at least in this subtropical region. Therefore, the selective extinction of aragonite-secreting organisms at the end-Triassic mass extinction cannot be attributed to secular changes in ocean chemistry.


FAU Authors / FAU Editors

Kießling, Wolfgang Prof. Dr.
Lehrstuhl für Paläoumwelt
Vulpius, Sara
Lehrstuhl für Endogene Geodynamik


How to cite

APA:
Vulpius, S., & Kießling, W. (2018). New constraints on the last aragonite-calcite sea transition from early Jurassic ooids. Facies, 64(1). https://dx.doi.org/10.1007/s10347-017-0516-x

MLA:
Vulpius, Sara, and Wolfgang Kießling. "New constraints on the last aragonite-calcite sea transition from early Jurassic ooids." Facies 64.1 (2018).

BibTeX: 

Last updated on 2018-11-08 at 01:28