2024-03-29T15:28:20Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/2090652021-12-28T15:52:03Zcom_10261_39226com_10261_8col_10261_42742
Glendonite occurrences in the Tremadocian of Baltica: first Early Palaeozoic evidence of massive ikaite precipitation at temperate latitudes
Álvaro, J.J.
Popov, Leonid E.
Holmer, Lars E.
Bauert, H.
Ghobadi Pour, Mansoureh
Dronov, A.V.
Lehnert, Oliver
Hints, O.
Männik, P.
Zhang, Zhifei
Zhang, Zhifei
Ministerio de Industria y Competitividad (España)
Estonian Research Council
Swedish Research Council
National Natural Science Foundation of China
The Tremadocian (Early Ordovician) is currently considered a time span of greenhouse conditions with tropical water surface temperature estimates, interpolated from oxygen isotopes, approaching 40 °C. In the mid-latitude Baltoscandian Basin, conodonts displaying low δ O values, which suggest high temperatures (>40 °C) in the water column, are in contrast with the discovery of contemporaneous glendonite clusters, a pseudomorph of ikaite (CaCO ·6H O) traditionally considered as indicator of near-freezing bottom-water conditions. The massive precipitation of this temperature sensitive mineral is associated with transgressive conditions and high organic productivity. As a result, the lower Tremadocian sediments of Baltoscandia apparently contain both “greenhouse” pelagic signals and near-freezing substrate indicators. This paradox points to other primary controlling mechanisms for ikaite precipitation in kerogenous substrates, such as carbonate alkalinity, pH and Mg/Ca ratios, as recently constrained by laboratory experiments. Preservation of “hot” conodonts embedded in kerogenous shales rich in δ O-depleted glendonites suggests both the onset of sharp thermal stratification patterns in a semi-closed basin and the assumed influence of isotopically depleted freshwater yielded by fluvial systems.
2020-04-25T23:57:55Z
2020-04-25T23:57:55Z
2019
2020-04-25T23:57:55Z
artículo
http://purl.org/coar/resource_type/c_6501
doi: 10.1038/s41598-019-43707-4
issn: 2045-2322
Scientific Reports 9 (2019)
http://hdl.handle.net/10261/209065
10.1038/s41598-019-43707-4
http://dx.doi.org/10.13039/501100001809
31076631
#PLACEHOLDER_PARENT_METADATA_VALUE#
info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/CGL2017-87631-P
Publisher's version
http://dx.doi.org/10.1038/s41598-019-43707-4
Sí
open
Springer Nature