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Glendonite occurrences in the Tremadocian of Baltica: first Early Palaeozoic evidence of massive ikaite precipitation at temperate latitudes

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dc.contributor.author Popov L.
dc.contributor.author Álvaro J.
dc.contributor.author Holmer L.
dc.contributor.author Bauert H.
dc.contributor.author Ghobadi Pour M.
dc.contributor.author Dronov A.
dc.contributor.author Lehnert O.
dc.contributor.author Hints O.
dc.contributor.author Männik P.
dc.contributor.author Zhang Z.
dc.date.accessioned 2020-01-15T22:10:17Z
dc.date.available 2020-01-15T22:10:17Z
dc.date.issued 2019
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/156840
dc.description.abstract © 2019, The Author(s). 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 18 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 3 ·6H 2 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 18 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.
dc.title Glendonite occurrences in the Tremadocian of Baltica: first Early Palaeozoic evidence of massive ikaite precipitation at temperate latitudes
dc.type Article
dc.relation.ispartofseries-issue 1
dc.relation.ispartofseries-volume 9
dc.collection Публикации сотрудников КФУ
dc.source.id SCOPUS-2019-9-1-SID85065639455


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  • Публикации сотрудников КФУ Scopus [24551]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

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