41 research outputs found
Cold spells in the Nordic Seas during the early Eocene Greenhouse
Abstract The early Eocene (c. 56 - 48 million years ago) experienced some of the highest global temperatures in Earth’s history since the Mesozoic, with no polar ice. Reports of contradictory ice-rafted erratics and cold water glendonites in the higher latitudes have been largely dismissed due to ambiguity of the significance of these purported cold-climate indicators. Here we apply clumped isotope paleothermometry to a traditionally qualitative abiotic proxy, glendonite calcite, to generate quantitative temperature estimates for northern mid-latitude bottom waters. Our data show that the glendonites of the Danish Basin formed in waters below 5 °C, at water depths of <300 m. Such near-freezing temperatures have not previously been reconstructed from proxy data for anywhere on the early Eocene Earth, and these data therefore suggest that regionalised cool episodes punctuated the background warmth of the early Eocene, likely linked to eruptive phases of the North Atlantic Igneous Province.</jats:p
Late Famennian correlation by miospores between the Refrath 1 Borehole (Bergisch Gladbach-Paffrath Syncline, Germany) and the reference section of Chanxhe (Dinant Syncline, Belgium).
The Bergisch Gladbach-Paffrath Syncline and the Dinant Syncline are both part of the Ardennes-Rhenish Massif but are separated by some 100 km. In the Upper Devonian succession of the Bergisch Gladbach-Paffrath Syncline (The Bergisches Land), the Knoppenbissen Formation is assigned the "Dasbergian" (Hartkoph-Fröder et alii, 2004). In this syncline the thermal alteration index (TAI of 2 to 2+) is remarkably low compared to that of other Upper Devonian sediments in the Ardenne-Rhenisch area
Late Famennian miospore assemblages from the Bergisch Gladbach - Paffrath Syncline, Rhenish Slate Mountains, Germany
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