scholarly journals Eruption Mechanism and Volatile Budget of the Early Eocene Danish Ash Series, and Implications for the Emplacement of the North Atlantic Igneous Province

2020 ◽  
Author(s):  
Ella Wulfsberg Stokke ◽  
Emma J. Liu ◽  
Morgan Jones
Keyword(s):  
North Atlantic ◽  
Early Eocene ◽  
The North ◽  
Igneous Province ◽  
The North Atlantic ◽  
North Atlantic Igneous Province

Astronomical calibration of a key Early Eocene Boreal section: implications for the climate response to the North Atlantic Igneous Province

2021 ◽  
Author(s):  
Nicolas Thibault ◽  
Thierry Adatte ◽  
Jorge E. Spangenberg
Keyword(s):  
Magnetic Susceptibility ◽  
North Sea ◽  
North Atlantic ◽  
Fish Fauna ◽  
Early Eocene ◽  
The North ◽  
Igneous Province ◽  
The North Sea ◽  
The North Atlantic ◽  
North Atlantic Igneous Province

<p>Sections of the Fur formation exposed on the islands of Fur and Mors (N. Jutland, Denmark) expose well-preserved diatomites and over 140 interbedded ash layers spanning >1 Myr of the Early Eocene from the top part of the Paleocene-Eocene Thermal Maximum (PETM; 55.9 Ma). The Fur Formation is a Konzentrat-Lagerstätten with an extremely rich fish fauna as well as numerous exquisitely preserved invertebrates, vertebrates, plant material, and siliceous microfossils. Due to its peculiar bentonite record, the Fur formation also constitutes a reference for the North Sea area, recording phases of active North Atlantic Igneous Province (NAIP) volcanism. Recently, a sea-surface temperature (SST) record was derived from Tex<sub>86</sub> values for this formation, showing anomalously cool SSTs immediately after the PETM (~11–23°C, Stokke et al., 2020) while near-freezing bottom-water temperatures (BWTs) have been inferred from clumped isotopes analysis of giant glendonite crystals (Vickers et al., 2020). The section is constrained by three radiometric dates of ash layers but cyclostratigraphic analysis of the section has proved difficult due to the apparent homogeneity of the diatomite and multitude of interbedded ash layers. We performed a high-resolution analysis of the magnetic susceptibility and carbon isotopes on bulk organics (δ<sup>13</sup>C<sub>org</sub>) from across the top PETM to the top of the Silstrup Mb. The magnetic susceptibility depicts all the apparent ash layers as well as additional hidden ash layers with peaks of various heights, and thus constitutes an excellent stratigraphic tool for its potential of correlation to other sections and deep-sea sites of the North Atlantic. Our δ<sup>13</sup>C<sub>org </sub>record is characterized throughout by periodicities of 65 to 90 cm and 3.6 m that match well precession and short-eccentricity cycles. Long-term trends and filtered 100 kyr cycles from our record correlate very well to the recent benthic δ<sup>13</sup>C Cenozoic compilation, leading to an astronomical calibration of the section which spans ~1300 kyr from 55.88 to 54.6 Ma. Our calibration allows for a precise illustration of the drastic contrast between the post-PETM warm tropical SSTs/BWTs and the surprisingly cool SSTs/BWTs of the North Sea.</p><p>References</p><p>Stokke, E.W., et al., 2020, Earth and Planetary Science Letters 544, 116388.</p><p>Vickers, M.L., et al., 2020, Nature Communications 11, 4713.</p>

Enhanced volcanism associated to the emplacement of the North Atlantic Igneous Province during the PETM evidenced by mercury anomalies in Pyrenean foreland sections

2021 ◽  
Author(s):  
Maxime Tremblin ◽  
Hassan Khozyem ◽  
Jorge E. Spangenberg ◽  
Charlotte Fillon ◽  
Sylvain Calassou ◽  
...  
Keyword(s):  
North Atlantic ◽  
External Perturbation ◽  
The North ◽  
Sequence Of Events ◽  
Source To Sink ◽  
Large Perturbation ◽  
Igneous Province ◽  
Multiple Pulses ◽  
The North Atlantic ◽  
North Atlantic Igneous Province

<p>The Paleocene-Eocene thermal maximum (PETM; ~55.6 Ma) is one of the most pronounced and the best known of the transient hyperthermal events of the Paleogene. The PETM is characterized by global warming, a significant perturbation of the carbon cycle, and a large perturbation of the biosphere. This extraordinary event is recorded by sharp negative carbon excursions (NCIE) in both oceanic and terrestrial carbonates. The sequence of events triggering this disturbance and the source of the <sup>13</sup>C-depleted carbon for the NCIE remains controversial. External perturbation such as volcanism, associated with the setup of the North Atlantic Igneous Province (NAIP), is suspected to be one of the mechanisms responsible for this abrupt climate upheaval. One proxy for investigating the possible link between the establishment of the NAIP and perturbation associated with the PETM is to study mercury (Hg) concentrations record in marine and continental sedimentary successions.</p><p>In this study, we present new high-resolution mercury and stable isotopic records from peripheral basins of the Pyrenean orogen across the PETM. The four studies sections vary from continental to bathyal deposit environment and offer the potential to evaluate how major climatic disturbances are associated with the PETM record through a continental to marine transect.</p><p>The data obtained reveal the occurrence of two main NCIEs. Based on biostratigraphy and similarity of shape and amplitude of the isotopic excursions with global records, the largest NCIE is interpreted as the PETM. This sharp excursion is preceded by another one that we interpreted as the Pre-Onset Excursion (POE), founded in some other profiles worldwide. These two NCIEs are systematically associated with important mercury anomalies, whatever the environment considered. Increase in Hg contents shows no correlation with clay or total organic carbon contents, suggesting that the influences of local processes or Hg scavenging by organic matter appear to be insignificant. These results show that multiple pulses of volcanism, probably associated with the emplacement of the NAIP, contributed to the onset and the long duration of the PETM. In addition, our study highlights the possibility to get reliable information about past extreme climate events from sedimentary successions even if deposited within active tectonic domains.</p><p>This work is financed and carried out within the framework of the BRGM-TOTAL Source-to-Sink project.</p>

scholarly journals The onset of the North Atlantic Igneous Province in a rifting perspective

2009 ◽  
Vol 146 (3) ◽  
pp. 309-325 ◽  
Author(s):  
J. HANSEN ◽  
D. A. JERRAM ◽  
K. McCAFFREY ◽  
S. R. PASSEY
Keyword(s):  
North Atlantic ◽  
Regional Scale ◽  
The North ◽  
Time Space ◽  
Lithospheric Extension ◽  
Igneous Province ◽  
The North Atlantic ◽  
North Atlantic Igneous Province ◽  
North Atlantic Area ◽  
Atlantic Area

AbstractThe processes that led to the onset and evolution of the North Atlantic Igneous Province (NAIP) have been a theme of debate in the past decades. A popular theory has been that the impingement on the lower lithosphere of a hot mantle plume (the ‘Ancestral Iceland’ plume) initiated the first voluminous outbursts of lava and initiated rifting in the North Atlantic area in Early Palaeogene times. Here we review previous studies in order to set the NAIP magmatism in a time–space context. We suggest that global plate reorganizations and lithospheric extension across old orogenic fronts and/or suture zones, aided by other processes in the mantle (e.g. local or regional scale upwellings prior to and during the final Early Eocene rifting), played a role in the generation of the igneous products recorded in the NAIP for this period. These events gave rise to the extensive Paleocene and Eocene igneous rocks in W Greenland, NW Britain and at the conjugate E Greenland–NW European margins. Many of the relatively large magmatic centres of the NAIP were associated with transient and geographically confined doming in Early Paleocene times prior to the final break-up of the North Atlantic area.

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