scholarly journals Nd and Sr isotope compositions from the Gardiner Complex, East Greenland Tertiary igneous province

1993 ◽  
Vol 40 ◽  
pp. 280-287
Author(s):  
Troels F. D. Nielsen ◽  
Paul M. Holm
Keyword(s):  
Isotopic Composition ◽  
North Atlantic ◽  
Alkaline Magmatism ◽  
Sr Isotope ◽  
East Greenland ◽  
The North ◽  
Early Tertiary ◽  
Igneous Province ◽  
The North Atlantic

The Gardiner Complex formed during the early Tertiary opening of the North Atlantic. The complex is strongly alkaline and referred to a zone of alkaline flank magmatism 100 km west of the melting anomaly in the initial rift of the North Atlantic. Earlier investigations have documented that most rocks of the complex can be referred to three suites which are all suggested to have been formed from a single parental melanephelinitic liquid. The Nd and Sr isotope compositions presented here support this conclusion. Minor deviations are believed to be due to interaction with Archaean basement. The isotopic characteristics suggest that the alkaline magmatism originated in a source similar to that of the contemporaneous picritic and basaltic tholeiites. The isotopic composition of the source is Jess depleted than pervalent mantle (PREMA) and sets an upper enrichment limit to the composition of the Icelandic plume component 50 Ma ago.

U–Pb geochronology of the Eocene Kærven intrusive complex, East Greenland: constraints on the Iceland hotspot track during the rift-to-drift transition

2015 ◽  
Vol 153 (1) ◽  
pp. 128-142 ◽  
Author(s):  
SIGURJÓN B. THÓRARINSSON ◽  
PAUL M. HOLM ◽  
SEBASTIAN TAPPE ◽  
LARRY M. HEAMAN ◽  
NIELS-OLE PRÆGEL
Keyword(s):  
North Atlantic ◽  
Large Igneous Province ◽  
Alkaline Magmatism ◽  
Ionization Mass ◽  
Skaergaard Intrusion ◽  
East Greenland ◽  
The North ◽  
The North Atlantic ◽  
Complex Forms ◽  
Absolute Age

AbstractSeveral major tholeiitic (e.g. the Skaergaard intrusion) and alkaline (e.g. the Kangerlussuaq Syenite) intrusive complexes of the North Atlantic Large Igneous Province are exposed along the Kangerlussuaq Fjord in East Greenland. The Kærven Complex forms a satellite intrusion to the Kangerlussuaq Syenite and includes early tholeiitic gabbros and a series of cross-cutting alkaline intrusions ranging from monzonite to alkali granite. The alkaline intrusions cut the gabbros, and are cut by the outer nordmarkite zone of the Kangerlussuaq Syenite. This study presents the first U–Pb zircon ages from the alkaline units of the Kærven Complex. Fourteen multi-grain zircon fractions have been analysed by thermal ionization mass spectrometry (TIMS). Absolute age differences could not be resolved between the different units, suggesting a relatively rapid succession of intrusions betweenc. 53.5 and 53.3 Ma. Our compilation of precise radiometric age data shows that most of the alkaline magmatism in the Kangerlussuaq Fjord occurred prior to 50 Ma. Moreover, pre-50 Ma alkaline intrusions and lavas show a SSE-younging trend, which is interpreted as the track of the Iceland hotspot during the rift-to-drift transition of the North Atlantic.

scholarly journals C14 content of recent molluscs from Scoresby Sund, central East Greenland

1975 ◽  
Vol 75 ◽  
pp. 95-99
Author(s):  
H Tauber ◽  
S Funder
Keyword(s):  
North Atlantic ◽  
East Coast ◽  
Marine Organisms ◽  
Water Masses ◽  
Lower Activity ◽  
Terrestrial Plants ◽  
East Greenland ◽  
The North ◽  
The North Atlantic ◽  
Turn Over

C14 dating of subfossil marine shelIs presupposes a knowledge of the original C14 activity of the organisms while living. Due to the slow turn over of water masses, the C14 activity of marine bicarbonate and marine organisms is not the same in all parts of the oceans, but may show marked deficiencies in certain oceanic areas, especially at southern latitudes. In large areas of the North Atlantic the C14 activity seems to be fairly uniform and equal to or only slightly lower than that of 'pre-industrial' terrestrial plants (Broecker et al., 1960; Mangerud, 1972; Krog & Tauber, 1974). In certain areas, however, a somewhat lower activity seems to occur; trus has been noted for areas along the east coast of Greenland (Fonselius & Ostlund, 1959; Hjort, 1973).

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>

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