The post-basaltic Palaeogene and Neogene sediments at Kap Dalton and Savoia Halvø, East Greenland

Author(s):  
Michael Larsen ◽  
Stefan Piasecki ◽  
Lars Stemmerik

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Larsen, M., Piasecki, S., & Stemmerik, L. (2002). The post-basaltic Palaeogene and Neogene sediments at Kap Dalton and Savoia Halvø, East Greenland. Geology of Greenland Survey Bulletin, 191, 103-110. https://doi.org/10.34194/ggub.v191.5136 _______________ The Palaeogene flood basalts in East Greenland are part of the North Atlantic Igneous Province (NAIP) formed during continental rifting and opening of the northern North Atlantic (Saunders et al. 1997). Along the Blosseville Kyst in southern and central East Greenland the basalts are exposed onshore from Kangerlussuaq in the south to Scoresby Sund in the north (Larsen et al. 1989). The base of the volcanic succession is exposed at Kangerlussuaq and at Savoia Halvø whereas post-basaltic sediments are found at two isolated localities, Kap Dalton and Savoia Halvø (Fig. 2). These three outcrop areas are thus key sources for biostratigraphic data to constrain the onset and duration of the Palaeogene volcanism in East Greenland, and are widely used in reconstructions of the North Atlantic region during continental break-up (e.g. Clift et al. 1998; Dam et al. 1999). In August 2001 the Geological Survey of Denmark and Greenland (GEUS) carried out field work in the sedimentary successions at Kap Dalton and Savoia Halvø. This was the first visit by geologists to Kap Dalton since 1975, and it is expected that the new data will provide important new biostratigraphic information and help to refine models for the Palaeogene of the North Atlantic. This report, and the palynological study of the sediments immediately below the basalts at Savoia Halvø presented by Nøhr-Hansen & Piasecki (2002, this volume), present the preliminary results of the field work.

1975 ◽  
Vol 75 ◽  
pp. 95-99
Author(s):  
H Tauber ◽  
S Funder

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).


2021 ◽  
Author(s):  
Maxime Tremblin ◽  
Hassan Khozyem ◽  
Jorge E. Spangenberg ◽  
Charlotte Fillon ◽  
Sylvain Calassou ◽  
...  

<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>


2019 ◽  
Vol 116 (27) ◽  
pp. 13227-13232 ◽  
Author(s):  
Petar Glišović ◽  
Alessandro M. Forte

The North Atlantic Igneous Province (NAIP) erupted in two major pulses that coincide with the continental breakup and the opening of the North Atlantic Ocean over a period from 62 to 54 Ma. The unknown mantle structure under the North Atlantic during the Paleocene represents a major missing link in deciphering the geodynamic causes of this event. To address this outstanding challenge, we use a back-and-forth iterative method for time-reversed global convection modeling over the Cenozoic Era which incorporates models of present-day tomography-based mantle heterogeneity. We find that the Paleocene mantle under the North Atlantic is characterized by two major low-density plumes in the lower mantle: one beneath Greenland and another beneath the Azores. These strong lower-mantle upwellings generate small-scale hot upwellings and cold downwellings in the upper mantle. The upwellings are dispersed sources of magmatism and topographic uplift that were active on the rifted margins of the North Atlantic during the formation of the NAIP. While most studies of the Paleocene evolution of the North Atlantic have focused on the proto-Icelandic plume, our Cenozoic reconstructions reveal the equally important dynamics of a hot, buoyant, mantle-wide upwelling below the Azores.


2009 ◽  
Vol 146 (3) ◽  
pp. 309-325 ◽  
Author(s):  
J. HANSEN ◽  
D. A. JERRAM ◽  
K. McCAFFREY ◽  
S. R. PASSEY

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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