The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B)
Abstract We present results of an in‐situ geochemical study using laser‐ablation inductively coupled plasma–mass spectrometry ( LA ‐ ICP ‐ MS ) analyses along a ~4.3 cm long section across the K‐Pg event bed, drilled during IODP Expedition 342 at J Anomaly Ridge south of St. John's, Newfoundlan...
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crwiley:10.1111/maps.12667 2024-04-14T08:15:07+00:00 The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B) Loroch, Dominik Deutsch, Alexander Berndt, Jasper Bornemann, André 2016 http://dx.doi.org/10.1111/maps.12667 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmaps.12667 https://onlinelibrary.wiley.com/doi/pdf/10.1111/maps.12667 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Meteoritics & Planetary Science volume 51, issue 7, page 1370-1385 ISSN 1086-9379 1945-5100 Space and Planetary Science Geophysics journal-article 2016 crwiley https://doi.org/10.1111/maps.12667 2024-03-19T10:49:47Z Abstract We present results of an in‐situ geochemical study using laser‐ablation inductively coupled plasma–mass spectrometry ( LA ‐ ICP ‐ MS ) analyses along a ~4.3 cm long section across the K‐Pg event bed, drilled during IODP Expedition 342 at J Anomaly Ridge south of St. John's, Newfoundland. This section comprises the Maastrichtian with a sharp boundary to the graded, between 1.5 and 1.8 cm thick ejecta layer with totally altered impact glass spherules, which in turn is topped by Danian sediments. The porous and clayey material required elaborate preparation in order to yield reliable data. The ejecta bed shows a highly variable depletion in rare earth elements that even results in strongly subchondritic concentrations. The Ce/Ce* varies strongly (0.81–34), Ni/Cr ranges from 0.38 to 2.79. The maximum platinum group elements ( PGE ) concentrations are located in one LA ‐spot exactly at the basis of the ejecta layer; they amount (in μg g −1 ) to 0.35 (Rh), 1.64 (Pd), 2.79 (Pt), and 0.86 (Au). The Nb/Ta ratio increases in the Ma from ~10 to 35.9 toward the ejecta horizon, which itself has higher Nb, Ta, Zr, and Hf concentrations than the background sedimentation, combined with low Nb/Ta (~5–10), and low Zr/Hf (~20–30). The overall result is that alteration processes changed totally the original geochemical characteristics of this K‐Pg spherule bed. To explain the exorbitant element mobility at distances of hundreds of μm, we discuss a combination of mostly reducing redox processes and interaction with organic compounds. This study demonstrates the high potential of in‐situ analyses with high spatial resolution at complex geological materials. Moreover, our results indicate that some caution is necessary in determining the projectile type in impactites via PGE ratios. Article in Journal/Newspaper Newfoundland Wiley Online Library Meteoritics & Planetary Science 51 7 1370 1385 |
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Wiley Online Library |
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English |
topic |
Space and Planetary Science Geophysics |
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Space and Planetary Science Geophysics Loroch, Dominik Deutsch, Alexander Berndt, Jasper Bornemann, André The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B) |
topic_facet |
Space and Planetary Science Geophysics |
description |
Abstract We present results of an in‐situ geochemical study using laser‐ablation inductively coupled plasma–mass spectrometry ( LA ‐ ICP ‐ MS ) analyses along a ~4.3 cm long section across the K‐Pg event bed, drilled during IODP Expedition 342 at J Anomaly Ridge south of St. John's, Newfoundland. This section comprises the Maastrichtian with a sharp boundary to the graded, between 1.5 and 1.8 cm thick ejecta layer with totally altered impact glass spherules, which in turn is topped by Danian sediments. The porous and clayey material required elaborate preparation in order to yield reliable data. The ejecta bed shows a highly variable depletion in rare earth elements that even results in strongly subchondritic concentrations. The Ce/Ce* varies strongly (0.81–34), Ni/Cr ranges from 0.38 to 2.79. The maximum platinum group elements ( PGE ) concentrations are located in one LA ‐spot exactly at the basis of the ejecta layer; they amount (in μg g −1 ) to 0.35 (Rh), 1.64 (Pd), 2.79 (Pt), and 0.86 (Au). The Nb/Ta ratio increases in the Ma from ~10 to 35.9 toward the ejecta horizon, which itself has higher Nb, Ta, Zr, and Hf concentrations than the background sedimentation, combined with low Nb/Ta (~5–10), and low Zr/Hf (~20–30). The overall result is that alteration processes changed totally the original geochemical characteristics of this K‐Pg spherule bed. To explain the exorbitant element mobility at distances of hundreds of μm, we discuss a combination of mostly reducing redox processes and interaction with organic compounds. This study demonstrates the high potential of in‐situ analyses with high spatial resolution at complex geological materials. Moreover, our results indicate that some caution is necessary in determining the projectile type in impactites via PGE ratios. |
format |
Article in Journal/Newspaper |
author |
Loroch, Dominik Deutsch, Alexander Berndt, Jasper Bornemann, André |
author_facet |
Loroch, Dominik Deutsch, Alexander Berndt, Jasper Bornemann, André |
author_sort |
Loroch, Dominik |
title |
The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B) |
title_short |
The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B) |
title_full |
The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B) |
title_fullStr |
The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B) |
title_full_unstemmed |
The Cretaceous/Paleogene (K‐Pg) boundary at the J Anomaly Ridge, Newfoundland (<scp>IODP</scp> Expedition 342, Hole U1403B) |
title_sort |
cretaceous/paleogene (k‐pg) boundary at the j anomaly ridge, newfoundland (<scp>iodp</scp> expedition 342, hole u1403b) |
publisher |
Wiley |
publishDate |
2016 |
url |
http://dx.doi.org/10.1111/maps.12667 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmaps.12667 https://onlinelibrary.wiley.com/doi/pdf/10.1111/maps.12667 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Meteoritics & Planetary Science volume 51, issue 7, page 1370-1385 ISSN 1086-9379 1945-5100 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/maps.12667 |
container_title |
Meteoritics & Planetary Science |
container_volume |
51 |
container_issue |
7 |
container_start_page |
1370 |
op_container_end_page |
1385 |
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1796313381989253120 |