Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences
At two locations in the Atlantic Ocean (DSDP Sites 367 and 530) early to middle Cretaceous organic-carbon-rich beds (black shales) were found to have significantly lower delta15N values (lower 15N/14N ratios) than adjacent organic-carbon-poor beds (white limestones or green claystones). While these...
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1987
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.714244 2023-05-15T17:35:15+02:00 Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences Rau, Greg H Arthur, Michael A Dean, Walter E MEDIAN LATITUDE: 9.598100 * MEDIAN LONGITUDE: -26.896633 * SOUTH-BOUND LATITUDE: -19.187700 * WEST-BOUND LONGITUDE: -70.028500 * NORTH-BOUND LATITUDE: 35.495200 * EAST-BOUND LONGITUDE: 9.385800 * DATE/TIME START: 1975-03-03T00:00:00 * DATE/TIME END: 1983-05-05T00:00:00 1987-03-30 application/zip, 3 datasets https://doi.pangaea.de/10.1594/PANGAEA.714244 https://doi.org/10.1594/PANGAEA.714244 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.714244 https://doi.org/10.1594/PANGAEA.714244 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Rau, Greg H; Arthur, Michael A; Dean, Walter E (1987): 15N/14N variations in Cretaceous Atlantic sedimentary sequences: implication for past changes in marine nitrogen biogeochemistry. Earth and Planetary Science Letters, 82(3-4), 269-279, https://doi.org/10.1016/0012-821X(87)90201-9 41-367 75-530A 93-603B Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg41 Leg75 Leg93 North Atlantic/BASIN South Atlantic/RIDGE Dataset 1987 ftpangaea https://doi.org/10.1594/PANGAEA.714244 https://doi.org/10.1016/0012-821X(87)90201-9 2023-01-20T07:31:23Z At two locations in the Atlantic Ocean (DSDP Sites 367 and 530) early to middle Cretaceous organic-carbon-rich beds (black shales) were found to have significantly lower delta15N values (lower 15N/14N ratios) than adjacent organic-carbon-poor beds (white limestones or green claystones). While these lithologies are of marine origin, the black strata in particular have delta15N values that are significantly lower than those previously found in the marine sediment record and most contemporary marine nitrogen pools. In contrast, black, organic-carbon-rich beds at a third site (DSDP Site 603) contain predominantly terrestrial organic matter and have C- and N-isotopic compositions similar to organic matter of modern terrestrial origin. The recurring 15N depletion in the marine-derived Cretaceous sequences prove that the nitrogen they contain is the end result of an episodic and atypical biogeochemistry. Existing isotopic and other data indicate that the low 15N relative abundance is the consequence of pelagic rather than post-depositional processes. Reduced ocean circulation, increased denitrification, and, hence, reduced euphoric zone nitrate availability may have led to Cretaceous phytoplankton assemblages that were periodically dominated by N2-fixing blue-green algae, a possible source of this sediment 15N-depletion. Lack of parallel isotopic shifts in Cretaceous terrestrially-derived nitrogen (Site 603) argues that the above change in nitrogen cycling during this period did not extend beyond the marine environment. Dataset North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-70.028500,9.385800,35.495200,-19.187700) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
41-367 75-530A 93-603B Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg41 Leg75 Leg93 North Atlantic/BASIN South Atlantic/RIDGE |
spellingShingle |
41-367 75-530A 93-603B Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg41 Leg75 Leg93 North Atlantic/BASIN South Atlantic/RIDGE Rau, Greg H Arthur, Michael A Dean, Walter E Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences |
topic_facet |
41-367 75-530A 93-603B Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg41 Leg75 Leg93 North Atlantic/BASIN South Atlantic/RIDGE |
description |
At two locations in the Atlantic Ocean (DSDP Sites 367 and 530) early to middle Cretaceous organic-carbon-rich beds (black shales) were found to have significantly lower delta15N values (lower 15N/14N ratios) than adjacent organic-carbon-poor beds (white limestones or green claystones). While these lithologies are of marine origin, the black strata in particular have delta15N values that are significantly lower than those previously found in the marine sediment record and most contemporary marine nitrogen pools. In contrast, black, organic-carbon-rich beds at a third site (DSDP Site 603) contain predominantly terrestrial organic matter and have C- and N-isotopic compositions similar to organic matter of modern terrestrial origin. The recurring 15N depletion in the marine-derived Cretaceous sequences prove that the nitrogen they contain is the end result of an episodic and atypical biogeochemistry. Existing isotopic and other data indicate that the low 15N relative abundance is the consequence of pelagic rather than post-depositional processes. Reduced ocean circulation, increased denitrification, and, hence, reduced euphoric zone nitrate availability may have led to Cretaceous phytoplankton assemblages that were periodically dominated by N2-fixing blue-green algae, a possible source of this sediment 15N-depletion. Lack of parallel isotopic shifts in Cretaceous terrestrially-derived nitrogen (Site 603) argues that the above change in nitrogen cycling during this period did not extend beyond the marine environment. |
format |
Dataset |
author |
Rau, Greg H Arthur, Michael A Dean, Walter E |
author_facet |
Rau, Greg H Arthur, Michael A Dean, Walter E |
author_sort |
Rau, Greg H |
title |
Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences |
title_short |
Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences |
title_full |
Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences |
title_fullStr |
Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences |
title_full_unstemmed |
Nitrogen isotope ratios of Cretaceous Atlantic sedimentary sequences |
title_sort |
nitrogen isotope ratios of cretaceous atlantic sedimentary sequences |
publisher |
PANGAEA |
publishDate |
1987 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.714244 https://doi.org/10.1594/PANGAEA.714244 |
op_coverage |
MEDIAN LATITUDE: 9.598100 * MEDIAN LONGITUDE: -26.896633 * SOUTH-BOUND LATITUDE: -19.187700 * WEST-BOUND LONGITUDE: -70.028500 * NORTH-BOUND LATITUDE: 35.495200 * EAST-BOUND LONGITUDE: 9.385800 * DATE/TIME START: 1975-03-03T00:00:00 * DATE/TIME END: 1983-05-05T00:00:00 |
long_lat |
ENVELOPE(-70.028500,9.385800,35.495200,-19.187700) |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Supplement to: Rau, Greg H; Arthur, Michael A; Dean, Walter E (1987): 15N/14N variations in Cretaceous Atlantic sedimentary sequences: implication for past changes in marine nitrogen biogeochemistry. Earth and Planetary Science Letters, 82(3-4), 269-279, https://doi.org/10.1016/0012-821X(87)90201-9 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.714244 https://doi.org/10.1594/PANGAEA.714244 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.714244 https://doi.org/10.1016/0012-821X(87)90201-9 |
_version_ |
1766134357588705280 |