Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma
Many species of planktonic foraminifera show distinct banding in the intratest distribution of Mg/Ca. This heterogeneity appears biologically controlled and thus poses a challenge to Mg/Ca paleothermometry. The cause of this banding and its relation with chamber formation are poorly constrained and...
Published in: | Earth and Planetary Science Letters |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2016
|
Subjects: | |
Online Access: | https://orca.cardiff.ac.uk/id/eprint/93407/ https://doi.org/10.1016/j.epsl.2016.07.030 https://orca.cardiff.ac.uk/id/eprint/93407/1/Npac_EPMA_rev2_final.pdf |
id |
ftunivcardiff:oai:https://orca.cardiff.ac.uk:93407 |
---|---|
record_format |
openpolar |
spelling |
ftunivcardiff:oai:https://orca.cardiff.ac.uk:93407 2023-05-15T17:14:55+02:00 Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma Jonkers, Lukas Buse, Ben Brummer, Geert-Jan A. Hall, Ian Robert 2016-10-01 application/pdf https://orca.cardiff.ac.uk/id/eprint/93407/ https://doi.org/10.1016/j.epsl.2016.07.030 https://orca.cardiff.ac.uk/id/eprint/93407/1/Npac_EPMA_rev2_final.pdf en eng Elsevier https://orca.cardiff.ac.uk/id/eprint/93407/1/Npac_EPMA_rev2_final.pdf Jonkers, Lukas https://orca.cardiff.ac.uk/view/cardiffauthors/A642653Q.html orcid:0000-0002-0253-2639 orcid:0000-0002-0253-2639, Buse, Ben, Brummer, Geert-Jan A. and Hall, Ian Robert https://orca.cardiff.ac.uk/view/cardiffauthors/A002402L.html orcid:0000-0001-6960-1419 orcid:0000-0001-6960-1419 2016. Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma. Earth and Planetary Science Letters 451 , pp. 177-184. 10.1016/j.epsl.2016.07.030 https://doi.org/10.1016/j.epsl.2016.07.030 file https://orca.cardiff.ac.uk/id/eprint/93407/1/Npac_EPMA_rev2_final.pdf doi:10.1016/j.epsl.2016.07.030 cc_by_nc_nd CC-BY-NC-ND Article PeerReviewed 2016 ftunivcardiff https://doi.org/10.1016/j.epsl.2016.07.030 2022-11-03T23:39:56Z Many species of planktonic foraminifera show distinct banding in the intratest distribution of Mg/Ca. This heterogeneity appears biologically controlled and thus poses a challenge to Mg/Ca paleothermometry. The cause of this banding and its relation with chamber formation are poorly constrained and most of what we know about intratest Mg/Ca variability stems from culture studies of tropical, symbiont-bearing foraminifera. Here we present data on the non-spinose, symbiont-barren Neogloboquadrina pachyderma from the subpolar North Atlantic where wintertime mixing removes vertical gradients in temperature and salinity. This allows investigation of biologically controlled Mg/Ca intratest variability under natural conditions. We find that intratest Mg/Ca varies between <0.1 and 7 mmol/mol, even in winter specimens. High Mg/Ca bands occur at the outer edge of the laminae, indicating reduced Mg removal at the end of chamber formation. Our data thus provide new constraints on the timing of the formation of such bands and indicate that their presence is intrinsic to the chamber formation process. Additionally, all specimens are covered with an outer crust consisting of large euhedral crystals. The composition of the crust is similar to the low Mg/Ca bands in the laminar calcite in winter and summer specimens, indicating a tight biological control on crust formation and composition. Nevertheless, despite high intratest variability, the median Mg/Ca of summertime tests is higher than that of wintertime tests. This provides support for Mg/Ca paleothermometry, but to improve the accuracy of paleotemperature estimates biological effects on Mg incorporation need to be better accounted for Article in Journal/Newspaper Neogloboquadrina pachyderma North Atlantic Planktonic foraminifera Cardiff University: ORCA (Online Research @ Cardiff) Earth and Planetary Science Letters 451 177 184 |
institution |
Open Polar |
collection |
Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
description |
Many species of planktonic foraminifera show distinct banding in the intratest distribution of Mg/Ca. This heterogeneity appears biologically controlled and thus poses a challenge to Mg/Ca paleothermometry. The cause of this banding and its relation with chamber formation are poorly constrained and most of what we know about intratest Mg/Ca variability stems from culture studies of tropical, symbiont-bearing foraminifera. Here we present data on the non-spinose, symbiont-barren Neogloboquadrina pachyderma from the subpolar North Atlantic where wintertime mixing removes vertical gradients in temperature and salinity. This allows investigation of biologically controlled Mg/Ca intratest variability under natural conditions. We find that intratest Mg/Ca varies between <0.1 and 7 mmol/mol, even in winter specimens. High Mg/Ca bands occur at the outer edge of the laminae, indicating reduced Mg removal at the end of chamber formation. Our data thus provide new constraints on the timing of the formation of such bands and indicate that their presence is intrinsic to the chamber formation process. Additionally, all specimens are covered with an outer crust consisting of large euhedral crystals. The composition of the crust is similar to the low Mg/Ca bands in the laminar calcite in winter and summer specimens, indicating a tight biological control on crust formation and composition. Nevertheless, despite high intratest variability, the median Mg/Ca of summertime tests is higher than that of wintertime tests. This provides support for Mg/Ca paleothermometry, but to improve the accuracy of paleotemperature estimates biological effects on Mg incorporation need to be better accounted for |
format |
Article in Journal/Newspaper |
author |
Jonkers, Lukas Buse, Ben Brummer, Geert-Jan A. Hall, Ian Robert |
spellingShingle |
Jonkers, Lukas Buse, Ben Brummer, Geert-Jan A. Hall, Ian Robert Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma |
author_facet |
Jonkers, Lukas Buse, Ben Brummer, Geert-Jan A. Hall, Ian Robert |
author_sort |
Jonkers, Lukas |
title |
Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma |
title_short |
Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma |
title_full |
Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma |
title_fullStr |
Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma |
title_full_unstemmed |
Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma |
title_sort |
chamber formation leads to mg/ca banding in the planktonic foraminifer neogloboquadrina pachyderma |
publisher |
Elsevier |
publishDate |
2016 |
url |
https://orca.cardiff.ac.uk/id/eprint/93407/ https://doi.org/10.1016/j.epsl.2016.07.030 https://orca.cardiff.ac.uk/id/eprint/93407/1/Npac_EPMA_rev2_final.pdf |
genre |
Neogloboquadrina pachyderma North Atlantic Planktonic foraminifera |
genre_facet |
Neogloboquadrina pachyderma North Atlantic Planktonic foraminifera |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/93407/1/Npac_EPMA_rev2_final.pdf Jonkers, Lukas https://orca.cardiff.ac.uk/view/cardiffauthors/A642653Q.html orcid:0000-0002-0253-2639 orcid:0000-0002-0253-2639, Buse, Ben, Brummer, Geert-Jan A. and Hall, Ian Robert https://orca.cardiff.ac.uk/view/cardiffauthors/A002402L.html orcid:0000-0001-6960-1419 orcid:0000-0001-6960-1419 2016. Chamber formation leads to Mg/Ca banding in the planktonic foraminifer Neogloboquadrina pachyderma. Earth and Planetary Science Letters 451 , pp. 177-184. 10.1016/j.epsl.2016.07.030 https://doi.org/10.1016/j.epsl.2016.07.030 file https://orca.cardiff.ac.uk/id/eprint/93407/1/Npac_EPMA_rev2_final.pdf doi:10.1016/j.epsl.2016.07.030 |
op_rights |
cc_by_nc_nd |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1016/j.epsl.2016.07.030 |
container_title |
Earth and Planetary Science Letters |
container_volume |
451 |
container_start_page |
177 |
op_container_end_page |
184 |
_version_ |
1766072862185095168 |