Benthic foraminiferal assemblages across the Cretaceous Paleogene boundray of ODP Site 208-1262 on Walvis Ridge, eastern South Atlantic
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| Natura: | Dataset Open Access |
| Lingua: | en |
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PANGAEA
2007
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| _version_ | 1867169931971264512 |
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| author | Alegret, Laia Thomas, Ellen |
| author_facet | Alegret, Laia Thomas, Ellen |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Sediments recovered at ODP Site 1262 on Walvis Ridge (eastern South Atlantic Ocean, paleodepth ~2500–3000 m) offer an opportunity to look into the nature and cause(s) of the benthic foraminiferal turnover across the Cretaceous/Paleogene (K/Pg) boundary at abyssal depths at a location relatively remote from the location of the asteroid impact on the Yucatan peninsula. Late Maastrichtian assemblages were diverse and heterogeneous, reflecting oligo- to mesotrophic conditions at the sea floor. As at other locations, there was no significant extinction of benthic foraminiferal species at the K/Pg boundary, but the diversity and heterogeneity of the assemblages decreased precipitously. The percentage of infaunal buliminid taxa decreased rapidly, but the total percentage of infaunal taxa remained essentially unchanged. Benthic foraminiferal accumulation rates (BFAR) dropped at the boundary itself, and fluctuated strongly later in the Danian. After the K/Pg boundary, opportunistic taxa increased in relative abundance, and diversity and heterogeneity strongly fluctuated. There thus is no clear agreement between three proxies which have been used to indicate a high food supply to the sea floor: percentage buliminids, percentage infaunal taxa, and BFAR. This discrepancy might indicate that the food supply changed in character (e.g., type of food, temporal variability in flux), but did not show a long-term, large net change in total amount. The strong fluctuations in BFAR, heterogeneity and diversity indicate that environmental instability started at the K/Pg boundary, and persisted through planktic foraminiferal zones P* and P1a. In lower planktic foraminiferal zone P1b, agglutinated species of the genera Spiroplectammina and Clavulinoides, thought to be infaunal and indicative of increasing levels of food supply, increased in relative abundance while the relative abundance of buliminids remained low. Possibly, agglutinated taxa took over at least part of the infaunal niche in the Paleocene, as a result of the rise in the calcium carbonate compensation depth. Towards the upper part of the studied interval (lower planktic foraminiferal Subzone 1c), benthic foraminiferal assemblages stabilized, with heterogeneity almost back to Maastrichtian values, although diversity and BFAR did not fully recover. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_672083 |
| institution | PANGAEA |
| language | en |
| publishDate | 2007 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Benthic foraminiferal assemblages across the Cretaceous Paleogene boundray of ODP Site 208-1262 on Walvis Ridge, eastern South Atlantic Alegret, Laia Thomas, Ellen 208-1262; Alabamina creta; Alabamina sp.; Allomorphina velascoensis; Ammodiscus sp.; Angulogavelinella avnimelechi; Anomalinoides affinis; Anomalinoides ammonoides; Anomalinoides sp.; Anomalinoides spp.; Aragonia velascoensis; Arenobulimina truncata; Astacolus spp.; Bolivina cf. huneri; Bolivinoides decoratus; Bolivinoides delicatulus; Buchnerina sp.; Bulimina cf. alazanensis; Bulimina kugleri; Bulimina midwayensis; Bulimina paleocenica; Bulimina spp.; Bulimina trinitatensis; Bulimina velascoensis; Buliminella beaumonti; Buliminella sp.; Caudammina ovula; Cibicidoides cf. dayi; Cibicidoides cf. naranjoensis; Cibicidoides howelli; Cibicidoides hyphalus; Cibicidoides pseudoacutus; Cibicidoides sp.; Cibicidoides velascoensis; Clavulinoides amorpha; Clavulinoides sp.; COMPCORE; Composite Core; Coryphostoma spp.; Counting >63 µm fraction; DEPTH, sediment/rock; Dorothia bulletta; Dorothia spp.; Dorothia trochoides; DSDP/ODP/IODP sample designation; Ellipsodimorphina spp.; Eouvigerina sp.; Fishers alpha index of diversity; Fissurina spp.; Foraminifera, benthic; Foraminifera, benthic, epifaunal; Foraminifera, benthic, infaunal; Frondicularia sp.; Fursenkoina sp.; Fursenkoina tegulata; Gaudryina pyramidata; Gaudryina spp.; Glandulina sp.; Globobulimina sp.; Globorotalites sp.; Globulina prisca; Globulina spp.; Glomospira sp.; Glomospirella grzybowskii; Guttulina sp.; Gyroidinoides beisseli; Gyroidinoides depressus; Gyroidinoides girardana; Gyroidinoides globosus; Gyroidinoides quadratus; Gyroidinoides sp.; Hemirobulina sp.; Heronallenia lingulata; Hyperammina sp.; Joides Resolution; Laevidentalina spp.; Lagena spp.; Leg208; Lenticulina spp.; Lenticulina velascoensis; Lingulina sp.; Marssonella indentata; Marssonella oxycona; Marssonella sp.; Neoflabellina sp.; Nonionella cretacea; Nonionella sp.; Nuttallides spp.; Nuttallides truempyi; Nuttallinella florealis; Nuttallinella spp.; Ocean Drilling Program; ODP; Oolina spp.; Oridorsalis plummerae; Oridorsalis umbonatus; Osangularia cordieriana; Osangularia spp.; Osangularia velascoensis; Paliolatella sp.; Paralabamina cf. hillebrandti; Paralabamina hillebrandti; Paralabamina lunata; Paratrochamminoides sp.; Pleurostomella sp.; Polymorphinella sp.; Praebulimina reussi; Praebulimina sp.; Pullenia coryelli; Pullenia cretacea; Pullenia jarvisi; Pyramidina rudita; Pyrulina spp.; Pyrulinoides sp.; Quadratobuliminella pyramidalis; Quadratobuliminella sp.; Quadrimorphina allomorphinoides; Quadrimorphina cf. allomorphinoides; Quadrimorphina spp.; Quadrimorphina varsoviensis; Recurvoides sp.; Reophax sp.; Repmanina charoides; Reussella szajnochae; Rhizammina sp.; Rotamorphina sp.; Rzehakina sp.; Saccammina sp.; Sample code/label; Saracenaria sp.; Scheibnerova sp.; Seabrookia cretacea; Shannon Diversity Index; Siphogenerinoides sp.; Spirillina sp.; Spiroplectammina cf. dentata; Spiroplectammina cf. israelskyi; Spiroplectammina cf. laevis; Spiroplectammina spectabilis; Spiroplectammina spp.; Stainforthia sp.; Stensioeina beccariiformis; Stilostomella spp.; Stilostomella subspinosa; Tappanina selmensis; Tappanina spp.; Trochamminoides sp.; Vaginulina trilobata; Valvalabamina lenticula; Valvulineria sp.; Vulvulina sp.; Walvis Ridge, Southeast Atlantic Ocean Sediments recovered at ODP Site 1262 on Walvis Ridge (eastern South Atlantic Ocean, paleodepth ~2500–3000 m) offer an opportunity to look into the nature and cause(s) of the benthic foraminiferal turnover across the Cretaceous/Paleogene (K/Pg) boundary at abyssal depths at a location relatively remote from the location of the asteroid impact on the Yucatan peninsula. Late Maastrichtian assemblages were diverse and heterogeneous, reflecting oligo- to mesotrophic conditions at the sea floor. As at other locations, there was no significant extinction of benthic foraminiferal species at the K/Pg boundary, but the diversity and heterogeneity of the assemblages decreased precipitously. The percentage of infaunal buliminid taxa decreased rapidly, but the total percentage of infaunal taxa remained essentially unchanged. Benthic foraminiferal accumulation rates (BFAR) dropped at the boundary itself, and fluctuated strongly later in the Danian. After the K/Pg boundary, opportunistic taxa increased in relative abundance, and diversity and heterogeneity strongly fluctuated. There thus is no clear agreement between three proxies which have been used to indicate a high food supply to the sea floor: percentage buliminids, percentage infaunal taxa, and BFAR. This discrepancy might indicate that the food supply changed in character (e.g., type of food, temporal variability in flux), but did not show a long-term, large net change in total amount. The strong fluctuations in BFAR, heterogeneity and diversity indicate that environmental instability started at the K/Pg boundary, and persisted through planktic foraminiferal zones P* and P1a. In lower planktic foraminiferal zone P1b, agglutinated species of the genera Spiroplectammina and Clavulinoides, thought to be infaunal and indicative of increasing levels of food supply, increased in relative abundance while the relative abundance of buliminids remained low. Possibly, agglutinated taxa took over at least part of the infaunal niche in the Paleocene, as a result of the rise in the calcium carbonate compensation depth. Towards the upper part of the studied interval (lower planktic foraminiferal Subzone 1c), benthic foraminiferal assemblages stabilized, with heterogeneity almost back to Maastrichtian values, although diversity and BFAR did not fully recover. |
| title | Benthic foraminiferal assemblages across the Cretaceous Paleogene boundray of ODP Site 208-1262 on Walvis Ridge, eastern South Atlantic |
| topic | 208-1262; Alabamina creta; Alabamina sp.; Allomorphina velascoensis; Ammodiscus sp.; Angulogavelinella avnimelechi; Anomalinoides affinis; Anomalinoides ammonoides; Anomalinoides sp.; Anomalinoides spp.; Aragonia velascoensis; Arenobulimina truncata; Astacolus spp.; Bolivina cf. huneri; Bolivinoides decoratus; Bolivinoides delicatulus; Buchnerina sp.; Bulimina cf. alazanensis; Bulimina kugleri; Bulimina midwayensis; Bulimina paleocenica; Bulimina spp.; Bulimina trinitatensis; Bulimina velascoensis; Buliminella beaumonti; Buliminella sp.; Caudammina ovula; Cibicidoides cf. dayi; Cibicidoides cf. naranjoensis; Cibicidoides howelli; Cibicidoides hyphalus; Cibicidoides pseudoacutus; Cibicidoides sp.; Cibicidoides velascoensis; Clavulinoides amorpha; Clavulinoides sp.; COMPCORE; Composite Core; Coryphostoma spp.; Counting >63 µm fraction; DEPTH, sediment/rock; Dorothia bulletta; Dorothia spp.; Dorothia trochoides; DSDP/ODP/IODP sample designation; Ellipsodimorphina spp.; Eouvigerina sp.; Fishers alpha index of diversity; Fissurina spp.; Foraminifera, benthic; Foraminifera, benthic, epifaunal; Foraminifera, benthic, infaunal; Frondicularia sp.; Fursenkoina sp.; Fursenkoina tegulata; Gaudryina pyramidata; Gaudryina spp.; Glandulina sp.; Globobulimina sp.; Globorotalites sp.; Globulina prisca; Globulina spp.; Glomospira sp.; Glomospirella grzybowskii; Guttulina sp.; Gyroidinoides beisseli; Gyroidinoides depressus; Gyroidinoides girardana; Gyroidinoides globosus; Gyroidinoides quadratus; Gyroidinoides sp.; Hemirobulina sp.; Heronallenia lingulata; Hyperammina sp.; Joides Resolution; Laevidentalina spp.; Lagena spp.; Leg208; Lenticulina spp.; Lenticulina velascoensis; Lingulina sp.; Marssonella indentata; Marssonella oxycona; Marssonella sp.; Neoflabellina sp.; Nonionella cretacea; Nonionella sp.; Nuttallides spp.; Nuttallides truempyi; Nuttallinella florealis; Nuttallinella spp.; Ocean Drilling Program; ODP; Oolina spp.; Oridorsalis plummerae; Oridorsalis umbonatus; Osangularia cordieriana; Osangularia spp.; Osangularia velascoensis; Paliolatella sp.; Paralabamina cf. hillebrandti; Paralabamina hillebrandti; Paralabamina lunata; Paratrochamminoides sp.; Pleurostomella sp.; Polymorphinella sp.; Praebulimina reussi; Praebulimina sp.; Pullenia coryelli; Pullenia cretacea; Pullenia jarvisi; Pyramidina rudita; Pyrulina spp.; Pyrulinoides sp.; Quadratobuliminella pyramidalis; Quadratobuliminella sp.; Quadrimorphina allomorphinoides; Quadrimorphina cf. allomorphinoides; Quadrimorphina spp.; Quadrimorphina varsoviensis; Recurvoides sp.; Reophax sp.; Repmanina charoides; Reussella szajnochae; Rhizammina sp.; Rotamorphina sp.; Rzehakina sp.; Saccammina sp.; Sample code/label; Saracenaria sp.; Scheibnerova sp.; Seabrookia cretacea; Shannon Diversity Index; Siphogenerinoides sp.; Spirillina sp.; Spiroplectammina cf. dentata; Spiroplectammina cf. israelskyi; Spiroplectammina cf. laevis; Spiroplectammina spectabilis; Spiroplectammina spp.; Stainforthia sp.; Stensioeina beccariiformis; Stilostomella spp.; Stilostomella subspinosa; Tappanina selmensis; Tappanina spp.; Trochamminoides sp.; Vaginulina trilobata; Valvalabamina lenticula; Valvulineria sp.; Vulvulina sp.; Walvis Ridge, Southeast Atlantic Ocean |
| url | https://doi.org/10.1594/PANGAEA.672083 |