Ecological response to collapse of the biological pump following the mass extinction at the Cretaceous–Paleogene boundary
It is commonly accepted that the mass extinction associated with the Cretaceous–Paleogene (K–Pg) boundary (∼ 66 Ma) is related to the environmental effects of a large extraterrestrial impact. The biological and oceanographic consequences of the mass extinction are, however, still poorly understood....
Main Authors: | , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2017-02-01
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Series: | Biogeosciences |
Online Access: | http://www.biogeosciences.net/14/885/2017/bg-14-885-2017.pdf |
Summary: | It is commonly accepted that the mass extinction
associated with the Cretaceous–Paleogene (K–Pg) boundary (∼ 66 Ma) is related to the environmental effects of a large extraterrestrial
impact. The biological and oceanographic consequences of the mass extinction
are, however, still poorly understood. According to the <q>Living Ocean</q> model,
the biological crisis at the K–Pg boundary resulted in a long-term reduction
of export productivity in the early Paleocene. Here, we combine
organic-walled dinoflagellate cyst (dinocyst) and benthic foraminiferal
analyses to provide new insights into changes in the coupling of pelagic and
benthic ecosystems. To this end, we perform dinocyst and benthic
foraminiferal analyses on the recently discovered Tethyan K–Pg boundary
section at Okçular, Turkey, and compare the results with other K–Pg
boundary sites in the Tethys. The post-impact dominance of epibenthic
morphotypes and an increase of inferred heterotrophic dinocysts in the
early Paleocene at Okçular are consistent with published records from
other western Tethyan sites. Together, these records indicate that during
the early Paleocene more nutrients remained available for the Tethyan
planktonic community, whereas benthic communities were deprived of food.
Hence, in the post-impact phase the reduction of export productivity likely
resulted in enhanced recycling of nutrients in the upper part of the water
column, all along the western Tethyan margins. |
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ISSN: | 1726-4170 1726-4189 |