TY - JOUR
T1 - Middle Miocene Temperature and Productivity Evolution at a Northeast Atlantic Shelf Site (IODP U1318, Porcupine Basin)
T2 - Global and Regional Changes
AU - Sangiorgi, Francesca
AU - Quaijtaal, Willemijn
AU - Donders, Timme H.
AU - Schouten, Stefan
AU - Louwye, Stephen
N1 - Funding Information:
The samples for this study were provided by the Integrated Ocean Discovery Program. Walter Hale and Alex Wülbers kindly supported the sampling at the Bremen Core Repository. Ivo Vandemoortel is thanked for helping with isotope analyses. Anchelique Mets, Jort Ossebaar, Monique Verweij (NIOZ), and Sabine Van Cauwenberghe (UGent) are thanked for their technical assistance. We thank James Super and Matt Huber for sharing the biomarker data of ODP Site 982 and Sindia Sosdian for sharing CO data. We thank Stijn de Schepper and one anonymous reviewer for their comments, which greatly improved the manuscript. This work was supported by the Research Foundation‐Flanders (FWO) under project number G.0179.11N. SS thanks the Netherlands Earth System Science Center, funded by the Ministry of Education, Culture and Science (OCW). 2
Funding Information:
The samples for this study were provided by the Integrated Ocean Discovery Program. Walter Hale and Alex W?lbers kindly supported the sampling at the Bremen Core Repository. Ivo Vandemoortel is thanked for helping with isotope analyses. Anchelique Mets, Jort Ossebaar, Monique Verweij (NIOZ), and Sabine Van Cauwenberghe (UGent) are thanked for their technical assistance. We thank James Super and Matt Huber for sharing the biomarker data of ODP Site 982 and Sindia Sosdian for sharing CO2 data. We thank Stijn de Schepper and one anonymous reviewer for their comments, which greatly improved the manuscript. This work was supported by the Research Foundation-Flanders (FWO) under project number G.0179.11N. SS thanks the Netherlands Earth System Science Center, funded by the Ministry of Education, Culture and Science (OCW).
Publisher Copyright:
© 2021. The Authors.
PY - 2021/7
Y1 - 2021/7
N2 - We present a high-resolution multiproxy middle Miocene sea surface temperature (SST) and productivity (SSP) reconstruction of Integrated Ocean Drilling Program Site U1318, from the upper slope edge (∼400 m water depth) of the Porcupine Basin continental margin, eastern North Atlantic Ocean. Biomarker and dinoflagellate cyst proxies reveal warm and mostly stratified waters during the Miocene Climatic Optimum (MCO) that cooled ∼3°C across the Miocene Climate Transition (MCT). The organic biomarker (TEX86 and (Formula presented.)) paleothermometers document a series of 11 transient cooling events (CEs), superimposed on the long-term climate evolution. These CEs are associated with increases in cold-water dinocysts and correlate to global benthic δ18O shifts, including the Mi-2, Mi-3, and Mi-4 events. Most CEs are also associated with increases in primary productivity. A prolonged interval of high SSP between ∼13.8 and 13.6 Ma supports the idea that carbon production (and burial) in shallow areas represents a feedback mechanism contributing to long-term atmospheric CO2 decline and cooling during the MCT. SST comparison in three North Atlantic sites (Azores Site 608, Porcupine Basin Site U1318, and Rockall Plateau Site 982) reveals that MCO SSTs are much warmer at Site 608 than at the other two sites. The low-resolution SST record of Site 982 shows no decrease in temperature around the MCT. This may be linked to contemporaneous tectonic changes in the Tethys, Central American, and Arctic Seaways impacting local ocean circulation, superimposed on global drivers of climate change.
AB - We present a high-resolution multiproxy middle Miocene sea surface temperature (SST) and productivity (SSP) reconstruction of Integrated Ocean Drilling Program Site U1318, from the upper slope edge (∼400 m water depth) of the Porcupine Basin continental margin, eastern North Atlantic Ocean. Biomarker and dinoflagellate cyst proxies reveal warm and mostly stratified waters during the Miocene Climatic Optimum (MCO) that cooled ∼3°C across the Miocene Climate Transition (MCT). The organic biomarker (TEX86 and (Formula presented.)) paleothermometers document a series of 11 transient cooling events (CEs), superimposed on the long-term climate evolution. These CEs are associated with increases in cold-water dinocysts and correlate to global benthic δ18O shifts, including the Mi-2, Mi-3, and Mi-4 events. Most CEs are also associated with increases in primary productivity. A prolonged interval of high SSP between ∼13.8 and 13.6 Ma supports the idea that carbon production (and burial) in shallow areas represents a feedback mechanism contributing to long-term atmospheric CO2 decline and cooling during the MCT. SST comparison in three North Atlantic sites (Azores Site 608, Porcupine Basin Site U1318, and Rockall Plateau Site 982) reveals that MCO SSTs are much warmer at Site 608 than at the other two sites. The low-resolution SST record of Site 982 shows no decrease in temperature around the MCT. This may be linked to contemporaneous tectonic changes in the Tethys, Central American, and Arctic Seaways impacting local ocean circulation, superimposed on global drivers of climate change.
KW - dinoflagellate cysts
KW - middle Miocene
KW - North Atlantic
KW - sea surface productivity
KW - sea surface temperature
UR - http://www.scopus.com/inward/record.url?scp=85111595539&partnerID=8YFLogxK
U2 - 10.1029/2020PA004059
DO - 10.1029/2020PA004059
M3 - Article
AN - SCOPUS:85111595539
SN - 2572-4517
VL - 36
SP - 1
EP - 19
JO - Paleoceanography and Paleoclimatology
JF - Paleoceanography and Paleoclimatology
IS - 7
M1 - e2020PA004059
ER -