Middle Miocene Temperature and Productivity Evolution at a Northeast Atlantic Shelf Site (IODP U1318, Porcupine Basin): Global and Regional Changes
نویسندگان
چکیده
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) Porcupine Basin continental margin, eastern North Atlantic Ocean. Biomarker dinoflagellate cyst proxies reveal warm mostly stratified waters during Climatic Optimum (MCO) that cooled ∼3°C across Climate Transition (MCT). The organic biomarker (TEX86 ) paleothermometers document series 11 transient cooling events (CEs), superimposed on long-term climate evolution. These CEs are associated with increases in cold-water dinocysts correlate to global benthic δ18O shifts, including Mi-2, Mi-3, Mi-4 events. Most also primary productivity. A prolonged interval high SSP between ∼13.8 13.6 Ma supports idea carbon production (and burial) shallow areas represents feedback mechanism contributing atmospheric CO2 decline MCT. SST comparison three sites (Azores 608, Rockall Plateau 982) reveals MCO SSTs much warmer at 608 than other two sites. low-resolution record 982 shows no decrease around This may be linked contemporaneous tectonic changes Tethys, Central American, Arctic Seaways impacting local ocean circulation, drivers change.
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ژورنال
عنوان ژورنال: Paleoceanography and paleoclimatology
سال: 2021
ISSN: ['2572-4517', '2572-4525']
DOI: https://doi.org/10.1029/2020pa004059