(Table S1) Results of Nd measurements on uncleaned, mixed-planktonic foraminiera, bulk sediment leachates and detrital material
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| Natura: | Dataset Open Access |
| Lingua: | en |
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PANGAEA
2017
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| _version_ | 1867169118453497856 |
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| author | Dausmann, Veit Frank, Martin Gutjahr, Marcus Rickli, Jörg Dominik |
| author_facet | Dausmann, Veit Frank, Martin Gutjahr, Marcus Rickli, Jörg Dominik |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Combined seawater radiogenic hafnium (Hf) and neodymium (Nd) isotope compositions were extracted from bulk sediment leachates and foraminifera of Site 1088, ODP Leg 177, 2082 m water depth on the Agulhas Ridge. The new data provide a continuous reconstruction of long and short-term changes in ocean circulation and continental weathering inputs since the Mid-Miocene. Due to its intermediate water depth the sediments of this core sensitively recorded changes in admixture of North Atlantic Deep Water (NADW) to the Antarctic Circumpolar Current (ACC) as a function of the strength of the Atlantic Meridional Overturning Circulation (AMOC). Nd isotope compositions (epsilon-Nd) range from -7 to -11 with glacial values generally 1 to 3 units more radiogenic than during the interglacials of the Quaternary. The data reveal episodes of significantly increased AMOC strength during late Miocene and Pliocene warm periods whereas peak radiogenic epsilon-Nd values mark a strongly diminished AMOC during the major intensification of Northern Hemisphere Glaciation near 2.8 Ma and in the Pleistocene after 1.5 Ma. In contrast, the Hf isotope compositions (epsilon-Hf) show an essentially continuous evolution from highly radiogenic values of up to +11 during the Miocene to less radiogenic present day values (+2 to +4) during the late Quaternary. The data document a long-term transition in dominant weathering inputs, where inputs from the South America are replaced by those from Southern Africa. Moreover, radiogenic peaks provide evidence for the supply of radiogenic Hf originating from Patagonian rocks to the Atlantic sector of the Southern Ocean via dust inputs. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_871943 |
| institution | PANGAEA |
| language | en |
| publishDate | 2017 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table S1) Results of Nd measurements on uncleaned, mixed-planktonic foraminiera, bulk sediment leachates and detrital material Dausmann, Veit Frank, Martin Gutjahr, Marcus Rickli, Jörg Dominik 177-1088B; AGE; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Hafnium-176/Hafnium-177 ratio; Hafnium-176/Hafnium-177 ratio, standard deviation; Joides Resolution; Leg177; Method comment; Neodymium-143/Neodymium-144 ratio; Neodymium-143/Neodymium-144 ratio, standard deviation; Northern Component Water; Ocean Drilling Program; ODP; Sample code/label; South Atlantic Ocean; ε-Hafnium; ε-Hafnium, standard deviation; ε-Neodymium; ε-Neodymium, standard deviation Combined seawater radiogenic hafnium (Hf) and neodymium (Nd) isotope compositions were extracted from bulk sediment leachates and foraminifera of Site 1088, ODP Leg 177, 2082 m water depth on the Agulhas Ridge. The new data provide a continuous reconstruction of long and short-term changes in ocean circulation and continental weathering inputs since the Mid-Miocene. Due to its intermediate water depth the sediments of this core sensitively recorded changes in admixture of North Atlantic Deep Water (NADW) to the Antarctic Circumpolar Current (ACC) as a function of the strength of the Atlantic Meridional Overturning Circulation (AMOC). Nd isotope compositions (epsilon-Nd) range from -7 to -11 with glacial values generally 1 to 3 units more radiogenic than during the interglacials of the Quaternary. The data reveal episodes of significantly increased AMOC strength during late Miocene and Pliocene warm periods whereas peak radiogenic epsilon-Nd values mark a strongly diminished AMOC during the major intensification of Northern Hemisphere Glaciation near 2.8 Ma and in the Pleistocene after 1.5 Ma. In contrast, the Hf isotope compositions (epsilon-Hf) show an essentially continuous evolution from highly radiogenic values of up to +11 during the Miocene to less radiogenic present day values (+2 to +4) during the late Quaternary. The data document a long-term transition in dominant weathering inputs, where inputs from the South America are replaced by those from Southern Africa. Moreover, radiogenic peaks provide evidence for the supply of radiogenic Hf originating from Patagonian rocks to the Atlantic sector of the Southern Ocean via dust inputs. |
| title | (Table S1) Results of Nd measurements on uncleaned, mixed-planktonic foraminiera, bulk sediment leachates and detrital material |
| topic | 177-1088B; AGE; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Hafnium-176/Hafnium-177 ratio; Hafnium-176/Hafnium-177 ratio, standard deviation; Joides Resolution; Leg177; Method comment; Neodymium-143/Neodymium-144 ratio; Neodymium-143/Neodymium-144 ratio, standard deviation; Northern Component Water; Ocean Drilling Program; ODP; Sample code/label; South Atlantic Ocean; ε-Hafnium; ε-Hafnium, standard deviation; ε-Neodymium; ε-Neodymium, standard deviation |
| url | https://doi.org/10.1594/PANGAEA.871943 |