| Title | Southern Ocean frontal system changes precede Antarctic ice sheet growth during the middle Miocene |
| Author | Kuhnert, H.; Bickert, T.; Paulsen, H. |
| Author Affil | Kuhnert, H., Universität Bremen, Center for Marine Environmental Sciences, Bremen, Federal Republic of Germany |
| Source | Earth and Planetary Science Letters, 284(3-4), p.630-638. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012- 821X |
| Publication Date | July 15, 2009 |
| Notes | In English. Supplementary data available in online version. 66 refs. GeoRef Acc. No: 300013. CRREL Acc. No: 64004649 |
| Index Terms | climatic change; glaciation; isotopes; metals; oxygen; paleoclimatology; Antarctica-- Antarctic ice sheet; Ocean Drilling Program-- ODP Site 1092; Atlantic Ocean--South Atlantic; Southern Ocean; alkaline earth metals; Antarctic Circumpolar Current; Antarctic ice sheet; Antarctica; Atlantic Ocean; calcium; Cenozoic; climate change; Foraminifera; fresh water; Invertebrata; isotope ratios; Leg 177; magnesium; Mg/Ca; microfossils; middle Miocene; Miocene; Neogene; O-18/O-16; Ocean Drilling Program; ODP Site 1092; paleo-oceanography; paleotemperature; Protista; sea water; sea- surface temperature; South Atlantic; stable isotopes; Tertiary |
| Abstract | The middle Miocene climate approximately 14 Ma ago was characterized by the glaciation of Antarctica, deep-ocean cooling and variations in the global carbon cycle. Although the Southern Ocean underwent significant oceanographic changes, there is limited information on their spatial extent and timing. However, such knowledge is crucial for understanding the role of the Southern Ocean and the Antarctic Circumpolar Current (ACC) for Antarctic glaciation and the coupling between the ocean and continental climate. We have reconstructed surface temperatures and seawater oxygen isotopes at Ocean Drilling Program (ODP) Site 1092 in the Polar Frontal Zone of the Atlantic sector of the Southern Ocean from foraminiferal oxygen isotopes (delta 18O) and magnesium to calcium ratios (Mg/Ca). Sea surface cooling by approx. 4 °C and freshening indicated by the approx. 1 ppt reduction of seawater delta 18O (delta 18Osw) at 14.2 Ma precede the major step in Antarctic ice sheet growth at 13.8-13.9 Ma. (mod. journ. abst.) |
| URL | http://hdl.handle.net/10.1016/j.epsl.2009.05.030 |
| Publication Type | journal article |
| Record ID | 88402 |