| Title | A late Miocene-early Pliocene Antarctic deepwater record of repeated iron reduction events |
| Author | Hepp, D.A.; Mörz, T.; Hensen, C.; Frederichs, T.; Kasten, S.; Riedinger, N.; Hay, W.W. |
| Author Affil | Hepp, D.A., University of Bremen, Department of Geosciences, Bremen, Federal Republic of Germany. Other: University of Kiel, Federal Republic of Germany; Max-Planck-Institute for Marine Microbiology, Federal Republic of Germany; University of Colorado |
| Source | Marine Geology, 266(1-4), p.198-211, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 |
| Publication Date | Oct. 15, 2009 |
| Notes | In English. Includes appendices. 69 refs. GeoRef Acc. No: 296951. CRREL Acc. No: 64002035 |
| Index Terms | algae; climatic change; drift; geochemistry; glacial deposits; glacial geology; glacier flow; ice sheets; ocean environments; marine deposits; metals; paleoclimatology; paleoecology; sedimentation; sediments; ventilation; Antarctica--Antarctic Peninsula; Ocean Drilling Program--ODP Site 1095; Southern Ocean; Antarctic Peninsula; Antarctica; Cenozoic; clastic sediments; climate change; continental margin sedimentation; deep-water environment; deglaciation; diatoms; glacial environment; glaciomarine environment; ice movement; iron; Leg 178; lower Pliocene; magnetic susceptibility; marine environment; marine sediments; microfossils; Miocene; Neogene; Ocean Drilling Program; ODP Site 1095; ooze; organic compounds; paleo- oceanography; Plantae; Pliocene; productivity; reduction; Tertiary; upper Miocene |
| Abstract | In this study we present a late Miocene-early Pliocene record of sixty-four zones with prominent losses in the magnetic susceptibility signal, taken on a sediment drift (ODP Site 1095) on the Pacific continental rise of the West Antarctic Peninsula. The zones are comparable in shape and magnitude and occur commonly at glacial- to-interglacial transitions. High resolution records of organic matter, magnetic susceptibility and clay mineral composition from early Pliocene intervals demonstrate that neither dilution effects nor provenance changes of the sediments have caused the magnetic susceptibility losses. Instead, reductive dissolution of magnetite under suboxic conditions seems to be the most likely explanation. We propose that during the deglaciation exceptionally high organic fluxes in combination with weak bottom water currents and prominent sediment draping diatom ooze layers produced temporary suboxic conditions in the uppermost sediments. It is remarkable that synsedimentary suboxic conditions can be observed in one of the best ventilated open ocean regions of the World. |
| URL | http://hdl.handle.net/10.1016/j.margeo.2009.08.006 |
| Publication Type | journal article |
| Record ID | 87430 |