Venuti, Alessadra and Florindo, Fabio and Caburlotto, Andrea and Hounslow, Mark W. and Hillenbrand, Claus Dieter and Strada, Eleonora and Talarico, Franco M. and Cavallo, Andrea (2011) Late Quaternary sediments from deep-sea sediment drifts on the Antarctic Peninsula Pacific margin:climatic control on provenance of minerals. Journal of Geophysical Research: Solid Earth, 116 (B6).
 We present results of detailed paleomagnetic investigations on deep-sea cores from sediment drifts located along the Pacific continental margin of the Antarctic Peninsula. High-resolution magnetic measurements on u channel samples provide detailed age models for three cores collected from drift 7, which document an age of 122 ka for the oldest sediments recovered near the drift crest at site SED-07 and a high sedimentation rate (11 cm/kyr) at site SED-12 located close to the Alexander Channel system. Low- and high-temperature magnetic measurements in conjunction with microscopic and mineralogic observations from drifts 4, 5 and 7 indicate that pseudosingle-domain detrital titanomagnetite (partially oxidized and with limited Ti substitution) is the dominant magnetic mineral in the drift sediments. The titanomagnetite occurs in two magnetic forms: (1) a low-coercivity form similar to laboratory-synthesized titanomagnetite and (2) a high-coercivity form (Bcr > 60 mT). These two forms vary in amount and stratigraphic distribution across the drifts. We did not find evidence for diagenetic magnetic iron sulfides as has been previously suggested for these drift deposits. The observed change of magnetic mineralogy in sediments deposited during Heinrich events on drift 7 appears to be related to warming periods, which temporarily modified the normal glacial transport pathways of glaciogenic detritus to and along the continental rise and thus resulted in deposition of sediments with a different provenance. Understanding this sediment provenance delivery signature at a wider spatial scale should provide information about ice sheet dynamics in West Antarctica over the last ∼100 kyr.
|Item Type: ||Article|
|Journal or Publication Title: ||Journal of Geophysical Research: Solid Earth|
|Additional Information: ||Copyright 2011 by the American Geophysical Union.|
|Uncontrolled Keywords: ||Antarctic Peninsula ; Pacific margin ; sediment drift ; late Pleistocene ; mineral magnetism ; relative palaeointensity|
|Departments: ||Faculty of Science and Technology > Lancaster Environment Centre|
|ID Code: ||49346|
|Deposited By: ||ep_importer_pure|
|Deposited On: ||28 Jul 2011 13:45|
|Last Modified: ||21 Feb 2017 02:03|
|Identification Number: |
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