Influence of orbital forcing and sea level changes on sedimentation patterns in the Timor Sea during the last 260 ka

Eva Moreno (1) , Franck Bassinot (2, 3) , François Baudin (4) , Marie-Thérèse Vénec-Peyré (1)

1 CR2P - Centre de Recherche en Paléontologie - Paris
2 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
3 PALEOCEAN - Paléocéanographie
4 Sorbonne Université - Département de Géologie Sédimentaire

[1] A multiproxy study of core MD98-2166 makes it possible to investigate the influence of orbital forcing and sea level changes on Timor Sea sedimentation during the last 260 ka. Spectral analysis reveals a strong imprint of obliquity in all proxies. This is particularly puzzling for the CaCO 3 and total organic carbon (TOC) records since recent data obtained on nearby core MD01-2378, collected at a shallower water depth, showed a concentration of spectral power in the eccentricity and precession bands. Our results suggest that while sedimentary record in shallower core MD01-2378 shows a clear low-latitude response, that of core MD98-2166 reflects a stronger influence of high-latitude forcing through deepwater changes. In addition, Rock-Eval analyses show that part of the organic carbon could be of terrestrial origin, especially during glacial periods. This suggests that glacial/interglacial TOC fluctuations not only reflect changes of marine productivity and/or preservation at the seafloor but also reflect enhanced input of terrestrial material during periods of low sea level.

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

Eva Moreno, Franck Bassinot, François Baudin, Marie-Thérèse Vénec-Peyré. Influence of orbital forcing and sea level changes on sedimentation patterns in the Timor Sea during the last 260 ka. Paleoceanography, 2008, 23 (1), pp.n/a-n/a. ⟨10.1029/2007PA001423⟩. ⟨hal-02921445⟩