Reconstructing precipitation changes in northeastern Africa during the Quaternary by clay mineralogical and geochemical investigations of Nile deep-sea fan sediments Yulong Zhao a, b, * , Christophe Colin b , Zhifei Liu a , Martine Paterne c , Giuseppe Siani b , Xin Xie a a State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China b Laboratoire des Interactions et Dynamique des Environnements de Surface (IDES), UMR 8148 CNRS-Université de Paris-Sud 11, Orsay 91405, France c Laboratoire des Sciences du Climat et de l’Environnement (LSCE), UMR 8212 CEA-CNRS-UVSQ, Gif-sur-Yvette 91198, France article info Article history: Received 19 July 2012 Received in revised form 5 October 2012 Accepted 8 October 2012 Available online Keywords: Clay minerals Eastern Mediterranean Sea Nile deep-sea fan North Africa Precipitation African monsoon Saharan dust abstract Clay mineralogy combined with high-resolution element geochemistry of core MD90-9064, located in the distal part of the Nile deep-sea fan (Levantine Basin), have been investigated to reconstruct rainfall changes in northeastern Africa during the Quaternary and to determine possible climatic controls. Clay minerals of core MD90-964 are derived mainly from three sedimentary sources (the Sahara, Nile River and Egyptian wadis) and are characterized by contrasted mineralogical composition. Variations in illite content and logarithm ratios of Si/Al and K/Al permit the tracking of eolian input from Sahara to the Mediterranean Sea. It is suggested that precipitation changes in the Sahara are mainly dominated by glacialeinterglacial cycles. Such variations are owing to a shift of climatic conditions in the North Atlantic from a NAO-positive-like condition in glacial times to a NAO-negative-like condition in interglacial times. Fe content in the Levantine sediments is mostly derived from Fe-bearing heavy minerals brought by the Nile River. Therefore, variations of Fe/Al ratios can be used to establish precipitation changes in the Nile River basin. Long-term variation in precipitation in the Nile River basin is governed by precessional and eccentricity signals, implying that the African monsoon is the most significant controlling factor for precipitation changes in this region. Precipitation changes in the northeastern coasts of Africa are reconstructed using kaolinite contents provided by the Egyptian wadis. It is reported that precipitation in coastal northeastern Africa is mainly of the Mediterranean-climate type. Long-term variations in rainfall in this region are also affected by the NAO-like climatic variability and thus dominated by the glacial einterglacial cycles. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Annually, huge amounts of sediments are transported from the North African continent to the eastern Mediterranean Sea by permanent rivers and dust-bearing winds. Those sediments have well documented climate variability in North Africa, particularly due to changes of precipitation in the catchment of the Nile River and changes in aridity in the Sahara Desert (e.g. Foucault and Stanley, 1989; Wehausen and Brumsack, 1999, 2000; Foucault and Mélières, 2000; Calvert and Fontugne, 2001; Revel et al., 2010). Therefore, a great number of studies have been performed on terrigenous sediments from deep-sea cores (Cita et al., 1977; Maldonado and Stanley, 1981; Aksu et al., 1995; Brumsack and Wehausen, 1999; Wehausen and Brumsack, 1999, 2000; Foucault and Mélières, 2000; Calvert and Fontugne, 2001; Roussakis et al., 2004; Anastasakis, 2007; Ehrmann et al., 2007; Hamann et al., 2009), surface and core-top sediments (Venkatarathnam and Ryan, 1971; Maldonado and Stanley, 1981; Stanley et al., 1998; Sandler and Herut, 2000; Bayhan et al., 2001), borderland riverine or delta sediments (Weir et al., 1975; Stanley and Liyanage, 1986; Foucault and Stanley, 1989; Abu-Zeid and Stanley, 1990; Abdel Wahab and Stanley, 1991; Stanley and Wingerath, 1996; Stanley et al., 1997; Revel et al., 2010), and eolian dust samples (Chester et al., 1977; Tomadin et al., 1984; Wilke et al., 1984; Caquineau et al., 1998, 2002) in the eastern Mediterranean region in order to investigate the potential links between terrigenous sediments and climate changes in North Africa. These studies have greatly enriched our knowledge on (1) provenance and mineralogical compositions of terrigenous sediment in the eastern Mediterranean basin, (2) * Corresponding author. State Key Laboratory of Marine Geology, Tongji Univer- sity, Shanghai 200092, China. Fax: þ86 2165988808. E-mail addresses: yeoloon@gmail.com, yeoloon@tongji.edu.cn (Y. Zhao). Contents lists available at SciVerse ScienceDirect Quaternary Science Reviews journal homepage: www.elsevier.com/locate/quascirev 0277-3791/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.quascirev.2012.10.009 Quaternary Science Reviews 57 (2012) 58e70