Nile River sediment fluctuations over the past 7000 yr and their key role in sapropel development

Abstract

Research Article| January 01, 2002 Nile River sediment fluctuations over the past 7000 yr and their key role in sapropel development Michael D. Krom; Michael D. Krom 1School of Earth Sciences, University of Leeds, Leeds LS2 9JT, UK Search for other works by this author on: GSW Google Scholar J. Daniel Stanley; J. Daniel Stanley 2Deltas-Global Change Program, Smithsonian Institution, Washington, D.C. 20560, USA Search for other works by this author on: GSW Google Scholar Robert A. Cliff; Robert A. Cliff 3School of Earth Sciences, University of Leeds, Leeds LS2 9JT, UK Search for other works by this author on: GSW Google Scholar Jamie C. Woodward Jamie C. Woodward 4School of Geography, University of Leeds, Leeds LS2 9JT, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Michael D. Krom 1School of Earth Sciences, University of Leeds, Leeds LS2 9JT, UK J. Daniel Stanley 2Deltas-Global Change Program, Smithsonian Institution, Washington, D.C. 20560, USA Robert A. Cliff 3School of Earth Sciences, University of Leeds, Leeds LS2 9JT, UK Jamie C. Woodward 4School of Geography, University of Leeds, Leeds LS2 9JT, UK Publisher: Geological Society of America Received: 05 Jun 2001 Revision Received: 28 Sep 2001 Accepted: 01 Oct 2001 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (1): 71–74. https://doi.org/10.1130/0091-7613(2002)030<0071:NRSFOT>2.0.CO;2 Article history Received: 05 Jun 2001 Revision Received: 28 Sep 2001 Accepted: 01 Oct 2001 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Michael D. Krom, J. Daniel Stanley, Robert A. Cliff, Jamie C. Woodward; Nile River sediment fluctuations over the past 7000 yr and their key role in sapropel development. Geology 2002;; 30 (1): 71–74. doi: https://doi.org/10.1130/0091-7613(2002)030<0071:NRSFOT>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The provenance pattern of Nile River sediments can be used as a proxy for paleoclimatic changes in East Africa. The 87Sr/86Sr ratios are particularly appropriate for such provenance investigations, because the White Nile drains predominantly crystalline basement rocks, whereas the Blue Nile and Atbara flow off the Ethiopian Highlands, which consist of Tertiary volcanic rocks. A high-resolution profile of 87Sr/86Sr and Ti/Al ratios from a well-dated core in the Nile Delta shows a close correspondence with known changes in Nile flow over the past 7000 yr. At times of higher river flow there was markedly decreased input of Blue Nile–derived and total sediment. This change was caused by northward movement of the Inter Tropical Convergence Zone, resulting in increased vegetative cover in the Ethiopian Highlands due to higher rainfall and a longer wet season. This inverse relationship between Nile River flow and sediment flux may have had important implications in the development of agricultural technology in ancient Egypt. The marked minimum in 87Sr/86Sr at 4200–4500 yr B.P. is coincident with the end of the Old Kingdom in Egypt and provides independent evidence that demise of the Old Kingdom might have been associated with an extended period of catastrophic low floods. During the Quaternary and late Neogene, there was periodic deposition of organic-rich sediments (sapropels) in the eastern Mediterranean that represent important indicators of major environmental change. Evidence from the Ti/Al ratio suggests that the pattern of erosion and sediment supply from the Nile catchment observed in this study also occurred throughout much of the Neogene and Quaternary. The reduced inputs of Blue Nile sediment during times of sapropel formation contributed to the increased primary productivity by reducing the amount of phosphate removed on particles and to the observed change to N limitation in the eastern Mediterranean, which are important characteristics of sapropel deposition. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.