Tracking climate variability in the western Mediterranean during the late Holocene; a multiproxy approach

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doi: 10.5194/cpd-7-635-2011
Author(s): Nieto-Moreno, Vanesa; Mart©Ưnez-Ruiz, Francisca; Giralt, Santiago; Jim©♭nez-Espejo, Francisco Jos©♭; Gallego-Torres, David; Rodrigo-G©Łmiz, M.; Garc©Ưa-Orellana, Jordi; Ortega-Huertas, Miguel; de Lange, G. J.
Author Affiliation(s): Primary:
Universidad de Granada, Instituto Andaluz de Ciencias de la Tierra, Granada, Spain
Other:
CSIC, Institut de Ciencies de la Terra Jaume Almera, Spain
Universitat Aut©ønoma de Barcelona, Spain
Utrecht University, Netherlands
Volume Title: Climate of the Past
Source: Climate of the Past, 7(4), p.1395-1414. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1814-9324
Note: In English. Part of special issue no. 35, Characterization of climatic variability in the Iberian Peninsula during the last centuries, edited by DomŁnguez-Castro, F., et al., http://www.clim-past.net/special_issue35.html; published in Climate of the Past Discussion: 21 February 2011, http://www.clim-past-discuss.net/7/635/2011/cpd-7-635-2011.html; accessed in Feb., 2012. 125 refs.; illus., incl. 2 tables, sketch map
Summary: Climate variability in the western Mediterranean is reconstructed for the last 4000 yr using marine sediments recovered in the west Algerian-Balearic Basin, near the Alboran Basin. Fluctuations in chemical and mineralogical sediment composition as well as grain size distribution are linked to fluvial-eolian oscillations, changes in redox conditions and paleocurrent intensity. Multivariate analyses allowed us to characterize three main groups of geochemical and mineralogical proxies determining the sedimentary record of this region. These three statistical groups were applied to reconstruct paleoclimate conditions at high resolution during the Late Holocene. An increase in riverine input (fluvial-derived elements--Rb/Al, Ba/Al, REE/Al, Si/Al, Ti/Al, Mg/Al and K/Al ratios), and a decrease in Saharan eolian input (Zr/Al ratio) depict the Roman Humid Period and the Little Ice Age, while drier environmental conditions are recognized during the Late Bronze Age-Iron Age, the Dark Ages and the Medieval Climate Anomaly. Additionally, faster bottom currents and more energetic hydrodynamic conditions for the former periods are evidenced by enhanced sortable silt (10-63 ℗æm) and quartz content, and by better oxygenated bottom waters--as reflected by decreasing redox-sensitive elements (V/Al, Cr/Al, Ni/Al and Zn/Al ratios). In contrast, opposite paleoceanographic conditions are distinguished during the latter periods, i.e. the Late Bronze Age-Iron Age, the Dark Ages and the Medieval Climate Anomaly. Although no Ba excess was registered, other paleoproductivity indicators (total organic carbon content, Br/Al ratio, and organometallic ligands such as U and Cu) display the highest values during the Roman Humid Period, and together with increasing preservation of organic matter, this period exhibits by far the most intense productivity of the last 4000 yr. Fluctuations in detrital input into the basin as the main process managing deposition, reflected by the first eigenvector defined by the Principal Component Analyses, point to solar irradiance and the North Atlantic Oscillation variability as the main driving mechanisms behind natural climate variability over decadal to centennial time-scales for the last 4000 yr.
Year of Publication: 2011
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Alboran Sea; Alkaline earth metals; Balearic Basin; Barium; Bronze Age; C-14; Carbon; Cenozoic; Climate change; Foraminifera; Geochemical controls; Geostatistics; Globigerina; Globigerina bulloides; Globigerinacea; Globigerinidae; Holocene; Invertebrata; Iron Age; Isotopes; Leg 161; Little Ice Age; Mediterranean Sea; Mediterranean region; Metals; Microfossils; Middle Ages; Multivariate analysis; Neoglacial; North Atlantic Oscillation; ODP Site 976; Ocean Drilling Program; Organic compounds; Paleo-oceanography; Paleoclimatology; Paleoenvironment; Protista; Quaternary; Radioactive isotopes; Rotaliina; Statistical analysis; Total organic carbon; Upper Holocene; West Mediterranean
Coordinates: N340000 N390000 E0010000 W0053000
Record ID: 2012049239
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany