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J Paleolimnol (2009) 42:587609 DOI 10.1007/s10933-009-9307-x
ORIGINAL PAPER
First lacustrine varve chronologies from Mexico: impact of droughts, ENSO and human activity since AD 1840 as recorded in maar sediments from Valle de Santiago
Ulrike Kienel Sabine Wulf Bowen Roger Byrne Jungjae Park Harald Bhnel Peter Dulski James F. Luhr Lee Siebert Gerald H. Haug Jrg F. W. Negendank
Received: 19 March 2008 / Accepted: 1 January 2009 / Published online: 24 February 2009 The Author(s) 2009. This article is published with open access at Springerlink.com
Abstract We present varve chronologies for sediments from two maar lakes in the Valle de Santiago region (Central Mexico): Hoya La Alberca (AD 1852 1973) and Hoya Rincn de Parangueo (AD 18391943). These are the rst varve chronologies for Mexican lakes. The varved sections were anchored with tephras from Colima (1913) and Paricutn (1943/1944) and
210Pb ages. We compare the sequences using the thickness of seasonal laminae and element counts (Al, Si, S, Cl, K, Ti, Mn, Fe, and Sr) determined by micro X-ray uorescence spectrometry. The formation
of the varve sublaminae is attributed to the strongly seasonal climate regime. Limited rainfall and high evaporation rates in winter and spring induce precipitation of carbonates (high Ca, Sr) enriched in 13C and
18O, whereas rainfall in summer increases organic and clastic input (plagioclase, quartz) with high counts of lithogenic elements (K, Al, Ti, and Si). Eolian input of Ti occurs also in the dry season. Moving correlations (5-yr windows) of the Ca and Ti counts show similar development in both sequences until the 1930s. Positive correlations indicate mixing of allochthonous Ti and autochthonous Ca, while negative correlations indicate their separation in sublaminae. Negative excursions in the correlations correspond with historic and reconstructed droughts, El Nio events, and
This paper is dedicated to our colleague and friend Jim Luhr, Director of the Smithsonians Global Volcanism Program and acionado of Mexican volcanoes, who unexpectedly passed away on 1 January 2007.
U. Kienel (&) S. W. Bowen P. Dulski
J. F. W. NegendankHelmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Section. 3.3 Climate Dynamics and Sediments, Telegrafenberg Haus C, 14473 Potsdam, Germanye-mail: [email protected]
S. W. BowenInstitute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, J.J. Pickle Research Campus, Bldg. 196,...