Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/102002
Title: The paleohydrological evolution of Lago Chungará Andean Altiplano, northern Chile) during the Lateglacial and early Holocene using oxigen isotopes in diatom silica
Author: Hernández Hernández, Armand
Bao Casal, Roberto
Giralt Romeu, Santiago
Leng, Melanie J.
Barker, Philip A
Sáez, Alberto
Pueyo Mur, Juan José
Moreno, Ana
Valero Garcés, Blas Lorenzo
Sloane, H.J.
Keywords: Quaternari
Sediments lacustres
Paleoclimatologia
Sílice
Isòtops
Quaternary
Lake sediments
Paleoclimatology
Silica
Isotopes
Issue Date: May-2008
Publisher: John Wiley & Sons
Abstract: Oxygen isotopes of diatom silica and petrographical characterisation of diatomaceous laminated sediments of Lago Chungara´ (northern Chilean Altiplano) have allowed us to establish its palaeohydrological evolution during the Lateglacial-early Holocene (ca. 12 000-9400 cal. yr BP). These laminated sediments are composed of light and dark pluriannual couplets of diatomaceous ooze formed by different processes. Light sediment laminae accumulated during short-term diatom blooms whereas dark sediment laminae represent the baseline limnological conditions during several years of deposition. Oxygen isotope analysis of the dark diatom laminae show a general d18Oenrichment trend during the studied period. Comparison of these d18Odiatom values with the previously published lake-level evolution suggests a correlation between d18Odiatom and the precipitation:evaporation ratio, but also with the evolution of other local hydrological factors as changes in the groundwater outflow as well as shifts in the surface:volume ratio of Lago Chungara´. The lake expanded (probably increasing this ratio) during the rising lake-level trend due to changes in its morphology, enhancing evaporation. Furthermore, the lake's hydrology was probably modified as the groundwater outflow became sealed by sediments, increasing lake water residence time and potential evaporation. Both factors could cause isotope enrichment. # Natural Environment Research Council (NERC) copyright 2008. Reproduced with the permission of NERC.
Note: Versió postprint del document publicat a: http://dx.doi.org/10.1002/jqs.1173
It is part of: Journal of Quaternary Science, 2008, vol. 23, num. 4, p. 351-363
Related resource: http://dx.doi.org/10.1002/jqs.1173
URI: http://hdl.handle.net/2445/102002
ISSN: 0267-8179
Appears in Collections:Articles publicats en revistes (Dinàmica de la Terra i l'Oceà)

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