The Iberian-Roman Humid Period (IRHP, 2600-1600 cal yr BP), is the most humid phase of the last 4000 yr in southern Spain as recorded in the sedimentary sequence of Zoñar Lake (37°29′00″N, 4°41′22″ W, 300 m a.s.l.). A varve chronology supported by several AMS 14C dates allows study of the lake evolution at annual scale in response to human impact and climate changes. There are four climate phases within this period: i) gradual transition (2600-2500 yr ago, 650-550 BC) from a previous arid period; ii) the most humid interval during the Iberian-Early Roman Epoch (2500-2140 yr ago, 550-190 BC); iii) an arid interval during the Roman Empire Epoch (2140-1800 yr ago, 190 BC AD 150); and iv) a humid period synchronous with the decline of the Roman Empire (1800-1600 yr ago, AD 150-350). Varve thickness and geochemical proxies show a multi-decadal cyclicity similar to modern North Atlantic Oscillation (NAO) (60, 20 years) and solar variability cycles (11 yr). The timing and the structure of this humid period is similar to that described in Eastern Mediterranean and northern European sites and supports the same large-scale climate control for northern latitudes and the Mediterranean region.
Bibliographical noteFunding Information:
Financial support for this study was provided by the Spanish Ministry of Science and Education (projects LIMNOCLIBER REN 2003-09130-CO2-02, IBERLIMNO CGL2004-20236-E, CALIBRE CGL2006-13327-C04/CLI, CGL-2006-2956-BOS and CGL2007- 65572- CO2- 01), Andalusian Government Predoctoral Fellowship and the Andalusian Government (PAI group RNM-328, RNM- 309 and project P06- RNM- 02362). We thank Penélope González-Sampériz for pollen identification and interpretation. We are grateful to Suzanne Leroy, an anonymous reviewer and the editors David J. Meltzer and Alan Gillespie for their criticisms and suggestions that improved the manuscript. Finally we thank LRC (University of Minnesota, USA), and particularly to Doug Schnurrenberger, Mark Shapley and Anders Noren for making possible the 2004 expedition. We gratefully acknowledge funding from DAAD (German Academic Exchange Programme) and the Acciones Integradas Hispano-Alemanas Project D/07/13363.
Copyright 2011 Elsevier B.V., All rights reserved.
- Iberian-Roman period
- Lake varve chronology
- Mediterranean region
- Solar variability
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