期刊名称:Cuadernos de Investigación Geográfica = Geographical Research Letters
印刷版ISSN:0211-6820
电子版ISSN:1697-9540
出版年度:2013
卷号:39
期号:1
页码:179-193
DOI:10.18172/cig.2005
出版社:Universidad de La Rioja
摘要:Lake La Parra (39º 50’, 1º 52’, 1014 m) is a small (1 ha), relatively deep (Zmax = 17.5 m), freshwater (TDS = 356 mg/L) monomictic lake with a circular morphology (116 m diameter), developed in a doline that intercepted the local Jurassic-Cretaceous aquifer. It is part of a karstic lake complex of seven lakes located in the Iberian Range (Cuenca, East of Spain). Sediment cores obtained in the central part of the lake were analysed using sedimentological, microscopic, geochemical and physical techniques. The ca. 7 m long sequence is mainly composed by clastic carbonated sediments, characterized by a high variability of sedimentary facies, indicative of large fluctuations in the sediment delivery to the lake. Chronology is based on 7 AMS radiocarbon dates. The depositional evolution of La Parra sequence reflects a high hydrological variability during the last 1600 years. Prior to the Roman Epoch, La Parra doline was dry and only became a lake after 4th century AD. Shallower conditions and higher sediment input occurred during the Medieval Climate Anomaly (MCA) and more humid phases during the Little Ice Age (LIA). The main human impact in the lake and the watershed environment is related to changes in the land uses (transhumance, deforestation, crops) during the Middle Ages (500-1400 DC) and during 18th- mid 20th centuries.