Morphosedimentary and phytogeography reconstruction of the middle section of the river Jarama (Madrid, Spain) during the second half of the Holocene

Two sites located on the alluvial plain of the Jarama River, near Madrid, Spain, have been studied using geological, palynological and xylological techniques. Uniquely for this region, numerous wood subfossils of Alnus and Ulmus have been found together with an strobile of Pinus halepensis. This has allowed the stablishment of a coherent radiocarbon chronology, which demonstrates that these sedimentary environments began to develop during the mid-Holocene. The dated sediments, which also contains appreciable amounts of pollen, have been deposited upon older palaeosols which has in turn developed directly on the geological substrate. Palynological analyses of these levels have provided valuable insights into the floristic composition of the communities associated with the different biotopes present in the area. As a result of these multiproxy analyses an interpretation of Holocene landscape history and vegetation dynamics is presented.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasFALSEEspaña. Dirección General de Investigación Científica y Técnicapu