Sedimentación fluvial en la terraza media del Río Esla entre Vega de Infanzones y Villaquejida (León)

Abstract

In the south of the province of León the terrace levels rest over Upper Tertiary sediments. These materials were eroded by the fluvial system which produced each of the terrace layers. A study has been made in the Mean Terrace situated in the right bank of the Esla River, between Vega de Infanzones and Villaquejida area. This terrace is cut by a scarp which has given way to the lower terraces and to the present floodplain of the Esla River. The terraces consist of gravels facies, with wedges of sandy material. These materials originated from the recycling of older terraces, from the Upper Tertiary in the area, and also from the Paleozoic in the Cantabrian Range. The te1rnce consist of sediments left by braided stream systems with an abundant bed gravel load. The river bed would be divided in to several shallow and narrow channels. V arious types of bars would have developed in this channel: longitudinal, transversal and compound. These bars may be isolated, superposed, compound and with lateral acretion. The paleocurrents measured show a SSE flow direction.