Variación de las tasas de sedimentación en el Complejo Detrítico Superior del Delta del Llobregat (Barcelona): su relación con causas eustáticas, climáticas y antrópicas

Abstract

Sediment accumulation rates have been calculated for the Llobregat Delta and compared to eustasy, climate and land use. Radiometric ages show slow (less than 1 mm/yr) sediment accumulations between 12180±60 BP (14565±715 cal BP) and ~4100 BP (4500 cal BP) and faster rates (12 to 25 mm/yr) younger than ~4100 BP (4500 cal BP). Within this trend of increasing sediment accumulation rates are two peaks of high sediment accumulation; one occurring during the Visigoth period (VI-VIII century) to Upper Medieval Age (X-XIV century) and the second during the economic recuperation (XVIII century). The initial slow sediment accumulation rate is attributed to high rates of accommodation produced by the rapid Holocene transgression and little sediment supply. Following a slower rate of creation of accommodation space, sediment started to accumulate at the mouth of the river and prograde on the shallow shelf. The pulses in sediment accumulation coincide with and are interpreted to increasing pressure anthropomorphic activity together with peaks of aridity