The Holocene record in the Villaviciosa Estuary (Asturias, Spain)

Abstract

The Holocene sedimentary sequence of the Villaviciosa Estuary, Asturias (Spain), is analysed based on 14 cores obtained in the uppermost part of the estuary. The depositional geometry and facies associations were studied, as well as their content in diatoms and foraminifera. Four samples were dated by 14C; the oldest, took at a depth of 4.55 m, gave a date of 7170 cal yrs BP. Other three samples were dated at 4.55 m in a core located further west (5920 cal yrs BP), at 2.55 in the centre of the valley (2850 cal yrs BP) and at 3.50 m in the extreme west (1290 cal yrs BP). The interpretation of the data obtained reveals that the sedimentary record of Villaviciosa Estuary is a complex infilling sequence occurring at pulses, by lateral accretion, the depositional system being displaced from east to west. In this coastal area, the sea level reached very quickly a relatively high position during the first half of the Holocene. This rise probably occurred at pulses, as shown by studies carried out in other estuaries of the Cantabrian coast. Moreover, the possibility that the midHolocene sea level in this coast was 4-5 m below the present-day level is also discussed.