Holocene paleoenvironmental and relative sea-level changes in the Santona estuary, Spain

The benthic foraminifera of the Holocene succession of 3 boreholes in the Santona estuary (Bay of Biscay, northern Spain) have been analyzed. Two types of foraminiferal assemblages have been distinguished: indigenous and exotic (derived from the open coast). They have been used to interpret the environments of deposition, which range from brackish low-marsh and intertidal to near-marine intertidal with different amounts of open-sea influence. Two different upward-shallowing sequences have been identified (similar to 8000 BP and similar to 3000 BP) and interpreted as showing episodic increase of sea level in the study area.