Holocene tidal levels and sedimentation rates using a diatom-based palaeoenvironmental reconstruction: the Tees estuary, northeastern England

An established diatom-based tidal level transfer function is used in combin ation with the present-day relationship between sedimentation rate and alti tude to reconstruct Holocene tidal sediment accretion for the Tees estuary, northeastern England. The results from five cores reveal two periods of en hanced sedimentation, the earlier of which (8000-6000 cal. BP) is related t o relatively rapid sea-level rise and increasing tidal range. The later pha se of increased tidal sedimentation also reflects an enhanced marine influe nce after c. 3000 cal. BP, but may also be attributed to climate- and human -induced changes in terrestrial sediment flux to the coastal zone. Comparis on of the reconstructed sediment accretion rates with actual rates calculat ed from radiocarbon and luminescence dated sedimentary horizons reveals tha t this diatom-based approach overestimates sediment accretion by a factor o f three. This overestimation is considered to be due to the contemporary se diment flux being an inappropriate analogue for the mid- to late Holocene r ather than to any significant methodological flaws in the approach.