Sedimentological and palynological records since 10 ka BP along a proximal-distal gradient on the Armorican shelf (NW France)

New findings acquired in Armorican shelf (core MD08-3204 CQ: Bay of Quiberon and core VK03-58bis: South Glénan islands) depict Holocene paleoenvironmental changes since 10 ka BP through a multi-proxy dataset including sedimentological palynological data. First, grain-size analyses AMS-14C dates show common sedimentary history for both study cores. The slowdown the relative sea level (RSL) rise was accompanied by drop sedimentation rates between ∼8.3 5.7 BP; had been relatively higher at onset Holocene. This interval led to establishment shell-condensed level, identified VK03-58bis “Turritella layer” interpreted as marker Maximum Flooding Surface. Palynological data (pollen dinoflagellate cyst assemblages) CQ argue an amplification fluvial influence Highstand System Tract (i.e., mixed marine fluviatile influences on platform) then RSL rates. On shelf, Anthropogenic Pollen Indicators (API) has better detected 4.2 BP, due not only increase human impact but also stronger during Late data, recorded 8.5–8.3 along inshore-offshore gradient, demonstrate complexity signals such i) that promotes some pollen taxa (Alnus Corylus) from proximal areas ii) macro-regionalization palynomorph sources distal In addition, comparison tracers, API, over last 7 kyrs with Brittany coastal mid-shelf sites subject northern vs. southern Loire catchment areas, shows major hydro-climatic effect reconstructed signals. Strengthened subpolar gyre (SPG) dynamics, combined recurrent positive North Atlantic Oscillation (NAO) configurations, appear responsible increased winter precipitation discharge Europe, Brittany. Conversely, weakened SPG intervals, associated negative NAO-like modes, are characterized intensified Europe. Interestingly, infra-orbital timescale, we record peaks API periods strengthened (/weakened) dynamics detritic-organic matter inputs (/Loire) watersheds.