Stratigraphic unit

Geological and lithological features

Transgressive Aeolian covers

Thin transgressive dune sheets (TDS) (< 1 m thick) of fine-grained sands covering mainly the structural highs (Barrier III). Locally, it can develop a small transgressive dune up to 2 - 3 m high.

BARRIER

IV

Holocene Barrier B

Active transgressive dunes close to the Atlantic Ocean, making part of the actual dune system building the Holocene Barrier IV.

Holocene Barrier A

Inactive transgressive dunes underlying the active ones. They seem to be coarser grained than actual ones and are anchored by native grass and bushes.

Holocene Lagoonal deposits

Fine-grained sands and silts interlayered with variable proportions of organic matter and clays in depressed areas.

Pleistocene Barrier III

Fine to medium-grained sands, mostly horizontal, parallel stratification, slightly compacted, and impregnated by Fe³⁺ hydroxides and clay.