In the past millions years many things have changed in the Delta-area. Nowadays the Netherlands is situated on the seacoast but this wasn’t always this way. The Netherlands have had many appearances:

More than 225 millions years ago:
PALEOZOICUM: carbonic stone.

225 to 65 millions years ago:
MESOZOICUM: lime stone, marl and deposition of sand.

65 to 2 millions years ago:
TERTIAIR: tertiary clay and sands.

2 millions years ago:
TIGLIEN: the Netherlands mostly has deposition materials from the North Sea.

1.8 millions years ago:
PREGLACIAL: many rivers flow through the Dutch landscape and ended in the North Sea.

200.000 years ago:
SALIEN: the ice age, the Netherlands was covered with a thick layer of ice.

2 millions to 10.000 years ago:
PLEISTOCEEN: the Netherlands had several formations: for instance peat, deposition of melting waters, glacial depositions.

10.000 ago
HOLOCEEN: a variety of layers, from a young layer of clay on peat to young and old beach deposition.

From 5500 years before Christ slowly peat depositions, clay, river materials and dunes covered the Pleistocene composition of the soil.