Why is La Hague such a remarkable geological site?
To answer this question, we went to meet Yohann Poprawski, independent researcher and geologist, head of the company Géologic-Diffusion.

How does the Geopark appear obvious in the Hague?

The site offers, over a relatively small area, an incredible geological fresco. Of course, there are missing links, but above all there are rocks that allow us to retrace part of the geological history from a period 2,1 billion years ago!

How does this fresco appear on the ground?

In five main phases. The first dates back 2,1 billion years. The rocks dating from this period are the oldest in France. It is gneiss, in other words granite transformed by different geological phenomena. It can be observed for example in the Culeron cove. The 2nd phase dates from 540 to 600 million years ago. It is embodied in different geological forms of granite origin which can this time be observed in Goury. The 3rd phase dates back around 500 million years. The mountain ranges that formed here have eroded, leaving in their place various sandy and pebble beaches, such as in Ecalgrain Bay.

So many phenomena that explain the diversity of the landscapes of the Hague?

 Absolutely. This is also the case for the last two periods. In Herquemoulin, the rocks that we observe result from the formation of a mountain range which dates back around 300 million years and which must have been comparable to today's Alps! Finally, the last geological period represented is more recent. It dates back 200 years. That is to say, of a world that resembled ours. But the geology of this period, for example in Jardeheu, allows us to read the climatic variations and those of sea level. This is how we find, for example, fossilized pebbles strangely perched in the cliffs! It's just that in some of the periods that followed, sea levels were much higher than they are today.

The planned La Hague Geopark will tell the story of 2,1 billion years of Earth's history. Which makes it an absolutely major geological site. The Hague is also the remains of three mountain ranges, which erosion has slowly dismantled, the remains of explosive volcanic eruptions or the climate archives preserved for 220 years which also echo today's issues. today. The Anse du Culeron, the bay of Ecalgrain, the tip of Jardeheu or Herquemoulin constitute references for specialists and formidable field schools for curious audiences driven by a desire for knowledge on the history of the Earth or climates. The Hague is also a whole range of landscapes, which have long benefited from a high level of protection, a strong local attachment and a socio-economic dynamism which has made it possible to preserve them. All these links can be read in its landscapes from its cliffs, through its narrow coastal meadows with Irish accents, its moors, its vast dune massif, or through the beauty of its very well preserved built heritage.

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