The “International European Camp Lignin 2022” took place from July 10 to August 10, 2022, in the commune of Colmars, Alpes-de-Haute-Provence, France. It brought together 34 participants with diverse profiles, aged from 20 to 81, with 26% women, and 8 nationalities.

The difficulties of access linked to the high altitude are mitigated by the helicopter allowing to transport exploration equipment and logistics, as well as food, and to install a comfortable temporary camp allowing to support the climatic conditions.

The objective was to find an extension to the known caves in order to reach the deep network of the Underground Coulomp and the Chamois Cave, 6 km away and 1000 m below. The Lignin sinkhole n° 14 was extended in the Plan B series to -161 m, and the sinkholes no.3, no.12, and no. 15 were dug to -13 m, -8 m, and -3 m, respectively.

A study on the age of the karst of glacial origin is in progress, by U/Th dating of speleothems. Several publications of the results should appear by the end of the year and the website will be gradually updated.

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