Discoveries at great depth

The drilling campaign for the Einstein Telescope aims to provide more information about the composition and stability of the subsurface in the search area for the telescope. Our geologists can revel in both major and minor discoveries from the subsurface. What is it? Where does it come from? How old is it? Geert-Jan Vis, a geologist at TNO involved in the Einstein Telescope, has closely examined a few finds from recent drillings in Hombourg and Aubel (Wallonia) and listed the most remarkable findings.

Hombourg

62 meters depth

A cluster of washed-together small goniatites in the rock core of the Hombourg drilling. Goniatites are ammonite-like marine mollusks. Age: Namurian B (over 300 million years old).

58,7 meters depth

An imprint of the shell of a bivalve mollusk from the Pecten genus in the rock core of the Hombourg drilling. A modern variant of this is known as the edible scallop. This specimen, with over 300 million years, is well past its expiration date (Namurian B).

219 meters depth

A rock core from the Hombourg drilling with a coral (Siphonodendron martini) from the early Carboniferous. This rock is over 335 million years old.

Aubel

87 meters depth

A piece of rock core from the Aubel drilling with a typical alternation of light and dark colors known as zebra dolomite. This is the result of the (re)crystallization of minerals from very hot groundwater during mountain formation.

Detail

This is a detail of a piece of rock core from the Aubel drilling with a cavity in the zebra dolomite. Clearly recognizable crystals have formed here. The golden crystals are pyrite crystals (iron disulfide).

294 meters depth

A vein of light pink crystals in a rock core consisting of gray sandstone with claystone layers. The vein is likely composed of dolomite. The flowing hot groundwater from which the crystals grew long ago clearly carried away pieces of the gray rock.