Rhyolite Member

Formal (Van Adrichem Boogaert & Kouwe 1994).
Lithological description

Extrusive volcanic unit of acidic composition, massive, grey to pale pink, consisting of a microcrystalline groundmass with quartz phenocrysts. Petrologically interpreted as a rhyolite. The sediments overlying this member contain a number of thin volcanic beds (minor lava flows).

Depositional setting


Definition of lower boundary

Not yet defined

Definition of upper boundary

Not yet defined

Thickness indication
Up to 139 m.
Geographical distribution
Regional correlation
Radiometrically dated at 341 ± 30 Ma (Mobil Producing Netherlands Inc.; published in Sissingh 2004). Dating implies Visean age, i.e. early Carboniferous.
Depth (thickness) AH:
2157 to 2296 m (139 m)
Previous name(s)
Reviewed by (date)
Tom van Hoof, Geert-Jan Vis (2018).
Sissing, W. 2004. Palaeozoic and Mesozoic igneous activity in the Netherlands: a tectonomagmatic review. Netherlands Journal of Geosciences 83 (2), 111-134.
Van Adrichem Boogaert, H.A. & Kouwe, W.F.P. 1994. Stratigraphic nomenclature of The Netherlands; revision and update by RGD and NOGEPA, Section B, Devonian and Dinantian. Mededelingen Rijks Geologische Dienst, 50, 1-20.
Cite as
TNO-GDN ([YEAR]). Rhyolite Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from https://www.dinoloket.nl/en/stratigraphic-nomenclature/rhyolite-member.