About the project

Grid Ref SJ 295 534

The Fossil Forest was discovered at Brymbo (Wrexham) in 2005 on the site of the old steelworks. During regeneration and development of this brownfield site, excavations revealed this unique geological feature.

The geology beneath the site is Upper Carboniferous in age (300my) and forms part of the Wrexham Coalfield. The geological exposures on the site comprise alterations of fine light coloured sandstones, mudstones and coal seams which are fairly typical of Carboniferous Coal Measure rocks found throughout the UK. However, Brymbo stands apart from many other coal measure localities in that the rocks found here contain a wonderful assemblage of fossilised plants preserved when an ancient flood deposited a sheet of sand on the prehistoric forest floor.

There are fossilised bases of giant clubmosses and stands of giant horsetails preserved in their original positions of growth as sandstone casts. Fossil trees are not uncommon in the Carboniferous Coal Measures, but it is exceptional to find an extensive stand of 20 or more ‘giant club-mosses’ along with thickets of giant horsetails. There are two exposed coal seams associated with the Fossil Forest and between them are shales, mudstones and ironstone nodules with abundant plant fossils and trace fossils. The plant fossils are beautifully preserved and have already yielded valuable scientific information.

Appleton, P. et al. 2011. The Brymbo Fossil Forest. Geology Today, 27: 107-113.;
Thomas, B.A. 2013. In situ stems: preservation and growth habits of the Pennsylvanian (Carboniferous) Calamitaleans based upon new studies of Calamites Sternberg 1820 in the Duckmantian at Brymbo, North Wales, UK. Palaeontology, doi: 1.1111/pala.12045).

It is widely recognised that the Brymbo Fossil Forest is of both national and international importance. The Fossil Forest has been identified as a Geological Conservation Review (GCR) Site and will soon be awarded SSSI status. At the moment the site is safe and secure, having been mothballed pending further action and redevelopment of the old steelworks site. Future plans are to develop the site into a top scientific and educational resource and tourist attraction.
Members of the BIGC continue to be involved in the site and our Treasurer, Professor Barry Thomas is the scientific advisor to Brymbo Heritage Ltd.

About the site

The Brymbo Fossil Forest is on the site of the former Brymbo Steelworks. There is no public access to this site. Assess is only allowed with the permission and supervision of the landowner.