Barnt Green Road Quarry – Lickey Quartzite

On a wet Saturday 3rd February 2018 six keen and dedicated volunteers undertook a clear up of the Barnt Green Road Quarry. Led by Alan and Julie, other volunteers included Ken, Holly and Jane – pictured below. Clearing away the ever growing vegetation and removing the scree enables visitors to see the Ordovician Lickey Quartzite and inter-layered clay beds. The volunteers focussed on the eastern side and southern end of the quarry. At the southern end a north west south east trending fault can be seen where the vertical westward dipping beds are faulted against eastward dipping beds.

Several years ago funding enabled this quarry to be cleared of vegetation to expose this classical site which had been overgrown since the early 1900’s, It was back in the 1880’s when Charles Lapworth, first Professor of Geology at Birmingham University, used to visit this quarry to undertake detailed geological work.

The Geology

The quartzites were formed by sand being deposited at the bottom of a shallow sea. Quartzite is hard, blocky, sharp edges, severely fractured in parts. Originally deposited as sand the sediment has been compacted sufficiently at depth  to fuse the grains together  in a silica cement making it devoid of porosity. The clays in the quarry are not typical grey marine clays, but red in colour. They are hydrophyillic, possibly bentonite of volcanic origin.

Charles Lapworth had noted that some of the quartzites included reworked older Barnt Green Volcanics. However he also found evidence of volcanic inclusions from another source, which were believed to be active volcanoes at the time of deposition. There was plenty of volcanic activity taking place to the north during the Caledonian mountain building period which could have provided the source material.

The closing of the Iapetus Ocean during Ordovician and Silurian times was probably when these rocks were folded.  The area is considered to be part of the “Avalon Composite Terrane. Central to this composite terrne is the triangular-shaped Midlands Microcraton; within it, the north-south aligned Malvern Line (or ‘Malvern Lineament’) divides the Wrekin Terrane in the west from the Charnwood Terrane in the east”. The Lickey Hills horst feature, of which this quarry is part, may be the result of later Hercynian movements which commonly reactivated earlier faults.