A FREE talk entitled The Geology Of The Chevin by Bill Fraser takes place on Tuesday, November 19 at 7.30pm at The Black Horse, Westgate, Otley.

The event has been organised by The Friends of Chevin Forest and a spokesperson said: "The Chevin is a north-facing escarpment comprised of shales and sandstones laid down 315 million years ago in the Carboniferous era. These rocks were deposited in a delta as part of a continent (Laurentia) in a tropical region by a southwards flowing river system which laid down the bulk of millstone grit deposits into a shallow, tropical sea. Initially low-lying of course, these were subsequently uplifted and faulted during the Pennine mountain-building period (or Variscan Orogeny) as the Iapetus Ocean (precursor to the Atlantic) closed.

"Extensive quarrying on the Chevin enables us to see the geological features and informs our understanding of the soils that evolve from them and the ecosystems which depend on them.

"Bill Fraser, of West Yorkshire Geology Trust and author of the Chevin Geology Trail will bring these events to life and helping us to imagine the landscape so that we can bring expertise to underpin our understanding of the beauty of the area."