Grid Reference NZ 631 146
BGS Sheet 34
OS Sheet 94
Forwarded as RIGS Part of Guisborough Forest 30/09/2003
Site Status SNCI
Brief Site Description Site 7 of 7. Disused alum quarry revealing exposures of Liassic Whitby mudstone and overlying Middle Jurassic Saltwick sandstone. Following abandonment after alum working, this quarry was used as a dump for ironstone spoil from mines around Slapewath. Shale was transported via an aerial ropeway.
Literature References Guisborough District Mines – Simon Chapman 2001
Summary Evaluation of Site’s Value and Importance
The sites in this group exhibit diverse examples of Liassic (Lower Jurassic) and Middle Jurassic deltaic deposits along with industrial archaeological remains.
Various industrial archaeological remains at the seven sites including ironstone extraction, the earliest alum quarries in England, and nineteenth century jet mining. Cass Rock Quarry was worked for alum shale between 1776 and 1805.
From its vantage point high on the escarpment of the Cleveland Hills, Cass Rock Quarry provides an ideal vantage point giving commanding views of East Cleveland and the coast.
Situated beside the Cleveland Way to the east of Guisbrough Forest, Cass Rock is potentially a good site at which to examine Upper Liassic shales, Middle Jurassic sandstone, and explore the site of a former alum quarry. Nature has reclaimed this quarry and care should be exercised around vertical faces.
Andrew Carter, John Waring