Geology Site Account

Site name: Great Holland Pits Nature Reserve

Grid reference: TM 2022 1924

Brief description of site:

Former gravel pit in the Cooks Green Gravel. Now an Essex Wildlife Trust nature reserve. Site of geological interest with potential for geological education.

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Summary of geological interest

A former gravel pit in the Cooks Green Gravel (laid down by the Thames-Medway river) that is now an Essex Wildlife Trust nature reserve. No current visible exposure of gravel but there are level areas of gravel present beneath scrub that could be cleared to reveal a wide variety of rock types. These are mostly cobbles and boulders left behind by the quarry operations. There is an opportunity here to promote geology by exposing these areas of gravel and allowing visitors to identify rock types and speculate on how they got here. The Cooks Green Gravel is about 600,000 years old.

Unfortunately it is not possible to create a vertical section through the gravel beds as all gravel banks in the reserve appear to be heaps left over from quarrying operations.

The route of the River Thames and River Medway across the Tendring peninsula about 600,000 years ago during deposition of the Wivenhoe Gravel and Cooks Green Gravel. The present outcrops of these gravels are shown. Illustration © David Bridgland.