[3][4] The site is composed of two disused gravel pits which are important for the study of the Lower Pleistocene.

[5] The geological deposits include sands, silts and gravels which have yielded fossils of marine and non-marine mollusca, foraminifera and vertebrates.

Studies of fossils from Blake's Pit have demonstrated changes from temperate (Bramertonian) to cold (Pre-Pastonian) climatic conditions.

Bramerton Common Pit has yielded a rich fossil vertebrate fauna including marine fishes and extinct species of gomphothere mastodont, otter and vole.

Both sites are nationally important for understanding early Pleistocene environments and faunal changes in Britain.