Geology Site Account

Site name: Alsa Lodge Gravel Pit, Cambridge Road, Ugley

Grid reference: TL 515 264

Brief description of site:

Disused gravel pit with minor exposures of glacial sand and gravel. The pit is a denotified geological SSSI. The floor of pit is occupied by a shooting range and an auction house.

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Details

Alsa Lodge Pit is a disused sand and gravel pit with the potential to provide exposures of glacial gravel left behind by a glacier that filled this valley during the coldest period of the Ice Age about 450,000 years ago. This pit was a geological Site of Special Scientific Interest (SSSI) until it was denotified under Natural England's Geological Conservation Review in the late 1980s. Since then the walls of the pit have become overgrown and very little gravel can now be seen. The original gravel face was very high and is still very steep in places and it would not be difficult to expose a section through the gravel with the permission of the landowner.

This site is near the margins of the outcrop of the Woolwich and Reading Beds and the surface of the Chalk in this area is regularly pock-marked with solution pipes. These structures were once visible in the Alsa Lodge Pit, up to 2 metres wide and 3 metres deep, lined with reworked material of Tertiary age and filled with brown sandy clays containing lenses of gravel (Lake & Wilson 1990).

The part of the site occupied by the auction house is accessible when the auction house is open but the landowner's permission should be obtained to examine the faces of the pit.

The pit is a Local Wildlife Site.

Alsa Lodge gravel-pit in 1980 showing solution pipes in the Upper Chalk. Photo © British Geological Survey (P212598).