Essex Field Club on Facebook

Video about the Club

Aplocera plagiata
find out more... Treble-bar  Aplocera plagiata Copyright: Graham Ekins

Essex Field Club
Essex Field Club
registered charity
no 1113963
HLF Logo A-Z Page Index

Visit Our Centre

EFC Centre at Wat Tyler Country ParkIn January we are only open to the public at our centre at Wat Tyler Country Park on Wednesdays 10am-4pm.
Autumn recording Record Grey Squirrel Record Fly Agaric
Record Ivy Bee
Record Wild Teasel
Record Sloe, Blackthorn
Record Garden Spider Record Nigma walckenaeri spider

Geology Site Account

A-Z Geological Site Index

College Wood Gravel Pits, BLACKMORE, Brentwood District, TL623015, General geological site

show OS map    

College Wood Gravel Pits, Blackmore


College Wood, a large, ancient wood near Blackmore, contains a number of overgrown and disused gravel pits. The origin of this gravel, known as Stanmore Gravel, is unclear. It dates from the early part of the Ice Age and may have been deposited by northward-flowing tributaries of the pre-diversion Thames, or it may be of marine origin. Exposures of this gravel therefore have the potential for future research. The pits are situated in private woodland with no public access.


Site description

The sand and gravel exposed in the College Wood pits is referred to on geological maps as ‘Stanmore Gravel’ and it occurs elsewhere on the high ground of Brentwood district. How it was formed has been debated by geologists since the 19th century. Its origin is still unclear today although one theory is that it was laid down by a river, probably over one million years ago, during the early part of the Ice Age. This was at a time when the Thames flowed across what is now North Essex and Suffolk. The river in question may therefore have been a northward-flowing tributary of the Thames. See Ellison (2004) for a discussion about the origin of this deposit.

The gravel in College Wood contains vein quartz, quartzite and rare Lower Greensand pebbles. The gravel outcrops here and in nearby Parsons Spring (in Chelmsford District) are similar and are characterized by rather different pebble assemblages compared to occurrences elsewhere in the area (Millward et al 1987). Future research here may therefore be important in helping to establish an origin for this enigmatic deposit.

The geological survey memoir for the Epping District (Millward et al 1987) calls this gravel ‘Older Head’. The British Geological Survey’s picture library contains an image of the gravel in one of these pits at TL 6236 0169.

Gravel-pit in College Wood near Blackmore. Cryoturbated, rather clayey sand and gravel. The white angular pebbles are patinated flint. The well-rounded pebbles consist mostly of flint but some vein quartz. Photo © British Geological Survey (P212163).


if you have an image please upload it

Reference: Ellison 2004 (P. 52), Milward et al 1987 (p. 25, 26, & 28).

Geology Site Map
A-Z Geological Site Index