The sand and gravel resources of the country north of Harlow, Essex : description of 1:25,000 resource sheet TL 41

The geological maps of the Institute of Geological
Sciences, pre-existing borehole information and 98
boreholes drilled for the Industrial Minerals
Assessment Unit, form the basis of the assessment of
sand and gravel in the area north of Harlow, Essex.
All deposits in the area which might be potentially
workable for sand and gravel have been investigated
and a simple statistical method has been used to
estimate the volume. The reliability of the volume
estimates is given at the 95 per cent probability level.
The l :25 000 map is divided into five resource blocks
containing between 8.3 and 14.2 km2 of sand and
gravel. For each block the geology of the deposits is
described and the mineral-bearing area, the mean
thickness of overburden and mineral, and the mean
gradings are stated. Detailed borehole data are also
given. The geology, the position of the boreholes and
the outlines of the resource blocks are shown on the
accompanying map.