The geological maps of the Institute of Geological Sciences, pre-existing borehole information
and seventy-three boreholes drilled specifically for assessment purposes (of which sixty-one
were part of a feasibility study conducted in 1966-67 and twelve were drilled subsequently) form
the basis of the assessment of sand and gravel resources in the Maldon area, Essex.
All deposits in the area which might be potentially workable for sand and gravel (mineral ) have
been investigated geologically 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 confidence level.
The 1:25 000 map is divided into resource blocks, each ideally containing approximately
10 km2 of sand and gravel. For each block the mineral bearing area, the mean thickness of
overburden and mineral, and the mean grading are given and the geomorphology and geology of the
deposits described.
The position of the boreholes and exposures, the geology and topography and the outlines of the
blocks are shown on the accompanying map TL 80. Detailed borehole data are given
