The sand and gravel resources of the country around Whitchurch and Malpas, Clwyd, Cheshire and Shropshire : description of 1:25,000 sheet SJ 44, 54

The geological maps of the Institute of Geological Sciences, pre-existing borehole information and 99 boreholes drilled for the Industrial Minerals Assessment Unit form the basis of the assessment of the sand and gravel resources of the country around Whitchurch and Malpas. The glacial sediments of the district proved to be more complex than is shown on the published geological map. Glacial Sand and Gravel, present over much of the area in the south and east, shows rapid lateral and vertical variation in composition although sand-grade deposits predominate. Recorded thicknesses of overburden and waste also have a wide range. All the deposits in the district that 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 symmetrical 95 per cent probability level. The 1:25 000 map is divided into 7 resource blocks, containing between 2.9 and 37.2 km2 of sand and gravel. For each block the geology of the deposits is described, and the mineral-bearing area, the mean thicknesses 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.