BRITISH GEOLOGICAL Survey has published new 1:1,500,000 scale gravity and magnetic maps of Britain, Ireland and adjacent areas. Both maps cover an area from the Faroes in the north to the Channel Islands in the south, and from west of Ireland to close to the Norwegian coast.
The maps are the culmination of gravity and magnetic surveys lasting over half a century, ranging from land gravity surveys starting in the 1940s to marine gravity surveys in the 1970s and 1980s and on to the latest satellite-derived gravity surveys of the 1990s. Magnetic surveys started in 1955 as analogue airborne surveys over mainland Britain, and include offshore airborne surveys from the 1960s to digital airborne surveys of the remote areas around Rockall and the Faroes, together with recent deep sea shipborne surveys.
Maps are available in either flat or folded form at pounds4.95 each, excluding post and packing, from the BGS, Keyworth, Nottingham NG12 5GG, tel 01159 363251, fax 01159 363488.
Memoir shows tropical Teesside
NEW GEOLOGICAL memoirs for the country around North- allerton, and for the Stoke on Trent area, are available from the British Geological Survey.
The Northallerton memoir covers an area straddling the Vale of York and part of the Teesside plain, with the Cleveland Hills in the east. Rocks in the area range in age from 330 million to 150 million years, and show changes that include periods of hot dry deserts and tropical seas. Thick deposits on the low ground in the west were left behind in the last ice age, showing 'excellent evidence of a retreating ice front about 13,000 years ago', says the BGS.
Over the last 150 years, the mineral wealth of the Cleveland Hills gave rise to the industrial complex of Teesside, and left a legacy of mining and quarrying, including workings for ironstone, jet, alum and coal.
Lying at the south western end of the Pennines, the district described in the Stoke on Trent memoir includes the Potteries conurbation, which developed as a result of rich coal, clay and ironstone resources.