Tectonic and mining induced fault reactivation around Barlaston on the Midlands Microcraton, North Staffordshire, UK

The North Staffordshire Coalfield occupies the northern apex of a triangula r area of late Proterozoic continental crust, the Midlands Microcraton. Mos t faults identified at surface in the late Carboniferous rocks originated e ither as a result of reactivation of structure during the Variscan orogen i n the late Carboniferous, or its collapse in the early Permian. The coalfie ld has been extensively undermined and many examples of mining-induced faul t movement have been recorded in the Barlaston area between 1960-2000, The style of ground deformation observed in the area is described. Most movemen ts have resulted in a series of distinct, extensive, fault scarps and fissu res on the ground surface, causing widespread damage to structures, propert y, underground utilities and land. Several phases of fault movement have oc curred, separated by periods of relative stability. Fault scarps may occasi onally reach 2 m high, being indicative of multi-seam (3+) mining operation s. These are restricted to a few metres in width but reach several hundreds of metros in length. The reasons why so many faults have been reactivated around Barlaston, why the surface expression of the faults are different in Carboniferous and Triassic outcrops, and why some faults appear to have re activated since the cessation of mining are discussed.