COLLOFORM GOLD IN COAL FROM SOUTHERN WALES

Geochemically significant concentrations of particulate gold in the We stphalian coals of the South Wales coalfield are situated on the coal cleat and are associated with a complex sulfide assemblage. Gold grain s up to 100 mum long and more than 20 mum thick display a colloform mi crotexture, suggesting an origin through late Variscan, low-temperatur e ground-water circulation. These discoveries provide additional const raints on the timing and rates of coal evolution.