996 resultados para Back Bay Fens
Resumo:
A historical record for the deposition of lead in Swansea Bay, Bristol Channel, U.K. has been determined together with isotopic compositions. Analysis of the isotopic composition of lead in cores, dated by 210Pb-210Po chronology, illustrated a post ~ 1850 influx of lead originating from technically produced materials. Since ~ 1850 there has been a × 3 increase of lead in sediments of which only 25–30% can be accounted for from technical sources; the remainder is presumed to be derived from working of the South Wales Coal Measures.