https://www.usgs.gov/publications/uranium-series-isochron-dating-el-castillo-cave-cantabria-spain-acheuleanmousterian
A massive flowstone layer, Level 23, near the base of the stratigraphic sequence in El Castillo Cave (Cantabria, Spain), is dated by the uranium-series...
el castillo caveuranium seriesisochron datingcantabriaspain