GEOCHEMISTRY OF A SILURIAN METABENTONITE AND ASSOCIATED APATITE FROM THE NORTH ESK INLIER, PENTLAND HILLS

Geochemical data are presented for an important metabentonite horizon within the Upper Llandovery and early Wenlock succession of the North Esk Inlier of the Pentland Hills. The metabentonite marks a horizon of rapid faunal change, with a rich assemblage below and an impoverished assemblage above. Characterizing the metabentonite and its constituen t apatite crystals on the basis of rare earth and other trace elements has allowed two separate outcrops to be correlated locally and the so urce magma type identified. In addition, these apatite data provide a chemical fingerprint with which to correlate this horizon with similar occurrences elsewhere in northern Europe.