Petrochemical and 18 O/ 16 O Characteristics of ‘W-Skarn Associated’ and ‘W-Barren’ Granitoids in the (E-) Pyrenees and NW Portugal

Petrochemical and 18O/16O results are presented concerning the occurrence of tungsten skarn deposits associated with Hercynian granitoids in the (E-) Pyrenees and NW Portugal. The investigation comprises a comparison of the bulk-rock, major trace element and oxygen isotope behaviour of granitoids in the ‘I-type’ Pyrenean and ‘S-type’ Portuguese magmatic suites. In more detail the magmatic and post-magmatic element distributions and 18O/16O characteristics are compared of the W-skarn associated granites of Costabonne and Covas, the (almost) W-barren granite of Batere and the Arga granite which is associated with Sn-(Ta-W) aplopegmatitic mineralizations.