Magnetic susceptibility and ¿18o characterization of variscan granites related to w-(Mo) and sn-(w) mineralizations: Lamas de olo pluton case study [Caracterização da suscetibilidade magnética e ¿18 o de granitos variscos relacionados com mineralizações de w-(Mo) e sn-(w): exemplo do plutão de lamas de olo]

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Cruz, C (Author) Other; Sant'Ovaia, H (Author) FCUP; Noronha, F (Author) FCUP

Journal

Title: Comunicações Geológicas

Vol. 103

Pages: 143-147

ISSN: 0873-948X

Publisher: LNEG - Laboratório Nacional de Energia e Geologia

Indexing

Scopus - 7 Citations

Other information

Authenticus ID: P-00R-W4T

Abstract (EN): The ¿Iberian Sn-W metallogenic province¿, located in central-northern region of Portugal is characterized by the presence of various W, W-(Sn), W-(Mo) and Sn deposits related with synorogenic Variscan granites, mainly emplaced during the post-collisional stage (321 to 290 Ma). The granites can be classified into magnetite-or ilmenite-type granites according to their magnetic susceptibility. These two types of granites result from different oxygen fugacities during the granitic magma genesis, and have also distinctive whole-rock ¿18 O values. Thus, higher values (between 12.3 ¿ and 13.5 ¿) indicate a crustal origin, while the low ¿18 O (between 8.9 ¿ and 12.2 ¿) suggests a mantle origin and/or source regions dominated by mafic and meta-igneous rocks. Major W-(Sn) and Sn ore deposits are more related to ilmenite-type granites with high ¿18 O, while W-(Mo) deposits are related with magnetite-type granite with lower ¿18 O values. © 2016 LNEG ¿ Laboratório Nacional de Energia e Geologia IP.

Language: English

Type (Professor's evaluation): Scientific