The geochemistry of the Gough Island basalts and their mantle source region

Ten Gough Island primary magma compositions were calculated for use in constrained forward modelling. The primary magma compositions were calculated by the addition of 14-28% clinopyroxene and equilibrium olivine, in equal proportions, back into the primitive lava compositions in 1 % increments until an Mg# of 69 was reached. Constrained forward modelling methods were used in determining the chemical and mineralogical nature of the mantle source region as well as the required melting parameters required in producing the Gough Island suite of lavas. The models indicate that the full compositional range, as well as the crossing REE patterns at Dy, can be produced through ~5-8% equilibrium melting of a mantle source region composed of garnet lherzolite or ~30-50% melting of a garnet pyroxenite source.

Grantor dc:publisher.institution

Department of Geological Sciences

Year dc:date.issued

2008

Author dc:creator

• Long, David J

Advisors dc:contributor.advisor

• Le Roex, Anton
• Class, Cornelia

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/4209

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/4209