Stable isotope geochemistry of the Okenyenya igneous complex, Namibia : constraints on contamination and fluid interaction

 

Show simple item record

dc.contributor.author Martinez, Iúma Aparecida en_ZA
dc.date.accessioned 2016-09-06T14:44:02Z
dc.date.available 2016-09-06T14:44:02Z
dc.date.issued 1995 en_ZA
dc.identifier.citation Martinez, I. 1995. Stable isotope geochemistry of the Okenyenya igneous complex, Namibia : constraints on contamination and fluid interaction. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/21694
dc.description.abstract The δ¹⁸O values of coexisting silicate minerals in rocks comprising the tholeiitic olivine gabbro - quartz monzodiorite suite, are consistent with the attainment of isotope equilibrium and largely closed system conditions. The majority of the temperatures calculated by conventional mineral-pair thermometers are spurious, as a result of oxygen isotope diffusion during slow cooling. Closure temperatures for oxygen diffusion of 560ᵒC and 540ᵒC have been calculated for the anorthite-clinopyroxene and plagioclase-biotite mineral-pairs in the tholeiitic leucogabbro sample, respectively. The oxygen isotope data for the silicate minerals are consistent with contamination of the magmas by material having the oxygen isotope composition of the southern Etendeka rhyolite (δ¹⁸O = + 11.5‰). It is suggested that the assimilant may have been derived from the same source as the southern Etendeka rhyolite, as opposed to the rhyolite itself, which would be expected to occur at a high crustal level. Simple oxygen and strontium isotope mass balance calculations are used to constrain the lower (14 % and 19.5 % respectively) and upper (57 % and 71.6 % respectively) limits of the maximum possible amount of a southern Etendeka rhyolite contaminant assimilated. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Geological Sciences en_ZA
dc.subject.other Geochemistry en_ZA
dc.title Stable isotope geochemistry of the Okenyenya igneous complex, Namibia : constraints on contamination and fluid interaction en_ZA
dc.type Thesis / Dissertation en_ZA
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Geological Sciences en_ZA
dc.type.qualificationlevel Masters en_ZA
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image


Files in this item

This item appears in the following Collection(s)

Show simple item record