Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physical Sciences and Mathematics
High Resolution Tephra And U/Pb Chronology Of The 3.33 – 3.26 Ga Mendon Formation, Barberton, Greenstone Belt, South Africa, Nicholas Burns Decker
High Resolution Tephra And U/Pb Chronology Of The 3.33 – 3.26 Ga Mendon Formation, Barberton, Greenstone Belt, South Africa, Nicholas Burns Decker
LSU Master's Theses
The Mendon Formation in the Barberton Greenstone Belt of South Africa marks the boundary between the Onverwacht and Fig Tree Groups. These groups are characterized by mafic to ultramafic volcanism and felsic volcanism with related epiclastic sedimentation, respectively. This transition marks the end of komatiitic volcanism in the Barberton Greenstone Belt and is accompanied by numerous impact-related spherule layers. This study characterizes the upper Mendon Formation texturally and geochemically over a wide areal extent and across structure and facies change in an attempt to better understand the evolution of tectonic processes at this boundary. A suite of whole rock and …
Temperature And Pressure Conditions Of Archean Amphibolite-Granulite Facies Metamorphic Xenoliths From The Eastern Beartooth Mountains, Montana And Wyoming, Usa, Celina N. Will
LSU Master's Theses
Compositionally-diverse Archean metamorphic rocks occur as xenoliths within the well-dated 2.8 Ga granitic gneisses that volumetrically-dominate the eastern Beartooth Mountains of the northern Wyoming Province. Common mafic lithologies in the Quad Creek-High Line Trails-Christmas Lake-Wyoming Creek-Line Creek Plateau area include granitic gneiss, amphibolites, mafic granulites and biotite and garnet-bearing peraluminous gneisses. The region also has sillimanite-biotite ± cordierite ± garnet gneisses and migmatites, as well as a single occurrence of a noteworthy orthopyroxene-cordierite gneiss with late-stage anthophyllite. A combination of detailed petrographic analysis and thermobarometric modeling were used to constrain the metamorphic conditions of the xenoliths prior to inclusion in …