Volcanic rocks of the Witwatersrand Triad, South Africa. II: petrogenesis of mafic and felsic rocks of the Dominion Group
- Marsh, Julian S, Bowen, Michael P, Rogers, N W, Bowen, Teral B
- Authors: Marsh, Julian S , Bowen, Michael P , Rogers, N W , Bowen, Teral B
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140443 , vital:37889 , https://doi.org/10.1016/0301-9268(89)90075-2
- Description: A bimodal suite of volcanic rocks builds the bulk of the Dominion Group which, with an age of ∼ 2.72 Ga, is the oldest cover sequence overlying the granite-greenstone Archaean basement of the Kaapvaal craton in the western Transvaal, South Africa. The basic lavas are relatively rich in SiO2 (50–58%) and aphyric and exhibit a large compositional range. This variation is typically tholeiitic in that it is characterized by strong enrichment of Ti, Fe, and V in differentiated lavas.
- Full Text: false
- Authors: Marsh, Julian S , Bowen, Michael P , Rogers, N W , Bowen, Teral B
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140443 , vital:37889 , https://doi.org/10.1016/0301-9268(89)90075-2
- Description: A bimodal suite of volcanic rocks builds the bulk of the Dominion Group which, with an age of ∼ 2.72 Ga, is the oldest cover sequence overlying the granite-greenstone Archaean basement of the Kaapvaal craton in the western Transvaal, South Africa. The basic lavas are relatively rich in SiO2 (50–58%) and aphyric and exhibit a large compositional range. This variation is typically tholeiitic in that it is characterized by strong enrichment of Ti, Fe, and V in differentiated lavas.
- Full Text: false
Geochemical constraints on coupled assimilation and fractional crystallization involving upper crustal compositions and continental tholeiitic magma
- Authors: Marsh, Julian S
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140432 , vital:37888 , https://doi.org/10.1016/0012-821X(89)90021-6
- Description: The commonly analyzed trace elements in tholeiites can be subdivided into three groups depending on their sense of enrichment or depletion in upper continental crust in relation to fractional crystallization. Lithophile incompatible elements are enriched in crustal rocks and by fractional crystallization, whereas compatible transition elements such as Ni and Cr are depleted. A small third group comprising Ti, V, Fe, and sometimes P, enrich with crystallization but are depleted in the crust.
- Full Text: false
- Authors: Marsh, Julian S
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140432 , vital:37888 , https://doi.org/10.1016/0012-821X(89)90021-6
- Description: The commonly analyzed trace elements in tholeiites can be subdivided into three groups depending on their sense of enrichment or depletion in upper continental crust in relation to fractional crystallization. Lithophile incompatible elements are enriched in crustal rocks and by fractional crystallization, whereas compatible transition elements such as Ni and Cr are depleted. A small third group comprising Ti, V, Fe, and sometimes P, enrich with crystallization but are depleted in the crust.
- Full Text: false
Oxygen isotope geochemistry of the Mesozoic volcanics of the Etendeka Formation, Namibia
- Harris, Chris, Smith, H Stuart, Milner, Simon C, Erlank, Anthony J, Duncan, Andrew R, Marsh, Julian S, Ikin, Nicholas P
- Authors: Harris, Chris , Smith, H Stuart , Milner, Simon C , Erlank, Anthony J , Duncan, Andrew R , Marsh, Julian S , Ikin, Nicholas P
- Date: 1989
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143272 , vital:38219 , https://doi.org/10.1007/BF00371087
- Description: The Etendeka Formation volcanics consist of a bimodal association of basalts and quartz latites. Forty three new whole rock oxygen isotope analyses are reported for all the major magma types. All the rocks except a minor suite of dolerites have higher δ18O values than normal mantle. The basic rocks (average of 29=8.8‰) have significantly different δ18O to the acid rocks (average of 10=14.4‰). These data are apparently consistent with previously published petrogenetic models, which propose that the basalts were affected by crustal contamination and that the quartz latites are crustally derived.
- Full Text: false
- Authors: Harris, Chris , Smith, H Stuart , Milner, Simon C , Erlank, Anthony J , Duncan, Andrew R , Marsh, Julian S , Ikin, Nicholas P
- Date: 1989
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143272 , vital:38219 , https://doi.org/10.1007/BF00371087
- Description: The Etendeka Formation volcanics consist of a bimodal association of basalts and quartz latites. Forty three new whole rock oxygen isotope analyses are reported for all the major magma types. All the rocks except a minor suite of dolerites have higher δ18O values than normal mantle. The basic rocks (average of 29=8.8‰) have significantly different δ18O to the acid rocks (average of 10=14.4‰). These data are apparently consistent with previously published petrogenetic models, which propose that the basalts were affected by crustal contamination and that the quartz latites are crustally derived.
- Full Text: false
Tying up the continents
- Authors: Marsh, Julian S
- Date: 1989
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143282 , vital:38220
- Full Text:
- Authors: Marsh, Julian S
- Date: 1989
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143282 , vital:38220
- Full Text:
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