Regional geochemistry of the Karoo igneous province
- Duncan, Andrew R, Erlank, Anthony J, Marsh, Julian S
- Authors: Duncan, Andrew R , Erlank, Anthony J , Marsh, Julian S
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/134154 , vital:37079 , https://inis.iaea.org/search/searchsinglerecord.aspx?recordsFor=SingleRecordamp;RN=15001076
- Description: The extrusive and intrusive rocks of the Karoo Igneous Province are dominantly of basaltic or rhyolitic (sensu lato) composition. There are, however, a considerable variety of other rock types within the province including picritic basalts, nephelinites, shoshonites, latites, andesites and dacites. This paper deals with the geochemistry of the Karoo igneous province.
- Full Text:
- Date Issued: 1984
- Authors: Duncan, Andrew R , Erlank, Anthony J , Marsh, Julian S
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/134154 , vital:37079 , https://inis.iaea.org/search/searchsinglerecord.aspx?recordsFor=SingleRecordamp;RN=15001076
- Description: The extrusive and intrusive rocks of the Karoo Igneous Province are dominantly of basaltic or rhyolitic (sensu lato) composition. There are, however, a considerable variety of other rock types within the province including picritic basalts, nephelinites, shoshonites, latites, andesites and dacites. This paper deals with the geochemistry of the Karoo igneous province.
- Full Text:
- Date Issued: 1984
The petrogenesis of the Kirwan Basalts of Dronning Maud Land, Antarctica
- Harris, Chris, Marsh, Julian S, Duncan, Andrew R, Erlank, Anthony J
- Authors: Harris, Chris , Marsh, Julian S , Duncan, Andrew R , Erlank, Anthony J
- Date: 1990
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145472 , vital:38441 , https://doi.org/10.1093/petrology/31.2.341
- Description: The 420 m thick sequence of Kirwan basalt crops out along the southernmost 50 km of the Kirwanveggen Escarpment (74°S, 6°W). There is little variation in major element chemistry of these basalts (SiO2 49·3–51·6 wt.%; MgO 5·1–6·6 wt.%), but the concentrations of certain incompatible elements (e.g., Zr) vary by factors of approximately two or more.
- Full Text: false
- Date Issued: 1990
- Authors: Harris, Chris , Marsh, Julian S , Duncan, Andrew R , Erlank, Anthony J
- Date: 1990
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145472 , vital:38441 , https://doi.org/10.1093/petrology/31.2.341
- Description: The 420 m thick sequence of Kirwan basalt crops out along the southernmost 50 km of the Kirwanveggen Escarpment (74°S, 6°W). There is little variation in major element chemistry of these basalts (SiO2 49·3–51·6 wt.%; MgO 5·1–6·6 wt.%), but the concentrations of certain incompatible elements (e.g., Zr) vary by factors of approximately two or more.
- Full Text: false
- Date Issued: 1990
The petrogenesis of the Kirwan Basalts of Dronning Maud Land, Antarctica
- Harris, Chris, Marsh, Julian S, Duncan, Andrew R, Erlank, Anthony J
- Authors: Harris, Chris , Marsh, Julian S , Duncan, Andrew R , Erlank, Anthony J
- Date: 1990
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145492 , vital:38443 , https://doi.org/10.1093/petrology/31.2.341
- Description: The 420 m thick sequence of Kirwan basalt crops out along the southernmost 50 km of the Kirwanveggen Escarpment (74°S, 6°W). There is little variation in major element chemistry of these basalts (SiO2 49·3–51·6 wt.%; MgO 5·1–6·6 wt.%), but the concentrations of certain incompatible elements (e.g., Zr) vary by factors of approximately two or more.
- Full Text: false
- Date Issued: 1990
- Authors: Harris, Chris , Marsh, Julian S , Duncan, Andrew R , Erlank, Anthony J
- Date: 1990
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145492 , vital:38443 , https://doi.org/10.1093/petrology/31.2.341
- Description: The 420 m thick sequence of Kirwan basalt crops out along the southernmost 50 km of the Kirwanveggen Escarpment (74°S, 6°W). There is little variation in major element chemistry of these basalts (SiO2 49·3–51·6 wt.%; MgO 5·1–6·6 wt.%), but the concentrations of certain incompatible elements (e.g., Zr) vary by factors of approximately two or more.
- Full Text: false
- Date Issued: 1990
Geochemistry and petrogenesis of the Etendeka volcanic rocks from SWA Namibia
- Erlank, Anthony J, Marsh, Julian S, Duncan, Andrew R, Miller, R M, Hawkesworth, C J, Betton, P J, Rex, D C
- Authors: Erlank, Anthony J , Marsh, Julian S , Duncan, Andrew R , Miller, R M , Hawkesworth, C J , Betton, P J , Rex, D C
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/133923 , vital:37041 , https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetailamp;idt=6519919
- Description: The volcanic rocks of the Etendeka Formation from north-west SWA/Namibia have a present-day coverage of 70,000 km² and comprise a series of interbedded basalts, latites and quartz latites, together with four varieties of intrusive dolerite. Apart from one group of dolerites (regional dolerites) which have mineralogical and geochemical similarities to the Lesotho Formation lavas from the Central area, the Etendeka volcanics differ from all other Karoo volcanics by virtue of their Cretaceous age, stratigraphy, mineralogy, geochemistry, and range in mineralogical, elemental and isotopic compositions for the basaltic rocks.
- Full Text:
- Date Issued: 1984
- Authors: Erlank, Anthony J , Marsh, Julian S , Duncan, Andrew R , Miller, R M , Hawkesworth, C J , Betton, P J , Rex, D C
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/133923 , vital:37041 , https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetailamp;idt=6519919
- Description: The volcanic rocks of the Etendeka Formation from north-west SWA/Namibia have a present-day coverage of 70,000 km² and comprise a series of interbedded basalts, latites and quartz latites, together with four varieties of intrusive dolerite. Apart from one group of dolerites (regional dolerites) which have mineralogical and geochemical similarities to the Lesotho Formation lavas from the Central area, the Etendeka volcanics differ from all other Karoo volcanics by virtue of their Cretaceous age, stratigraphy, mineralogy, geochemistry, and range in mineralogical, elemental and isotopic compositions for the basaltic rocks.
- Full Text:
- Date Issued: 1984
The role of continental lithosphere in the generation of the Karoo volcanic rocks: evidence from combined Nd-and Sr-isotope studies
- Hawkesworth, C J, Marsh, Julian S, Duncan, Andrew R, Erlank, Anthony J, Norry, M J
- Authors: Hawkesworth, C J , Marsh, Julian S , Duncan, Andrew R , Erlank, Anthony J , Norry, M J
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/134165 , vital:37080 , https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetailamp;idt=6453596
- Description: 143Nd/144Nd, 87Sr/86Sr, Sm and Nd analyses are reported on suites of Karoo volcanic rocks from the four sub-areas of Nuanetsi-north Lebombo, south Lebombo, the Central area, and north-west SWA/Namibia. Only seven (12%) of the samples analysed have positive ENd values similar to those found in the majority of recent mantle-derived rocks. Most of the rest have negative ENd (-1.0 to -17.1) and positive ESr, (+3.0 to +240) and thus must contain at least a contribution from source areas which were both old, and had lower Sm/Nd and higher Rh/Sr ratios than the bulk earth.
- Full Text:
- Date Issued: 1984
- Authors: Hawkesworth, C J , Marsh, Julian S , Duncan, Andrew R , Erlank, Anthony J , Norry, M J
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/134165 , vital:37080 , https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetailamp;idt=6453596
- Description: 143Nd/144Nd, 87Sr/86Sr, Sm and Nd analyses are reported on suites of Karoo volcanic rocks from the four sub-areas of Nuanetsi-north Lebombo, south Lebombo, the Central area, and north-west SWA/Namibia. Only seven (12%) of the samples analysed have positive ENd values similar to those found in the majority of recent mantle-derived rocks. Most of the rest have negative ENd (-1.0 to -17.1) and positive ESr, (+3.0 to +240) and thus must contain at least a contribution from source areas which were both old, and had lower Sm/Nd and higher Rh/Sr ratios than the bulk earth.
- Full Text:
- Date Issued: 1984
Strontium isotope characterization of Karoo volcanic rocks
- Bristow, J W, Allsopp, H L, Erlank, Anthony J, Marsh, Julian S, Armstrong, R A
- Authors: Bristow, J W , Allsopp, H L , Erlank, Anthony J , Marsh, Julian S , Armstrong, R A
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/134176 , vital:37081 , https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetailamp;idt=6453595
- Description: Karoo volcanics of both mafic and felsic composition cover large areas of southern Africa, and are characterized by considerable ranges in their initial 87Sr/86Sr (i.e. Ro) ratios. Mafic volcanics from the eastern and western continental margins show the greatest range in Ro ratios, i.e. Lebombo-Nuanetsi area: 0.7035-0.7134 and Etendeka: 0.7030-0.7135 respectively. In the Central Karoo area the mafic rocks show a smaller spread of ratios: 0.7046-0.7094.
- Full Text:
- Date Issued: 1984
- Authors: Bristow, J W , Allsopp, H L , Erlank, Anthony J , Marsh, Julian S , Armstrong, R A
- Date: 1984
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/134176 , vital:37081 , https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetailamp;idt=6453595
- Description: Karoo volcanics of both mafic and felsic composition cover large areas of southern Africa, and are characterized by considerable ranges in their initial 87Sr/86Sr (i.e. Ro) ratios. Mafic volcanics from the eastern and western continental margins show the greatest range in Ro ratios, i.e. Lebombo-Nuanetsi area: 0.7035-0.7134 and Etendeka: 0.7030-0.7135 respectively. In the Central Karoo area the mafic rocks show a smaller spread of ratios: 0.7046-0.7094.
- Full Text:
- Date Issued: 1984
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
- Date Issued: 1989
- 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
- Date Issued: 1989
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