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
A laterally extensive geochemical discontinuity in the subcontinental Gondwana Lithosphere
- Erlank, Anthony J, Duncan, Andrew R, Marsh, Julian S, Sweeney, R J, Hawkesworth, C J, Milner, Simon C, Miller, R McG, Rogers, N W
- Authors: Erlank, Anthony J , Duncan, Andrew R , Marsh, Julian S , Sweeney, R J , Hawkesworth, C J , Milner, Simon C , Miller, R McG , Rogers, N W
- Date: 1988
- Language: English
- Type: text , abstracts
- Identifier: http://hdl.handle.net/10962/131678 , vital:36710
- Description: Cox et al. (1967) first delineated the existence of two major geochemical provinces in the Karoo basalts of southern Africa. Tholeiitic basalts in Zimbabwe are highly enriched in incompatible trace elements and constitute the "northern province". In contrast, basalts from Lesotho and from the southern segment of the Lebombo monocline have lower or “normal” abundances of these elements and were regarded as a "southern province'. Recent work has established that this change in composition takes place relatively rapidly in the Central Lebombo.
- Full Text:
- Date Issued: 1988
- Authors: Erlank, Anthony J , Duncan, Andrew R , Marsh, Julian S , Sweeney, R J , Hawkesworth, C J , Milner, Simon C , Miller, R McG , Rogers, N W
- Date: 1988
- Language: English
- Type: text , abstracts
- Identifier: http://hdl.handle.net/10962/131678 , vital:36710
- Description: Cox et al. (1967) first delineated the existence of two major geochemical provinces in the Karoo basalts of southern Africa. Tholeiitic basalts in Zimbabwe are highly enriched in incompatible trace elements and constitute the "northern province". In contrast, basalts from Lesotho and from the southern segment of the Lebombo monocline have lower or “normal” abundances of these elements and were regarded as a "southern province'. Recent work has established that this change in composition takes place relatively rapidly in the Central Lebombo.
- Full Text:
- Date Issued: 1988
Distribution and petrogenesis of the basic rocks of the Etendeka Formation of northwestern Namibia
- Marsh, Julian S, Duncan, Andrew R, Milner, Simon C, Erlank, Anthony J
- Authors: Marsh, Julian S , Duncan, Andrew R , Milner, Simon C , Erlank, Anthony J
- Date: 1988
- Language: English
- Type: text , abstracts
- Identifier: http://hdl.handle.net/10962/131667 , vital:36709
- Description: The igneous rocks which comprise the Etendeka Formation in northwestern Namibia cover an area of 78 000 km² and consist dominantly of interbedded basalts and quartz latites, with minor latites. They are spatially associated with, and intruded by, two suites of dolerites. The rocks of the Etendeka Formation are included in the Karoo Igneous Province but differ from most other Karoo volcanics with respect to their younger age (Cretaceous) and aspects of their mineralogy and geochemistry.
- Full Text:
- Date Issued: 1988
- Authors: Marsh, Julian S , Duncan, Andrew R , Milner, Simon C , Erlank, Anthony J
- Date: 1988
- Language: English
- Type: text , abstracts
- Identifier: http://hdl.handle.net/10962/131667 , vital:36709
- Description: The igneous rocks which comprise the Etendeka Formation in northwestern Namibia cover an area of 78 000 km² and consist dominantly of interbedded basalts and quartz latites, with minor latites. They are spatially associated with, and intruded by, two suites of dolerites. The rocks of the Etendeka Formation are included in the Karoo Igneous Province but differ from most other Karoo volcanics with respect to their younger age (Cretaceous) and aspects of their mineralogy and geochemistry.
- Full Text:
- Date Issued: 1988
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