The geochemistry of basic volcanics of the Dordabis Formation northeast of Dordabis and their significance for correlations within, and evolution of, the Rehoboth Magmatic Arc
- Marsh, Julian S, Williams-Jones, I E
- Authors: Marsh, Julian S , Williams-Jones, I E
- Date: 1985
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69763 , vital:29577 , http://www.mme.gov.na/files/publications/95f_Williams-Jones and Marsh_Dordabis Fm.pdf
- Description: Gevers (1934) named the succession of quartzites, feld-spathic sandstones, massive conglomeratic arkoses and sedimentary breccias around Dordabis, the Dordabis Series. He considered this series to be of Nama age and the basic volcanics in the series to be post Nama, pre-Karoo eruptive diabase. Schalk (pers. comm.) has found the succession to be pre-Damara in age and possibly equivalent to the Sinclair Sequence. These ‘Dordabis Series’ rocks have since been incorrectly included into the Marienhof Formation of the Rehoboth Sequence on the 1980 1:1 000 000 Geological Map of SWA/Namibia. In this report, it is suggested that this succession be called the Dordabis Formation.
- Full Text:
- Date Issued: 1985
- Authors: Marsh, Julian S , Williams-Jones, I E
- Date: 1985
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69763 , vital:29577 , http://www.mme.gov.na/files/publications/95f_Williams-Jones and Marsh_Dordabis Fm.pdf
- Description: Gevers (1934) named the succession of quartzites, feld-spathic sandstones, massive conglomeratic arkoses and sedimentary breccias around Dordabis, the Dordabis Series. He considered this series to be of Nama age and the basic volcanics in the series to be post Nama, pre-Karoo eruptive diabase. Schalk (pers. comm.) has found the succession to be pre-Damara in age and possibly equivalent to the Sinclair Sequence. These ‘Dordabis Series’ rocks have since been incorrectly included into the Marienhof Formation of the Rehoboth Sequence on the 1980 1:1 000 000 Geological Map of SWA/Namibia. In this report, it is suggested that this succession be called the Dordabis Formation.
- Full Text:
- Date Issued: 1985
The geochemistry of potassic lavas from Vulsini, central Italy and implications for mantle enrichment processes beneath the Roman region
- Rogers, N W, Hawkesworth, C J, Parker, R J, Marsh, Julian S
- Authors: Rogers, N W , Hawkesworth, C J , Parker, R J , Marsh, Julian S
- Date: 1985
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/136034 , vital:37330 , https://doi.org/10.1007/BF00378265
- Description: Major and trace element and 143Nd/144Nd (0.51209–0.51216) and 87Sr/86Sr (0.70879–0.71105) isotope analyses are presented on a representative group of lavas from the Vulsini district of the Roman magmatic province. Three distinct series are identified; the high-K and low-K series are similar to those described from other Italian volcanoes, while the third is represented by a group of relatively undifferentiated leucite basanites which are thought to be near-primary mantle melts.
- Full Text: false
- Date Issued: 1985
- Authors: Rogers, N W , Hawkesworth, C J , Parker, R J , Marsh, Julian S
- Date: 1985
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/136034 , vital:37330 , https://doi.org/10.1007/BF00378265
- Description: Major and trace element and 143Nd/144Nd (0.51209–0.51216) and 87Sr/86Sr (0.70879–0.71105) isotope analyses are presented on a representative group of lavas from the Vulsini district of the Roman magmatic province. Three distinct series are identified; the high-K and low-K series are similar to those described from other Italian volcanoes, while the third is represented by a group of relatively undifferentiated leucite basanites which are thought to be near-primary mantle melts.
- Full Text: false
- Date Issued: 1985
The mineralogy, petrology, and origin of the Merensky cyclic unit in the western Bushveld Complex
- Kruger, Floris J, Marsh, Julian S
- Authors: Kruger, Floris J , Marsh, Julian S
- Date: 1985
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/136024 , vital:37329 , https://doi.org/10.2113/gsecongeo.80.4.958
- Description: The Merensky cyclic unit of the Bushveld Complex represents the first products to crystallize after the influx and mixing of a large new batch of magma in the chamber. Excluding the Merensky pegmatoid, the Merensky cyclic unit grades upward from an orthopyroxenite at the base, through norite to anorthosite at the top of the sequence. It is followed by the very similar Bastard cyclic unit.
- Full Text: false
- Date Issued: 1985
- Authors: Kruger, Floris J , Marsh, Julian S
- Date: 1985
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/136024 , vital:37329 , https://doi.org/10.2113/gsecongeo.80.4.958
- Description: The Merensky cyclic unit of the Bushveld Complex represents the first products to crystallize after the influx and mixing of a large new batch of magma in the chamber. Excluding the Merensky pegmatoid, the Merensky cyclic unit grades upward from an orthopyroxenite at the base, through norite to anorthosite at the top of the sequence. It is followed by the very similar Bastard cyclic unit.
- Full Text: false
- Date Issued: 1985
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