https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 The oxygen isotope composition of Karoo and Etendeka picrites: High δ18O mantle or crustal contamination? https://vital.seals.ac.za/vital/access/manager/Repository/vital:27829 Wed 27 Sep 2023 08:48:19 SAST ]]> The geochemistry and evolution of Palaeogene phonolites, central Namibia: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38399 Wed 12 May 2021 23:49:34 SAST ]]> Magma flow inferred from AMS fabrics in a layered mafic sill, Insizwa, South Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:6733 1000-m-thick layered mafic intrusion, part of the Karoo Igneous Province in South Africa. The peridotitic and gabbronoritic rocks are undeformed and mineral fabrics demonstrably result from magma flow. A horizontal, centimeter-scale model layering is visible in numerous outcrops. Plagioclase crystals are both tabular and elongated. Their preferred orientation, parallel to the layering, forms a foliation and a NW–SE lineation, respectively interpreted as the magma flow plane and flow direction. Throughout the 78 stations of this study (699 specimens), magnetic susceptibilities (K[subscript m]) range from 750 to 10,000×10[superscript (−6)] SI. The magnetic anisotropy (P[subscript j]) ranges from 1.03 to 1.08. Magnetic ellipsoids are both prolate and oblate (average T[subscript j]≈0). Anisotropy of magnetic susceptibility (AMS) fabrics are dominated by multidomain to pseudo-single domain magnetite. High-field magnetic experiments indicate that the paramagnetic contribution from the mafic silicates is less than 50 percentage for low susceptibility rock types. The anisotropy results from magnetite grain shape solely as shown by no significant increase in P[subscript j] with increasing K[subscript m]. The magnetic lineation (305°, 05°) is consistent throughout the sill at various scales and coincides with the mineral lineation in average. In contrast, the magnetic foliation (125° NE 10°) is generally perpendicular to the mineral foliation and to the layering. Several explanations for this odd configuration are discussed. The variations of magnetic parameters across the layering and field observations point to a multiple injection. The magnetic lineation is consistent with the presence of a single feeder dike situated to the SE of the sill.]]> Wed 12 May 2021 23:40:31 SAST ]]> Excursion to Granitberg and the Klinghardt Mountains, southern Namibia https://vital.seals.ac.za/vital/access/manager/Repository/vital:36801 Wed 12 May 2021 23:27:36 SAST ]]> Distribution and petrogenesis of the basic rocks of the Etendeka Formation of northwestern Namibia https://vital.seals.ac.za/vital/access/manager/Repository/vital:36709 Wed 12 May 2021 23:21:07 SAST ]]> Tertiary phonolite volcanism in the Klinghardt Mountains of South West Africa/Namibia https://vital.seals.ac.za/vital/access/manager/Repository/vital:36953 Wed 12 May 2021 23:19:45 SAST ]]> Review of South African research on volcanic and related rocks and mantle-derived materials : 1999-2002 https://vital.seals.ac.za/vital/access/manager/Repository/vital:6737 Wed 12 May 2021 23:04:24 SAST ]]> Karoo basalts of the Springbok Flats: geochemistry and correlation https://vital.seals.ac.za/vital/access/manager/Repository/vital:36706 Wed 12 May 2021 22:46:08 SAST ]]> High-Mg tholeiitic rocks and their significance in the Karroo Central Province https://vital.seals.ac.za/vital/access/manager/Repository/vital:36916 Wed 12 May 2021 22:23:29 SAST ]]> The Lüderitz alkaline province, South West Africa, III: the Pomona and Drachenberg Syenite Complexes https://vital.seals.ac.za/vital/access/manager/Repository/vital:36915 Wed 12 May 2021 21:06:34 SAST ]]> Rock magnetic stratigraphy of a mafic layered sill: a key to the Karoo volcanics plumbing system https://vital.seals.ac.za/vital/access/manager/Repository/vital:38389 Wed 12 May 2021 21:01:09 SAST ]]> The late Archaean Dominion Group, South Africa: petrogenesis of flood-type basalts and their mantle sources https://vital.seals.ac.za/vital/access/manager/Repository/vital:36721 Wed 12 May 2021 20:53:14 SAST ]]> Volcanic rocks of the Witwatersrand triad, South Africa I: description, classification and geochemical stratigraphy https://vital.seals.ac.za/vital/access/manager/Repository/vital:37663 Wed 12 May 2021 20:26:49 SAST ]]> Report on the Mesozoic volcanic and intrusive rocks on the Namibe Basin, Southwest Angola: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38384 Wed 12 May 2021 20:14:27 SAST ]]> The role of continental lithosphere in the generation of the Karoo volcanic rocks: evidence from combined Nd-and Sr-isotope studies https://vital.seals.ac.za/vital/access/manager/Repository/vital:37080 Wed 12 May 2021 19:45:41 SAST ]]> Field Trip A1: Karoo dykes, sills and volcanics in the Eastern Cape https://vital.seals.ac.za/vital/access/manager/Repository/vital:38383 Wed 12 May 2021 19:35:30 SAST ]]> Karoo volcanic and intrusive rocks: Lesotho and Eastern Cape https://vital.seals.ac.za/vital/access/manager/Repository/vital:38388 Wed 12 May 2021 19:33:48 SAST ]]> Petrology and geochemistry of early cretaceous bimodal continental flood volcanism of the NW Etendeka, Namibia Part 2: characteristics and petrogenesis of the high-Ti latite and high-Ti and low-Ti voluminous quartz latite eruptives https://vital.seals.ac.za/vital/access/manager/Repository/vital:38987 Wed 12 May 2021 19:32:41 SAST ]]> MORB-related dolerites associated with the final phases of Karoo flood basalt volcanism in southern Africa. https://vital.seals.ac.za/vital/access/manager/Repository/vital:38222 Wed 12 May 2021 19:28:50 SAST ]]> Petrogenesis of late Archaean flood-type basic lavas from the Klipriviersberg Group, Ventersdorp Supergroup, South Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:38470 Wed 12 May 2021 19:28:43 SAST ]]> The geochemistry of potassic lavas from Vulsini, central Italy and implications for mantle enrichment processes beneath the Roman region https://vital.seals.ac.za/vital/access/manager/Repository/vital:37330 Wed 12 May 2021 19:18:10 SAST ]]> Geochemical constraints on coupled assimilation and fractional crystallization involving upper crustal compositions and continental tholeiitic magma https://vital.seals.ac.za/vital/access/manager/Repository/vital:37888 Wed 12 May 2021 19:04:21 SAST ]]> The largest volcanic eruptions on Earth https://vital.seals.ac.za/vital/access/manager/Repository/vital:36902 1000 km3 dense rock equivalent) and large-magnitude (> M8) eruptions produce really extensive (104–105 km2) basaltic lava flow fields and silicic ignimbrites that are the main building blocks of LIPs.]]> Wed 12 May 2021 19:04:07 SAST ]]> Stratigraphic correlation of the Awahab and Tafelberg Formations, Etendeka Group, Namibia, and location of an eruptive site for flood basalt volcanism https://vital.seals.ac.za/vital/access/manager/Repository/vital:6738 Wed 12 May 2021 18:38:07 SAST ]]> An attempt to constrain the age, duration, and eruptive history of the Karoo flood basalt: Naude's Nek section (South Africa) https://vital.seals.ac.za/vital/access/manager/Repository/vital:38401 Wed 12 May 2021 18:30:54 SAST ]]> Distribution of Ca in highly fractionated peralkaline magmas https://vital.seals.ac.za/vital/access/manager/Repository/vital:36914 Wed 12 May 2021 18:21:07 SAST ]]> Geology Field Trip Guide: Natural Sciences and Geography Educators visit https://vital.seals.ac.za/vital/access/manager/Repository/vital:38387 Wed 12 May 2021 18:20:14 SAST ]]> Evolution of a strongly differentiated suite of phonolites from the Klinghardt Mountains, Namibia https://vital.seals.ac.za/vital/access/manager/Repository/vital:37885 Wed 12 May 2021 18:18:30 SAST ]]> Dyke swarms and associated lava formations in the northern Lebombo monocline, Karoo Large Igneous Province, South Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:36880 Wed 12 May 2021 18:16:40 SAST ]]> Volcanic rocks of the Witwatersrand Triad, South Africa. II: petrogenesis of mafic and felsic rocks of the Dominion Group https://vital.seals.ac.za/vital/access/manager/Repository/vital:37889 Wed 12 May 2021 18:02:16 SAST ]]> The chemistry and petrogenesis of igneous rocks of the Karoo central area, southern Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:37042 Wed 12 May 2021 17:58:03 SAST ]]> Regional geochemistry of the Karoo igneous province https://vital.seals.ac.za/vital/access/manager/Repository/vital:37079 Wed 12 May 2021 17:41:49 SAST ]]> The Etendeka Igneous Province: magma types and their stratigraphic distribution with implications for the evolution of the Paraná-Etendeka flood basalt province https://vital.seals.ac.za/vital/access/manager/Repository/vital:38882 Wed 12 May 2021 17:32:37 SAST ]]> Rare earth element geochemistry of the Insizwa lobe of the Mount Ayliff Complex, Eastern Cape, South Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:6736 Wed 12 May 2021 17:25:33 SAST ]]> Basalt geochemistry and tectonic discrimination within continental flood basalt provinces https://vital.seals.ac.za/vital/access/manager/Repository/vital:37886 Wed 12 May 2021 17:07:12 SAST ]]> Cretaceous volcanic rocks of the Namibe Basin, southern Angola: report on a reconnaissance field and geochemical investigation https://vital.seals.ac.za/vital/access/manager/Repository/vital:29070 Wed 12 May 2021 16:51:26 SAST ]]> Base-metal mineralization in alkaline pyroclastics: the Regenstein Vent, South West Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:36950 Wed 12 May 2021 16:48:46 SAST ]]> Evolution of the continental lithosphere: evidence from volcanics and xenoliths in southern Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:36989 Wed 12 May 2021 16:46:50 SAST ]]> A laterally extensive geochemical discontinuity in the subcontinental Gondwana Lithosphere https://vital.seals.ac.za/vital/access/manager/Repository/vital:36710 Wed 12 May 2021 16:46:40 SAST ]]> The Karoo igneous province: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38413 Wed 12 May 2021 16:25:40 SAST ]]> Stratigraphy and age of Karoo basalts of Lesotho and implications for correlations within the Karoo igneous province https://vital.seals.ac.za/vital/access/manager/Repository/vital:38859 Wed 12 May 2021 16:21:58 SAST ]]> Emplacement of inflated Pāhoehoe flows in the Naude’s Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement https://vital.seals.ac.za/vital/access/manager/Repository/vital:27826 Wed 12 May 2021 16:05:48 SAST ]]> The Bero Volcanic Complex: extension of the Paraná-Etendeka Igneous Province into SW Angola https://vital.seals.ac.za/vital/access/manager/Repository/vital:27827 Tue 18 Jul 2023 23:02:02 SAST ]]> Petrology and geochemistry of peridotite xenoliths from the Letlhakane kimberlites, Botswana https://vital.seals.ac.za/vital/access/manager/Repository/vital:38876 Tue 18 Jul 2023 22:48:00 SAST ]]> Alkaline rocks in the Kuboos-Bremen Igneous Province, southern Namibia: the Grootpenseiland and Marinkas Kwela Complexes https://vital.seals.ac.za/vital/access/manager/Repository/vital:38471 Tue 18 Jul 2023 22:34:02 SAST ]]> The Marinkas Quellen Carbonatite Complex, southern Namibia: carbonatite magmatism with an uncontaminated depleted mantle signature in a continental setting https://vital.seals.ac.za/vital/access/manager/Repository/vital:38879 Tue 18 Jul 2023 22:34:01 SAST ]]> The petrology and significance of a stratiform mafic segregation pegmatite in a Karoo-aged dolerite sheet https://vital.seals.ac.za/vital/access/manager/Repository/vital:38858 Tue 10 Aug 2021 12:45:36 SAST ]]> Significance of 87Sr/86Sr ratios in the Merensky cyclic unit of the Bushveld Complex https://vital.seals.ac.za/vital/access/manager/Repository/vital:36986 Tue 10 Aug 2021 12:45:35 SAST ]]> Some geochemical constraints upon models for the crystallization of the upper critical zone-main zone interval, northwestern Bushveld complex https://vital.seals.ac.za/vital/access/manager/Repository/vital:37331 Tue 10 Aug 2021 12:45:35 SAST ]]> The mineralogy, petrology, and origin of the Merensky cyclic unit in the western Bushveld Complex https://vital.seals.ac.za/vital/access/manager/Repository/vital:37329 Tue 10 Aug 2021 12:45:35 SAST ]]> Cretaceous erosion in central South Africa: evidence from upper-crustal xenoliths in kimberlite diatremes https://vital.seals.ac.za/vital/access/manager/Repository/vital:38397 Tue 06 Jul 2021 09:22:41 SAST ]]> Tying up the continents https://vital.seals.ac.za/vital/access/manager/Repository/vital:38220 Thu 13 May 2021 16:44:15 SAST ]]> Sub-volcanic intrusions and the link to global climatic and environmental changes: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38414 Thu 13 May 2021 15:42:37 SAST ]]> Oxygen isotope geochemistry of the Mesozoic volcanics of the Etendeka Formation, Namibia https://vital.seals.ac.za/vital/access/manager/Repository/vital:38219 Thu 13 May 2021 13:39:03 SAST ]]> Supplying lava eruptions in the Karoo Province, South Africa: a geochemical comparison of the volcanic sequence with intrusions in the main Karoo basin https://vital.seals.ac.za/vital/access/manager/Repository/vital:36901 Thu 13 May 2021 12:25:57 SAST ]]> The geochemical structure of the Insizwa lobe of the Mount Ayliff complex with implications for the emplacement and evolution of the complex and its Ni-sulphide potential https://vital.seals.ac.za/vital/access/manager/Repository/vital:38984 Thu 13 May 2021 11:56:23 SAST ]]> The emplacement of class 1 kimberlites: part 2, petrographic evidence https://vital.seals.ac.za/vital/access/manager/Repository/vital:36878 Thu 13 May 2021 08:52:52 SAST ]]> Geochemical stratigraphy of the Mohale Dame-Katse Dam areas, Lesotho. Report on contract LHDA, Mohale Tunnel: Sampling and Testing of Cores. Lesotho Highlands Tunnel Partnership (Mohale) https://vital.seals.ac.za/vital/access/manager/Repository/vital:38385 Thu 13 May 2021 08:48:11 SAST ]]> Eruptive history of the Karoo lava flows and their impact on early Jurassic environmental change: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38408 Thu 13 May 2021 08:21:02 SAST ]]> The concentrations of the noble metals in Southern African flood-type basalts and MORB: implications for petrogenesis and magmatic sulphide exploration https://vital.seals.ac.za/vital/access/manager/Repository/vital:38985 Thu 13 May 2021 07:38:14 SAST ]]> The petrogenesis of the Kirwan Basalts of Dronning Maud Land, Antarctica https://vital.seals.ac.za/vital/access/manager/Repository/vital:38441 Thu 13 May 2021 07:36:39 SAST ]]> Geochemical variations in a long Karoo dyke, Eastern Cape https://vital.seals.ac.za/vital/access/manager/Repository/vital:38877 Thu 13 May 2021 07:30:22 SAST ]]> The Luderitz Alkaline Province, South West Africa I: descriptive petrology of the Granitberg Foyaite Complex https://vital.seals.ac.za/vital/access/manager/Repository/vital:36912 Thu 13 May 2021 07:28:37 SAST ]]> Implications of a new 40Ar/ 39Ar age for a basalt flow interbedded with the Etjo Formation, Northeast Namibia https://vital.seals.ac.za/vital/access/manager/Repository/vital:38970 Thu 13 May 2021 06:56:08 SAST ]]> The Karoo igneous province: an introduction https://vital.seals.ac.za/vital/access/manager/Repository/vital:37043 Thu 13 May 2021 06:53:34 SAST ]]> Geochemistry and petrogenesis of the Etendeka volcanic rocks from SWA Namibia https://vital.seals.ac.za/vital/access/manager/Repository/vital:37041 Thu 13 May 2021 05:59:43 SAST ]]> New views on the Jurassic Clarens Formation: volcano-sedimentary interaction https://vital.seals.ac.za/vital/access/manager/Repository/vital:36874 Thu 13 May 2021 05:56:33 SAST ]]> Promotion of the Etendeka Formation to Group status: a new integrated stratigraphy https://vital.seals.ac.za/vital/access/manager/Repository/vital:38442 Thu 13 May 2021 05:47:55 SAST ]]> Distinct kimberlite pipe classes with contrasting eruption processes https://vital.seals.ac.za/vital/access/manager/Repository/vital:38988 Thu 13 May 2021 05:25:52 SAST ]]> The Luderitz Alkaline Province, South West Africa II: metasomatism and assimilation in the contact aureole of the Granitberg Foyaite Complex https://vital.seals.ac.za/vital/access/manager/Repository/vital:36913 Thu 13 May 2021 05:06:53 SAST ]]> Al/Cr ratios of coexisting pyroxenes and spinellids in some ultramafic rocks https://vital.seals.ac.za/vital/access/manager/Repository/vital:36987 Thu 13 May 2021 04:47:40 SAST ]]> New chemical analyses of the Suurberg volcanic rocks and their significance in relation to Mesozoic volcanism in Southern Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:36951 Thu 13 May 2021 04:34:38 SAST ]]> The Dominion Group: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38412 Thu 13 May 2021 04:21:07 SAST ]]> Preliminary geochemical data for dolerite dykes and sills of the southern part of the Etendeka Igneous Province https://vital.seals.ac.za/vital/access/manager/Repository/vital:36803 Thu 13 May 2021 04:12:53 SAST ]]> Compositionally diverse magmas erupted close together in space and time within a Karoo flood basalt crater complex: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38396 40 km2 filled by 9–18 km3 of volcaniclastic debris.]]> Thu 13 May 2021 03:42:14 SAST ]]> The emplacement of class 1 kimberlites: part 1, evidence of geological features https://vital.seals.ac.za/vital/access/manager/Repository/vital:36877 Thu 13 May 2021 03:31:00 SAST ]]> Petrology of the alkaline core of the Messum igneous complex, Namibia: evidence for the progressively decreasing effect of crustal contamination https://vital.seals.ac.za/vital/access/manager/Repository/vital:38880 Thu 13 May 2021 02:06:50 SAST ]]> Karoo basalts, South Africa: Petrogenesis and the nature of their mantle rocks https://vital.seals.ac.za/vital/access/manager/Repository/vital:29625 Thu 13 May 2021 01:28:06 SAST ]]> The distribution of platinum group elements in the Insizwa lobe, Mount Ayliff Complex, South Africa: implications for Ni-Cu-PGE sulfide exploration in the Karoo igneous province https://vital.seals.ac.za/vital/access/manager/Repository/vital:38969 Thu 13 May 2021 01:26:37 SAST ]]> Petrology and geochemistry of Early Cretaceous bimodal continental flood volcanism of the NW Etendeka, Namibia Part 1: introduction, mafic lavas and re-evaluation of mantle source components https://vital.seals.ac.za/vital/access/manager/Repository/vital:38986 Thu 13 May 2021 01:16:02 SAST ]]> The petrogenesis of the Kirwan Basalts of Dronning Maud Land, Antarctica https://vital.seals.ac.za/vital/access/manager/Repository/vital:38443 Thu 13 May 2021 01:15:36 SAST ]]> Re-estimation of erosion levels in Group I and II kimberlites between Lesotho, Kimberley and Victoria West, South Africa https://vital.seals.ac.za/vital/access/manager/Repository/vital:36804 Thu 13 May 2021 01:11:41 SAST ]]> REE fractionation and Ce anomalies in weathered Karoo dolerite https://vital.seals.ac.za/vital/access/manager/Repository/vital:38469 Thu 13 May 2021 00:14:05 SAST ]]> Karoo dolerite intrusions: shaping the landscapes of the Great Karoo https://vital.seals.ac.za/vital/access/manager/Repository/vital:38409 Thu 13 May 2021 00:07:18 SAST ]]> Strontium isotope characterization of Karoo volcanic rocks https://vital.seals.ac.za/vital/access/manager/Repository/vital:37081 Thu 13 May 2021 00:00:04 SAST ]]> Karoo and Etendeks flood basalt provinces, southern Africa and the tectonic development of their adjacent margins: https://vital.seals.ac.za/vital/access/manager/Repository/vital:38386 Fri 09 Feb 2024 15:54:52 SAST ]]>