Volcanism associated with the onset of Karoo flood basalt eruptions (c. 180 Ma) at Sterkspruit, South Africa, began with emplacement of thin lava flows before abruptly switching to phreatomagmatic and magmatic activity that formed a nest of craters, spatter and tuff rings and cones that collectively comprise a crater complex >40 km� filled by 9-18 km� of volcaniclastic debris. Phreatomagmatic activity driven by interaction of Karoo magma with groundwater hosted in country rock and crater-filling debris quarried broad, mainly shallow craters (hundreds of metres, but not kilometers deep) into wall-rock. Closely spaced individual vents, the consequence of magma emplaced over a broad area through a network of feeder dikes and stocks, were active at the same time or over short periods of time. Highly ephemeral access of external water to vents drove repeated and reversible switches between explosive to effusive magmatic and explosive phreatomagmatic activity, resulting in vents and craters that grew laterally and vertically into adjacent ones through quarrying and vent migration. Deposits within the Sterkspruit crater complex are dominated by 7-15 km� of massive, unsorted polymict lapilli tuff and tuff breccia juxtaposed with localised fountain-fed lava and strombolian spatter deposits. Transport within the complex was dominated by jets and fountains of volcaniclastic debris and by mass movement. Country-rock breccias indicate that craters grew via a combination of mechanical fragmentation, granulation and mass-movement of 7-12 km� of wall-rock, adding mass and previously locked-up pore-water to the volcanic system. Ash and lapilli, the deposits of plumes 5-15 km high, form a 50-110 m-thick ejecta blanket mantling Clarens Formation country rock that thins gradually away from the crater-complex margins. Explosive volcanism was succeeded by brief fluvial and eolian reworking of volcaniclastic debris and formation of a shallow crater lake 12 km� in extent, and then by voluminous effusion of flood basalt that inundated the Sterkspruit crater complex with lava. Flood basalt magmas involved in Sterkspruit eruptions were chemically heterogenous. This study documents the rapid (perhaps simultaneous) eruption of multiple, chemically distinct basaltic magmas, which cannot be simply related to one another, from one vent site, and possibly many others, within the Sterkspruit crater complex. Five distinct magma types were involved in eruptions at Sterkspruit, indicating that in the early stages of flood basalt eruption (i) magma batches may be small and not simply related to one another, (ii) heterogeneities in the magma source region may be close to each other in time and space, and (iii) eruptions of chemically distinct magmas may take place over short intervals of space and time without significant hybridisation. Formation of the Sterkspruit Complex, and many others like it in South Africa, confirms that the opening phases of Karoo flood basalt volcanism were explosive, and that the volume of the products of explosive volcanism may have important implications for climate change and landscape development associated with the emplacement of large igneous provinces.

Volcanism associated with the onset of Karoo flood basalt eruptions (c. 180 Ma) at Sterkspruit, South Africa, began with emplacement of thin lava flows before abruptly switching to phreatomagmatic and magmatic activity that formed a nest of craters, spatter and tuff rings and cones that collectively comprise a crater complex >40 km� filled by 9-18 km� of volcaniclastic debris. Phreatomagmatic activity driven by interaction of Karoo magma with groundwater hosted in country rock and crater-filling debris quarried broad, mainly shallow craters (hundreds of metres, but not kilometers deep) into wall-rock. Closely spaced individual vents, the consequence of magma emplaced over a broad area through a network of feeder dikes and stocks, were active at the same time or over short periods of time. Highly ephemeral access of external water to vents drove repeated and reversible switches between explosive to effusive magmatic and explosive phreatomagmatic activity, resulting in vents and craters that grew laterally and vertically into adjacent ones through quarrying and vent migration. Deposits within the Sterkspruit crater complex are dominated by 7-15 km� of massive, unsorted polymict lapilli tuff and tuff breccia juxtaposed with localised fountain-fed lava and strombolian spatter deposits. Transport within the complex was dominated by jets and fountains of volcaniclastic debris and by mass movement. Country-rock breccias indicate that craters grew via a combination of mechanical fragmentation, granulation and mass-movement of 7-12 km� of wall-rock, adding mass and previously locked-up pore-water to the volcanic system. Ash and lapilli, the deposits of plumes 5-15 km high, form a 50-110 m-thick ejecta blanket mantling Clarens Formation country rock that thins gradually away from the crater-complex margins. Explosive volcanism was succeeded by brief fluvial and eolian reworking of volcaniclastic debris and formation of a shallow crater lake 12 km� in extent, and then by voluminous effusion of flood basalt that inundated the Sterkspruit crater complex with lava. Flood basalt magmas involved in Sterkspruit eruptions were chemically heterogenous. This study documents the rapid (perhaps simultaneous) eruption of multiple, chemically distinct basaltic magmas, which cannot be simply related to one another, from one vent site, and possibly many others, within the Sterkspruit crater complex. Five distinct magma types were involved in eruptions at Sterkspruit, indicating that in the early stages of flood basalt eruption (i) magma batches may be small and not simply related to one another, (ii) heterogeneities in the magma source region may be close to each other in time and space, and (iii) eruptions of chemically distinct magmas may take place over short intervals of space and time without significant hybridisation. Formation of the Sterkspruit Complex, and many others like it in South Africa, confirms that the opening phases of Karoo flood basalt volcanism were explosive, and that the volume of the products of explosive volcanism may have important implications for climate change and landscape development associated with the emplacement of large igneous provinces.

Bibliography: pages 360-378 / In this study, the researcher investigates an HIV and AIDS prevention programme known as Education for Life (EFLP) run by the Roman Catholic Church (RCC). The programme seeks to encourage behaviour changes as a viable approach for the prevention of HIV and AIDS through education. EFLP is faith-based and run by the RCC as one of the programmes in RCC pastoral mission activities to mitigating the HIV and AIDS epidemic. EFLP aims at preventing HIV and AIDs through creating awareness of human values in the context of the gospel, facts about HIV and AIDs and promoting behaviour change, particularly among the youth. The programme is youth-led, peer-driven and peer support based. The researcher examines EFLP in Sterkspruit Parish from 2003 to 2013 to assess whether EFLP was effective in bringing about preventative sexual behaviour, as a result of participants in the programme changing attitudes and values and acquiring life skills. RCC and many Christian churches promote behavioural intervention abstinence, fidelity within marriage, counselling and delaying sexual debut and partner reduction. Behavioural change programmes have, however, not been without controversies. A qualitative research method was followed to investigate the impact of EFLP. Data were obtained and tape-recorded during one-on-one interviews of 25 youth participants. The researcher employed the theory of reasoned action to examine the data. Analysis of data revealed that the mission of the church could be achieved through social transformation in the lives of the youth, especially behavioural change concerning HIV and AIDS. It also showed that a single preventative approach should not be taken to the exclusion of others in the prevention of HIV and AIDs. The study recommends combining different approaches, including promoting behavioural change / Christian Spirituality, Church History and Missiology / Ph. D. (Missiology)