Age of Fault Movements in Tanzanian Sector of East African Rift System

Macintyre, R. M.; Mitchell, J. G.; Dawson, J. B.

doi:10.1038/247354a0

Cited by 74 publications

(41 citation statements)

References 5 publications

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“…Nevertheless, this age suggests that the beginning of volcanic activity for Shira at around 2.5 Ma is synchronous to others magmatic centres of the NKVB further W (Ngorongoro and Monduli-Meru areas, see Fig. 1) (Macintyre et al, 1974;Dawson, 1992).…”

Section: The Shira Stagementioning

confidence: 99%

“…The arrangement of dated volcanic features in the NTD into tectono-magmatic lineaments supplies additional insights on its structural history during the onset of magmatism. The compilation of existing radiochronological ages (Evernden and Curtis, 1965;Evans et al, 1971;Bagdasaryan et al, 1973;MacIntyre et al, 1974, Wilkinson et al,1986, Dawson, 1992) reveal a rough E-W age progression which is due to a shift of magmatic activity eastwards in the time range 5.0 Ma-Present. The precursor volcanics in the NTD are nephelinites, ~8.1-7.3 Ma in age, emplaced in the Essimingor region (Bagdasaryan et al, 1973), but the main volcanic activity started at 5.0 Ma and involved three successive magmatic stages until recent times.…”

Section: Tectono-magmatic Rift Frameworkmentioning

confidence: 99%

“…To the W, magmatism waned markedly at the SW extremity of the Eyasi belt whereas new eruptive centres were emplaced further NE (Olmoti) up to the intersection with the Magadi NS axis (Manega, 1993 ;Foster et al, 1997). In the Essimingor central domain, ongoing volcanism shifted eastwards along the NE-SW-trending Tarosero axis, as well as in the Engaruka and Ketumbeine areas (Bagdasaryan et al, 1973;MacIntyre et al, 1974).…”

Section: Tectono-magmatic Rift Frameworkmentioning

confidence: 99%

“…The 50 x 200 km NKVB comprises numerous volcanic edifices, and their extensively distributed effusive and air-fall material, that were emplaced during the time interval 8 MaPresent (Evernden and Curtis, 1965;Evans et al, 1971;Bagdasaryan et al, 1973;Macintyre et al, 1974, Wilkinson et al,1986, Dawson, 1992 close to, or following in part, a fundamental lithospheric-scale discontinuity between Proterozoic terranes of the Mozambique Belt and Archaean cratonic blocks involving the Masai nucleus (Fig. 1).…”

Section: Tectono-magmatic Rift Frameworkmentioning

confidence: 99%

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New K–Ar age determinations of Kilimanjaro volcano in the North Tanzanian diverging rift, East Africa

Nonnotte

Guillou

Gall

et al. 2008

Journal of Volcanology and Geothermal Research

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The Kilimanjaro is the African highest mountain and culminates at 5895 m high. This huge volcanic edifice is composed of three main centres along a N110°E-striking axis (Shira, Kibo and Mawenzi from W to E), and emplaced in a key area where a major N80°E-oriented volcanic lineament intersects a first-order NW-SE basement fault-like discontinuity.Seventeen K-Ar ages (on microcrystalline groundmass) acquired on lavas and intrusive facies from the three eruptive centres confirm that the Plio-Quaternary volcanicity of Kilimanjaro is clearly polyphased. The oldest phases of volcanic activity begun at ~2.5 Ma in the Shira vent and our data suggest that the latest important phases occurred around 1.9 Ma, just before the collapse of the Northern part of the edifice. Magmatic activity then shifted eastwards in the

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Section: The Shira Stagementioning

confidence: 99%

Section: Tectono-magmatic Rift Frameworkmentioning

confidence: 99%

Section: Tectono-magmatic Rift Frameworkmentioning

confidence: 99%

Section: Tectono-magmatic Rift Frameworkmentioning

confidence: 99%

See 2 more Smart Citations

New K–Ar age determinations of Kilimanjaro volcano in the North Tanzanian diverging rift, East Africa

Nonnotte

Guillou

Gall

et al. 2008

Journal of Volcanology and Geothermal Research

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“…This Eastern branch of the EARS has a relative elevation of ~500 m above the basin floor and is the surface expression of the major ManyaraNatron Fault (Macintyre et al, 1974).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Morphotectonic interpretation of the Makuyuni catchment in Northern Tanzania using DEM and SAR data

et al. 2015

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Varying styles of magmatic strain accommodation across the East African Rift

Muirhead

Kattenhorn

Corvec

2015

Geochem Geophys Geosyst

115

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Observations of active dike intrusions provide present day snapshots of the magmatic contribution to continental rifting. However, unravelling the contributions of upper crustal dikes over the timescale of continental rift evolution is a significant challenge. To address this issue, we analyzed the morphologies and alignments of >1500 volcanic cones to infer the distribution and trends of upper crustal dikes in various rift basins across the East African Rift (EAR). Cone lineament data reveal along-axis variations in the distribution and geometries of dike intrusions as a result of changing tectonomagmatic conditions. In younger (<10 Ma) basins of the North Tanzanian Divergence, dikes are largely restricted to zones of rift-oblique faulting between major rift segments, referred to here as transfer zones. Cone lineament trends are highly variable, resulting from the interplay between (1) the regional stress field, (2) local magma-induced stress fields, and (3) stress rotations related to mechanical interactions between rift segments. We find similar cone lineament trends in transfer zones in the western branch of the EAR, such as the Virunga Province, Democratic Republic of the Congo. The distributions and orientations of upper crustal dikes in the eastern branch of the EAR vary during continental rift evolution. In early-stage rifts (<10 Ma), upper crustal dikes play a limited role in accommodating extension, as they are confined to areas in and around transfer zones. In evolved rift basins (>10 Ma) in Ethiopia and the Kenya Rift, rift-parallel dikes accommodate upper crustal extension along the full length of the basin.

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Age of Fault Movements in Tanzanian Sector of East African Rift System

Cited by 74 publications

References 5 publications

New K–Ar age determinations of Kilimanjaro volcano in the North Tanzanian diverging rift, East Africa

New K–Ar age determinations of Kilimanjaro volcano in the North Tanzanian diverging rift, East Africa

Morphotectonic interpretation of the Makuyuni catchment in Northern Tanzania using DEM and SAR data

Varying styles of magmatic strain accommodation across the East African Rift

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