@article{oai:nipr.repo.nii.ac.jp:00002413,
 author = {Johnston,Stephen T. and Armstrong,Richard and Heaman,Larry and McCourt,Steve and Mitchell,Andrew and Bisnath, Avi and Arima,Makoto},
 journal = {Memoirs of National Institute of Polar Research. Special issue},
 month = {Jul},
 note = {P(論文), We report on the preliminary results of a geochronological study of the Tugela terrane, the northernmost tectonic element of the Mesoproterozoic Natal belt of eastern South Africa. The Tugela terrane consists of a west-plunging structural stack, with the structurally highest, most allochthonous and presumably most oceanic tectonostratigraphic packages exposed to the west. Our study focused on the three highest tectonostratigraphic packages. These are, from west to east, the Tugela, Mandleni and Madidima, respectively. The Tugela tectonostratigraphic package consists of an oceanic arc sequence, including arc tholeiites and a tonalite intrusion (the Kotongweni tonalite gneiss). The Mandleni tectonostratigraphic package is characterized by a geochemically enriched bimodal magmatic succession (the Dondwana tectonite unit). Metasedimentary rocks comprise the Madidima tectonostratigraphic package, including the feldspathic Dulumbe paragneiss. All the thrust sheets are characterized by a penetrative schistosity/gneissosity, and by synkinematic upper amphibolite to granulite grade metamorphism. Voluminous mafic to ultramafic magmatism, including the emplacement of the Tugela Rand complex, the Mkondene diorite and the Mambula complex, which is characterized by massif anorthosite, occurred late during this tectonic event. Subsequent exhumation and lower amphibolite grade metamorphism was coeval with the development of north-verging folds and thrust faults, tectonic interleaving of the terrane with ophiolite, and voluminous granitic magmatism (the Wosi granitoid suite). U-Pb zircon age determinations constrain the age of the metasedimentary Dulumbe paragneiss to being post-1276±10Ma, the age of the oldest detrital component in the sequence. The lack of any older detrital zircons suggests that the Tugela terrane was far-removed from the Archaean Kaapvaal craton during deposition. Oceanic magmatic arc development was underway by 1209±5Ma, the age of the protolith of the Kotongweni tonalite gneiss. Subsequent crustal thickening and tectonic burial of the terrane occurred prior to about 1180Ma, the age of intrusion of the late to posttectonic Mkondene diorite and the Mambula complex. Peak metamorphism occurred at 1175±9Ma, the age of metamorphic zircon, and inherited zircons that had suffered syn-metamorphic Pb-loss in the Dulumbe paragneiss. Subsequent exhumation and northward obduction of the terrane, occurred at around 1155±1Ma, the age of syntectonic intrusions of the Wosi granitoid suite.},
 pages = {40--58},
 title = {Preliminary U-Pb geochronology of the Tugela terrane, Natal belt, eastern South Africa},
 volume = {55},
 year = {2001}
}