With remarkable force,"decolonization"re-entered the academic agenda some ten years ago.Having been an ambivalent historical experience undergirding postcolonial studies in its emergence in the 1980s,"d...With remarkable force,"decolonization"re-entered the academic agenda some ten years ago.Having been an ambivalent historical experience undergirding postcolonial studies in its emergence in the 1980s,"decolonization"today is wielded as a concept and a rallying call.One of its rhetorical purposes is to set up an opposition between morally objectionable and morally progressive ways of constructing and sharing knowledge,yet the content of the term is often vague.In this context,world literature has much to contribute,both methodologically and critically.If,on the one hand,there is a decolonizing potential in the very ambition to make the world's literary cultures visible,the critical dimension of world literature scholarship makes us aware of its colonial genealogy.Taking Mazisi Kunene's epic poem from South Africa,Emperor Shaka the Great,as its key example,this article discusses how the dual potential of world literature might contribute to a"decolonized"'mode of literary reading.展开更多
Over the past two decades, a significant number of discoveries of ancient zircon xenocrysts in ocean-floor magmatic rocks have been reported. These findings provide compelling evidence for the presence of ancient cont...Over the past two decades, a significant number of discoveries of ancient zircon xenocrysts in ocean-floor magmatic rocks have been reported. These findings provide compelling evidence for the presence of ancient continental crust within young oceanic lithosphere. Almost all finds of ancient zircon xenocrysts within oceanic crust are from the Mid-Atlantic Ridge. For other localities, however, similar data are very limited. This report presents the first age determinations(U-Pb, SHRIMPII) and isotope-geochemical data(oxygen, trace and rare earth elements) for zircon xenocrysts from gabbro-diorites of the Shaka Ridge, in the vicinity of the Shaka fracture zone, near the western end of the Southwest Indian Ridge. The work is based on a study of bottom rock material dredged during expeditionary research on the R/V"Akademik Fedorov"(Russia) in 2016. The U-Pb isotope system of the zircon xenocrysts recorded a crystallization age of ~2.8 Ga at an upper discordia intercept and an age of ~600 Ma interpreted as the timing of a superimposed thermal event at a lower discordia intercept.The zircon xenocrysts show geochemical signatures of magmatic origin, i.e., fractionated REE distribution spectra with an increase in chondrite-normalized values from light to heavy REE, positive Ce anomalies and negative Eu anomalies, and high Th/U ratios(0.59-7.77). In discrimination diagrams based on a series of inter-element relationships, zircon compositions fall into the fields of zircons from rocks of continental crust, mostly granitoids. The Li content of the zircons is high(1.8 ppm-50 ppm),adding further evidence to their derivation from rocks of continental crust. During their residence within young oceanic crust, the zircon xenocrysts experienced alterations under the influence of submarine high-temperature hydrothermal fluids, which selectively affected the distribution of trace elements in the zircons and reduced the δ;O values to 1.75‰-3.15‰. The presence of obviously older zircons in Shaka gabbro-diorites clearly demonstrat展开更多
文摘With remarkable force,"decolonization"re-entered the academic agenda some ten years ago.Having been an ambivalent historical experience undergirding postcolonial studies in its emergence in the 1980s,"decolonization"today is wielded as a concept and a rallying call.One of its rhetorical purposes is to set up an opposition between morally objectionable and morally progressive ways of constructing and sharing knowledge,yet the content of the term is often vague.In this context,world literature has much to contribute,both methodologically and critically.If,on the one hand,there is a decolonizing potential in the very ambition to make the world's literary cultures visible,the critical dimension of world literature scholarship makes us aware of its colonial genealogy.Taking Mazisi Kunene's epic poem from South Africa,Emperor Shaka the Great,as its key example,this article discusses how the dual potential of world literature might contribute to a"decolonized"'mode of literary reading.
基金funded by the National Key R & D Program of China(No.2016YFE0203000)the National Natural Science Foundation of China(No.41673018)+1 种基金conducted under state contract(Institute of Precambrian Geology and Geochronology of Russian Academy of Sciences)(No.FMNU-2022-0005)supported by the state assignment project of IGM SB RAS。
文摘Over the past two decades, a significant number of discoveries of ancient zircon xenocrysts in ocean-floor magmatic rocks have been reported. These findings provide compelling evidence for the presence of ancient continental crust within young oceanic lithosphere. Almost all finds of ancient zircon xenocrysts within oceanic crust are from the Mid-Atlantic Ridge. For other localities, however, similar data are very limited. This report presents the first age determinations(U-Pb, SHRIMPII) and isotope-geochemical data(oxygen, trace and rare earth elements) for zircon xenocrysts from gabbro-diorites of the Shaka Ridge, in the vicinity of the Shaka fracture zone, near the western end of the Southwest Indian Ridge. The work is based on a study of bottom rock material dredged during expeditionary research on the R/V"Akademik Fedorov"(Russia) in 2016. The U-Pb isotope system of the zircon xenocrysts recorded a crystallization age of ~2.8 Ga at an upper discordia intercept and an age of ~600 Ma interpreted as the timing of a superimposed thermal event at a lower discordia intercept.The zircon xenocrysts show geochemical signatures of magmatic origin, i.e., fractionated REE distribution spectra with an increase in chondrite-normalized values from light to heavy REE, positive Ce anomalies and negative Eu anomalies, and high Th/U ratios(0.59-7.77). In discrimination diagrams based on a series of inter-element relationships, zircon compositions fall into the fields of zircons from rocks of continental crust, mostly granitoids. The Li content of the zircons is high(1.8 ppm-50 ppm),adding further evidence to their derivation from rocks of continental crust. During their residence within young oceanic crust, the zircon xenocrysts experienced alterations under the influence of submarine high-temperature hydrothermal fluids, which selectively affected the distribution of trace elements in the zircons and reduced the δ;O values to 1.75‰-3.15‰. The presence of obviously older zircons in Shaka gabbro-diorites clearly demonstrat
