Multiple volcanic episodes of flood basalts caused by thermochemical mantle plumes
نویسندگان
چکیده
منابع مشابه
Dynamics of thermochemical plumes: 2. Complexity of plume structures and its implications for mapping mantle plumes
[1] The mantle plume hypothesis provides explanations for several major observations of surface volcanism. The dynamics of plumes with purely thermal origin has been well established, but our understanding of the role of compositional variations in the Earth’s mantle on plume formation is still incomplete. In this study we explore the structures of plumes originating from a thermochemical bound...
متن کاملUnderstanding cratonic flood basalts
The origin of continental flood basalts has been debated for decades. These eruptions often produce millions of cubic kilometers of basalt on timescales of only a million years. Although flood basalts are found in a variety of settings, no locale is more puzzling than cratonic areas such as southern Africa or the Siberian craton, where strong, thick lithosphere is breached by these large basalt...
متن کاملSiberian Flood Basalts
techniques and fractionation correcting to a 194Pt/ 95pt ratio of 0.9734 (38). 33. E. Anders and N. Grevesse, Geochim. Cosmochim. Acta 53, 197(1989). 34. M. P. Gorton, E. S. Schandl, A. J. Naldrett, Ocean Drilling Project Scientific Results, Leg 140, in press. 35. R. J. Walker et al., Geochim. Cosmochim. Acta 58, 4179 (1994); M. F. Horan, R. J. Walker, V. A. Fedorenko, G. K. Czamanske, ibid., i...
متن کاملThe influence of thermochemical convection on the fixity of mantle plumes
A general feature of both isochemical and thermochemical studies of mantle convection is that horizontal plume velocities tend to be smaller than typical convective velocities, however, it is not clear which system leads to a greater fixity of mantle plumes. We perform twoand three-dimensional numerical calculations and compare both thermochemical and isochemical cases with similar convective v...
متن کاملFlood basalts and hot-spot tracks: plume heads and tails.
Continental flood basalt eruptions have resulted in sudden and massive accumulations of basaltic lavas in excess of any contemporary volcanic processes. The largest flood basalt events mark the earliest volcanic activity of many major hot spots, which are thought to result from deep mantle plumes. The relative volumes of melt and eruption rates of flood basalts and hot spots as well as their te...
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ژورنال
عنوان ژورنال: Nature
سال: 2005
ISSN: 0028-0836,1476-4687
DOI: 10.1038/nature03697