منابع مشابه
Early Crustal Evolution of Mars1
■ Abstract The bulk of the ∼50-km-thick Martian crust formed at ∼4.5 Gyr B.P., perhaps from a magma ocean. This crust is probably a basaltic andesite or andesite and is enriched in incompatible and heat-producing elements. Later additions of denser basalt to the crust were volumetrically minor, but resurfaced significant portions of the Northern hemisphere. A significant fraction of the total t...
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The East African Orogen (EAO) is one of Earth’s great collision zones, where East and West Gondwana collided to form the supercontinent ‘Greater Gondwana’ or ‘Pannotia’ at the end of Neoproterozoic time. There is now sufficient Nd isotopic data for basement rocks of the EAO to yield a useful summary. A total of 449 samples were gleaned from the literature, recalculated to a common value for the...
متن کاملSouthern African crustal evolution and composition: Constraints from receiver function studies
[1] Stacking of approximately 1500 radial receiver functions recorded at about 80 broadband seismic stations deployed in southern Africa reveals systematic spatial variations in the ratio of crustal P and S wave velocities (F), crustal thickness (H), and the amplitude of the converted Moho phases (R). The eastern Zimbabwe and the southern Kaapvaal cratons are characterized by small H ( 38 km), ...
متن کاملThermal and crustal evolution of Mars
[1] We present a coupled thermal-magmatic model for the evolution of Mars’ mantle and crust that may be consistent with estimates of the average crustal thickness and crustal growth rate. By coupling a simple parameterized model of mantle convection to a batchmelting model for peridotite, we can investigate potential conditions and evolutionary paths of the crust and mantle in a coupled thermal...
متن کاملPan-African Tsetse and Trypanosomosis Eradication
20 In view of gathering baseline information about the prevalence of animal trypanosomosis, 21 the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) funded a cross 22 sectional survey in the Region of the Boucle du Mouhoun which constitutes the Northern 23 limit of the tsetse distribution in Burkina. This cross sectional study was carried out in 53 24 villages located in the ...
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ژورنال
عنوان ژورنال: Episodes
سال: 1980
ISSN: 0705-3797,2586-1298
DOI: 10.18814/epiiugs/1980/v3i2/001