منابع مشابه
Peridotites Related to 4vesta: Deep Crustal Igneous Cumulates and Mantle
In advance of the arrival of the DAWN spacecraft at 4Vesta in 2011, it is useful to reassess our knowledge of the constitution and probable evolution of this ancient differentiated asteroid. It has been recognized for some time that the eucrite, diogenite and howardite meteorites likely represent samples from 4Vesta or from related Vestoids based upon the good match of reflectance spectra of th...
متن کاملComments on Some Misconceptions in Igneous and Experimental Petrology and Methodology: a Reply
rate’ of cpx and opx. Isobaric melting experiments show INTRODUCTION a > b, but the abyssal peridotite data suggest b > a, i.e. I recently showed (Niu, 1997) that proportions of residual opx would contribute more than cpx to the melt during minerals in abyssal peridotites (e.g. Dick, 1989; Johnson melting beneath ocean ridges. As abyssal peridotites et al., 1990; Johnson & Dick, 1992) exhibit s...
متن کاملPetrology of the igneous rocks in the west and southwest of Razan, Hamedan Province
West and southwest of Razan igneous rocks are located in the Hamedan Province in the Sanandaj- Sirjan zone, west Iran. According to petrography and chemical studies, these rock bodies are composed of diorite, gabbrodiorite, monzonite, quartz- monzonite, andesite and andesibasalt. The results of geochemical analysis show that these rocks belong to a cal- alkaline magma series. The geochemical c...
متن کاملCooling of the Earth in the Archaean: Consequences of pressure-release melting in a hotter mantle
A model is presented to describe the cooling of the Earth in the Archaean. At the higher Archaean mantle temperatures pressure-release melting starts deeper and generates a thicker basaltic or komatiitic crust and depleted harzburgite layer compared with the present-day situation. Intrinsic compositional stability and lack of mechanical coherency renders the mechanism of plate tectonics ineffec...
متن کاملMagma in a Beaker: Analog Experiments with Water and Various Salts or Sugar for Teaching Igneous Petrology
Solutions of water and a salt or sugar make excellent experimental analog magmas for teaching concepts of igneous petrology because of the comparatively low temperatures involved, the simplicity of the apparatus needed, and the responsiveness of familiar chemical systems. Boiling of these aqueous solutions on a hot plate can be used to increase the concentration of a dissolved salt or sugar to ...
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ژورنال
عنوان ژورنال: Nature
سال: 1986
ISSN: 0028-0836,1476-4687
DOI: 10.1038/320306a0