Advances in Earth Science ›› 2005, Vol. 20 ›› Issue (5): 525-532. doi: 10.11867/j.issn.1001-8166.2005.05.0525
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PENG Touping 1,2;WANG Yuejun 1;PENG Bingxia 1,2
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PENG Touping;WANG Yuejun;PENG Bingxia. THE SUMMARY ON A KIND OF RARE ROCK—FERROBASALTS/FERROPICRITES[J]. Advances in Earth Science, 2005, 20(5): 525-532.
High-Fe, magnesian rocks (Ferrobasalts/Ferropicrites) are characterized by high FeO* contents (tatal Fe as FeO*)(generally >14%), silica-poor, and low alkaline. These rocks belong to the tholeiitic-Ferropicritic series. The iron-rich and silica-poor liquids (the Fenner trend), commonly different from the low iron and silica-rich liquids (the Bowen trend), are rare on the earth surface. There are not the same, which can be used to explain their petrogenesis at present. Summing up the previous studies, the type of petrogenesis mainly include: (1) high degrees of partial melting of the dehydrated subducting slab or the overlying mantle wedge which has been metasomatized by the slab melt, at low pressure; (2) Simply crystal fractionation from common mid-ridge type basaltic magmas in closed or nearly closed system; (3) Partial melting of high-Fe magnesian melts from mantle plume starting-heads. The study on the mechanism of petrogenesis of high-Fe magnesian magmas is important to understand the tectonic regime of magmas in depth, early evolution of crust, the heterogeneity of lower mantle and the interaction of core-mantle. Meanwhile, it is also most significative for us to understand the petrogenesis of high-Fe magnesian rocks discovered from southern Taihang Mountains and other regions, in China.