The Yesilova ophiolite located in the Alpine zone. This work deals with differentiation mechanism of ultramafic cumulate in ophiolite. Generally, the sequence consists of gabbro and plagiogranite. The petrographic and...The Yesilova ophiolite located in the Alpine zone. This work deals with differentiation mechanism of ultramafic cumulate in ophiolite. Generally, the sequence consists of gabbro and plagiogranite. The petrographic and petrolgichal properties of it show that the layering in gabbros are products of a differentiation by fractional crystallization insitu. Because it has ferrous compounds （magnetite, hematite） by means of volatiles （H2O, CO2） that evidence magma at high temperatures （〉700 ℃）. Ferrous liquids are compatible with fractional crystallization through olivine, plagioclase, clinopyroxene removal; whereas the evolved gabbros represent clinopyroxene, plagioclase cumulates from ferrous liquids with little amounts of trapped melt. Furthermore, cathodo luminesans image of zircons shows chemichal characteristic of oceanic plagiogranit （such as Fe2O3/MgO, Rb, Sr, Zr, TiO2） that these characters can be explained by fractional crystallization processes in the late stage of magma generation. Furthermore, all plagiogranites have small positive Eu anomalies indicating the significant role of plagioclase in the fractional crystallization. So, the Yesilova ophiolite ultramafic cumulates are the most probably related to crystal-liquid fractionation process of the oceanic crust of the Alpine belt. The plagiogranite is differentiation products of crystal-liquid insitu ofa mafic magma in the magma chamber.展开更多
文摘The Yesilova ophiolite located in the Alpine zone. This work deals with differentiation mechanism of ultramafic cumulate in ophiolite. Generally, the sequence consists of gabbro and plagiogranite. The petrographic and petrolgichal properties of it show that the layering in gabbros are products of a differentiation by fractional crystallization insitu. Because it has ferrous compounds （magnetite, hematite） by means of volatiles （H2O, CO2） that evidence magma at high temperatures （〉700 ℃）. Ferrous liquids are compatible with fractional crystallization through olivine, plagioclase, clinopyroxene removal; whereas the evolved gabbros represent clinopyroxene, plagioclase cumulates from ferrous liquids with little amounts of trapped melt. Furthermore, cathodo luminesans image of zircons shows chemichal characteristic of oceanic plagiogranit （such as Fe2O3/MgO, Rb, Sr, Zr, TiO2） that these characters can be explained by fractional crystallization processes in the late stage of magma generation. Furthermore, all plagiogranites have small positive Eu anomalies indicating the significant role of plagioclase in the fractional crystallization. So, the Yesilova ophiolite ultramafic cumulates are the most probably related to crystal-liquid fractionation process of the oceanic crust of the Alpine belt. The plagiogranite is differentiation products of crystal-liquid insitu ofa mafic magma in the magma chamber.
