【摘 要】
：
The Purang ophiolite is a large mantle peridotite massif ca.600 km2 in area.The mantle peridotite is composed dominantly of harzburgite,lherzolite and minor dunite.The Fo and NiO contents of olivine i
【机 构】
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Institute of Earth Sciences,China University of Geosciences,Wuhan 430074,China;State Key Laboratory
【出 处】
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International Workshop on: Ophiolites, Mantle Processes and
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The Purang ophiolite is a large mantle peridotite massif ca.600 km2 in area.The mantle peridotite is composed dominantly of harzburgite,lherzolite and minor dunite.The Fo and NiO contents of olivine in the peridotites are in the range of 89.5-92.8 and 0.23-0.44 wt.％,respectively; both of these parameters increase gradually from lherzolite to harzburgite.The orthopyroxene porphyroblasts are enstatite(En=85.1-90.1),with Mg＃s of 87.6 to 92.0 and Al2O3 contents of 0.9 to 5.2 wt.％,whereas the clinopyroxenes are endiopside and diopside with low Al2O3(1.2-6.0 wt.and high Mg＃s(89.5-94.5).Spinels in the lherzolites have much lower C＃s(18.5-31.5)than those in the harzburgites(25.0-71.7),but all of the spinels have very low Ti contents(max.0.1 wt.％).The modal mineralogy and mineral compositions change both gradually and abruptly across the ophiolite,within and between the various lithologies,indicating a complex origin for the body.
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