Spinels from the Dawros Peridotite, Connemara, Ireland
نویسنده
چکیده
TWO different spinels, analyses of which are given, occur in the layered ultramafic rocks at Dawros. Chrome spinel occurs both as gravity-stratified cumulates and as complex orbs, while an Al-rich spinel is both in rocks of the main Dawros magmatic sequence and in an association with an aluminous bronzite, which may originate by recrystallization. It is concluded that while the chrome spinel is certainly of magmatic origin, the aluminous spinel is probably partly of magmatic and partly of reerystallization origin.
منابع مشابه
بررسی شیمی اسپینل و الیوین و تعیین محیط زمین ساختی پریدوتیت‌های افیولیت شمال‌غرب پیرانشهر، شمال‌غرب ایران
According to the olivine and spinel chemistry, two types of peridotite were identified from west north Piranshahr ophiolite. Peridotite rocks are classified based on chemistry of spinel and olivine. Average number of Cr in spinels (Cr#[(100*Cr/(Cr+Al))]) and Mg-number (Mg#[100*Mg/(Mg+Fe)]) in dunite are 0.63 and 0.51 respectively. In harzburgite, Cr# is 0.33 and Mg# is 0.67 and in spinel from s...
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The study area forms part of the Zagros Zone. It is located on the NW of Piranshahr town, NW Iran. The study of altered peridotite clasts of the Creteceous conglomerate is the main subject of this research. They have polygenetic origins having calcite as the constituent cement. The size of clast is ranging from mm to cm including sedimentary and metamorphic rocks fragments, altered peridotites ...
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