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安大略西北部Schryburt湖碳酸岩杂岩体的一套不含长英质、富含云母的碱性超镁铁质岩内,铈铌钙钛矿和Ba-Fe锰钡矿与钙钛矿密切共生。围岩中主要为各种不同含量的Mg-橄榄石、金云母、磁铁矿、钛铁矿、磷灰石和碳酸盐(通常为方解石),其次为少量的镁次透辉石。因此,它们相当于Rock(1990)所指的超镁铁质煌班岩(即方解霞黄煌岩),或Mitchell(1993)所指的黄长岩类的煌斑岩相。杂岩体中的钙钛矿是主要的钛酸盐矿物,晶粒呈自形和他形,后者的边缘有熔蚀现象。主要由于轻稀土元素、Na和Nb含量的变化,使钙钛矿呈复杂的带状构造。根据矿物命名原则,该矿物可细分为钙钛矿和铈钙钛矿,铈铌钙钛矿呈小的自形晶附生于受熔蚀的钙钛矿核上。从化学成分上看,铈铌钙钛矿、斜方钠铌矿和钙钛矿实际上是属于同一固溶体系列的矿物。由此,它们又可分为钙质铈铌钙钛矿、铌钙铈铌钙钛矿、钙铌铈铌钙钛矿、铈铌钙钛矿和铌质铈铌钙钛矿。锰钡矿族的钛酸盐是稀有副矿物,它们的成分非常接近于层状钛酸盐BaFe~(2+)Ti_7O_(16)的化学成分。钙钛矿颗粒的复杂分带是其在结晶阶段富含稀土元素、Na和Nb成分的碳酸盐岩流体周期性侵入硅酸盐体系的结果。早期生成的钙钛矿与富含氟(F)的流体的连续作用导致局部环境富含Ti、Na、Nb和稀土,它们来自流体相和不稳定的钙钛矿。随后铈铌钙钛矿从这种特殊的化学环境中结晶出来。
In the Schryburt Lake carbonate complex in northwestern Ontario, a suite of alkaline mafic-rich ultrabasic mafic rocks, Ce-Nb perovskites and Ba-Fe Mn-Ba coexists closely with perovskite. The surrounding rocks are mainly Mg-olivine, phlogopite, magnetite, ilmenite, apatite and carbonate (usually calcite), followed by a small amount of magnesium diopside. Therefore, they are equivalent to the mafic brontite (referred to as Fangxu Xiahuanguang rock) within the meaning of Rock (1990), or the lamprophyre facies of the feldspar type denoted by Mitchell (1993). Perovskite in the complex is the main titanate mineral, the grains are self-shaped and the shape of his, the latter edge of the erosion phenomenon. Mainly due to the light rare earth elements, Na and Nb content changes, the perovskite complex ribbon structure. According to the principle of nomenclature, the mineral can be subdivided into perovskite and cerium perovskite. Cerium-niobium perovskite is small in shape attached to the corroded perovskite core. From a chemical point of view, ceric niobium perovskite, orthoclase niobium ore and perovskite are actually belong to the same solid solution series of minerals. As a result, they are subdivided into calcareous cerium-niobium perovskites, niobium-cesium-cerium-niobium perovskites, calcium-niobium-cerium-niobium perovskites, cerium-niobium perovskites and niobium-cerium-niobium perovskites. Manganese barium titanate is a rare accessory minerals, their composition is very close to the layered titanate BaFe ~ (2 +) Ti_7O_ (16) of the chemical composition. The complex zoning of perovskite particles is a result of the periodic infiltration of carbonate fluids containing rare earth elements and Na and Nb into the silicate system during the crystallization stage. The continuous action of earlier-formed perovskite and fluorine-rich (F) fluids results in the local environment being enriched in Ti, Na, Nb and rare earths, both from the fluid phase and from unstable perovskites. Cerium-niobium perovskites subsequently crystallize out of this particular chemical environment.