Oxide and Cation Compositions of Olivine Grains from Drill Core in the Duluth Complex, Minnesota

The table contains oxide and cation compositions of olivine grains from drill core of the Duluth Complex, Minnesota. The oxides were determined by electron probe microanalysis (EPMA) and are reported in weight percent (wt%). The cations were calculated based on the oxide compositions and are reported in mole percent (mol%). Olivine is a magnesium iron orthosilicate mineral with the formula (Mg2+, Fe2+)2SiO4. Olivine forms a solid solution series with magnesium (Mg) at one end and iron (Fe) at the other. Forsterite (Mg2SiO4) is the magnesium endmember and fayalite (Fe2SiO4) is the iron endmember. Minor elements can substitute into the crystal structure, such as manganese (Mn) and nickel (Ni). To better understand the chemical composition of the measured olivine grains, the percent forsterite (Fo), also known as the magnesium number (Mg#), and the percent fayalite (Fa) were calculated.本数据集表格收录了取自美国明尼苏达州杜卢斯杂岩（Duluth Complex）钻孔岩心的橄榄石颗粒的氧化物与阳离子组成数据。其中氧化物组分通过电子探针显微分析（electron probe microanalysis, EPMA）测定，结果以重量百分比（weight percent, wt%）标注；阳离子组成则基于氧化物组分计算得到，结果以摩尔百分比（mole percent, mol%）标注。橄榄石是一种镁铁正硅酸盐矿物，化学式为(Mg²⁺, Fe²⁺)₂SiO₄。其构成以镁端员与铁端员为两端的固溶体系列：镁端员为镁橄榄石（Forsterite, Mg₂SiO₄），铁端员为铁橄榄石（Fayalite, Fe₂SiO₄）。少量微量元素（如锰Mn、镍Ni）可类质同像替代进入其晶体晶格。为更深入解析被测橄榄石颗粒的化学组成，研究人员计算了镁橄榄石百分含量（Fo，亦称镁指数magnesium number, Mg#）与铁橄榄石百分含量（Fa）。