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米仓山地区发现一种自然界较为少见的与超基性岩有关的富镁钙质矽卡岩。矽卡岩产于晋宁中期超基性岩与中元古代大理岩接触带上 ,并被晋宁晚期中基性浅成侵入体肢解和包裹。与一般产于中酸性侵入体与石灰岩接触带的钙质矽卡岩不同的是除了含有大量透辉石、钙铝—钙铁榴石、硅灰石、符山石等钙质矽卡岩常见矿物外 ,还普遍发育有钙镁橄榄石、金云母富镁硅酸盐矿物 ;岩石中缺乏长石、石英、金属硫化物及其他热液阶段矿物 ,所有这些特征在很大程度上与超基性岩浆的富镁、贫硅、缺少挥发组分的性质有关。
Micangshan area found a rare in nature and ultrabasic rocks related to magnesium-rich calcareous skarn. Skarn was produced on the contact zone of metaphysic rocks and Mesoproterozoic marble in the middle of Jinning and was dismembered and wrapped by the medium-basic shallow intrusions in the late Jinning. Unlike calcareous skarn, which is generally found in the acidic intrusive and limestone contact zones, in addition to the common minerals of calcareous skarn containing large amounts of diopside, calcareous-dacite, wollastonite, In addition, there are also generally developed calcium-forsterite and phlogopite-rich magnesia silicate minerals; feldspar, quartz, metal sulphides and other hydrothermal stages of minerals are absent from the rock, all of which are largely related to ultrabasic Magnesium-rich magnesium, poor silicon, the lack of volatile components of the nature.