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东南极拉斯曼丘陵晚元古代（１０００Ｍａ）高级变质杂岩中区域性产出一套粗粒柱晶紫苏堇青麻粒岩，其原岩为含硼的富镁铝泥质岩。岩石中结晶粗大的堇青石在矿物化学成分上属于镁堇青石，其成分显示不均匀且具较明显成分环带的特征，从核部到边缘，其ＸＭｇ（Ｍｇ／Ｍｇ＋Ｆｅ２＋）比值由０．８５５变化为０．８１６。温压计算结果表明，所研究堇青石形成的Ｐ－Ｔ条件约为０．７６～０．７２ＧＰａ和８６０℃～８３０℃（核部至边缘）。Ｘ－射线粉晶结构分析证明这种堇青石属于低位结构状态的堇青石，晶体结构扭曲指数Δ＝０．２８～０．３０，在自然界比较少见。实验室合成的低位结构状态的堇青石只在持续较长时间的１３００℃～１４００℃的高温条件下稳定存在。因此，这意味着低位堇青石可能是由很高温变质作用及缓慢冷却的条件下结晶形成，这对于研究该区的地壳演化具有极其重要的意义。
In the Late Proterozoic (1000 Ma) high-grade metamorphic complex of the Rastman Hills, East Antarctica, a set of coarse-grained columnar basil violet plexiglass granulite was produced. The original rock is boron-rich magnesian-aluminum argillaceous rock. The coarse crystalline cordierite in the rocks belongs to magnesia-cordierite in its mineralogical composition, and its composition is not uniform and has a more pronounced zoning. The XMg (Mg / Mg + Fe2 +) ratio from the core to the edge ranges from 0.855 Changed to 0.816. The results of the temperature and pressure calculation show that the P-T conditions of cordierite formation are about 0.76 ~ 0.72GPa and 860 ℃ ~ 830 ℃ (core-to-edge). X-ray powder crystal structure analysis shows that this cordierite belongs to the low-level structure of cordierite, the crystal structure distortion index Δ = 0.28 ~ 0.30, relatively rare in nature. The low-structure cordierite synthesized in the laboratory was stable only under the high temperature of 1300 ℃ ~ 1400 ℃ for a long time. Therefore, this means that the lower cordierite may be crystallized under the conditions of very high temperature metamorphism and slow cooling, which is extremely important for studying the crustal evolution in this area.