Outcrops of East Antarctic Shield exposed along the coast of Princess Elizabeth Land (PEL) provide a peek into its Neoproterozoic evolution. The terrain comprises of interleaved pelitic, felsic and mafic granulites. Examination of mafic granulites from Sostrene Islands - Larsemann Hills - Brattstrand Bluffs terrain indicate multiple sources for their protolith. The ensemble of mafic rocks intimately associated with sedimentary protoliths are sourced from older mafic crust as well as syn-sedimentary intrusives, prior to multiple stages of deformation and high-grade metamorphism, often including felsic melt generation. High-grade metamorphism (peak conditions of ~900 °C and 11 kbar) followed by two stages of decompression, which are indicated by the presence of symplectitic growth of orthopyroxene over garnet and in cracks in garnetiferous mafic granulite. Pseudosection modelling confirms that the mafic granulites underwent a near isothermal decompression of ~2–3 kbar, indicating a clockwise PT path. Chemical dating of monazites from associated paragneisses show three growth zones viz. a Grenvillian aged core (884–940 Ma) followed by a thin Upper Tonian- Cryogenian aged middle rim (689–754 Ma) and a typical Pan African aged outer rim (523 Ma). We suggest that the thermo-tectonic evolution of PEL outcrops should be reassessed taking into account the newly emerging evidence of Tonian metamorphism.

沿着伊丽莎白公主地 (PEL) 海岸暴露的东南极地盾的露头提供了对其新元古代演化的一瞥。地形包括交错的泥质、长英质和镁铁质麻粒岩。对来自 Sostrene Islands - Larsemann Hills - Brattstrand Bluffs 地形的镁铁质麻粒岩的检查表明它们的原岩有多种来源。与沉积原岩密切相关的镁铁质岩石集合来自较旧的镁铁质地壳以及同沉积侵入岩，在多阶段变形和高等级变质作用之前，通常包括长英质熔体的生成。高级变质作用（峰值条件约 900 °C 和 11 kbar），然后是两个减压阶段，这通过在石榴石上和石榴石镁铁质麻粒岩的裂缝中存在斜方辉石的辛生长来表明。伪剖面模型证实镁铁质麻粒岩经历了约 2-3 kbar 的近等温减压，表明顺时针 PT 路径。来自相关副片麻岩的独居石的化学测年显示了三个生长区，即。一个 Grenvillian 老化核心（884-940 Ma），然后是一个薄的上托尼安 - Cryogenian 老化中环（689-754 Ma）和一个典型的泛非老化外环（523 Ma）。我们建议考虑到托尼安变质作用的新出现的证据，重新评估 PEL 露头的热构造演化。来自相关副片麻岩的独居石的化学测年显示了三个生长区，即。一个 Grenvillian 老化核心（884-940 Ma），然后是一个薄的上托尼安 - Cryogenian 老化中环（689-754 Ma）和一个典型的泛非老化外环（523 Ma）。我们建议考虑到托尼安变质作用的新出现的证据，重新评估 PEL 露头的热构造演化。来自相关副片麻岩的独居石的化学测年显示了三个生长区，即。一个 Grenvillian 老化核心（884-940 Ma），然后是一个薄的上托尼安 - Cryogenian 老化中环（689-754 Ma）和一个典型的泛非老化外环（523 Ma）。我们建议考虑到托尼安变质作用的新出现的证据，重新评估 PEL 露头的热构造演化。