Princess Elizabeth Land (PEL) preserves an intricate amalgamation of complexly intersecting orogenic belts of the Gondwanian age cross cut by the ramified East Antarctic Rift system. Indo-Australo-Antarctic Suture (IAAS) is an extensive orogenic zone connecting the Africo-Antarctic domain of Dronning Maud Land to the Australo-Antarctic domain of Wilkes Land region through the Indo-Antarctic domain of Princess Elizabeth Land, touching the northern boundary of the Gamburtsev Subglacial Mountains (GSMs). The GSMs and IAAS, located in the interior of PEL, are completely hidden within the ice sheet. The connection between the IAAS and concealed GSMs remains ambiguous due to insufficient geological evidence. Marine sediments from Prydz Bay offer clues to explore this segment of PEL. In this work, sediments from Ocean Drilling Program (ODP) sites: 740, 742, and 739, representing proximal to relatively distal sites, respectively, were subjected to geochemical and zircon isotopic analyses to understand the crustal evolution of PEL, IAAS, and GSM. The sediment geochemistry indicates that sediments from site 740, being proximal, are immature, less recycled, and more chemically weathered as compared to sites 742 and 739. Discriminant plots of major and trace elements provide active and passive continental margin signatures. Site 739 and 742 sediments display the rift setting signatures while sediments of site 740 depict signatures of collisional setting supporting the presence of an orogenic belt in the interior of PEL. Zircons from the proximal sites display age ranges from Paleoproterozoic to Pan-African. Zircons from the distal site predominantly show ages ∼650 Ma, hinting at the possibility of a Tonian-Cryogenian event in the hinterland of the PEL sector, possibly in the GSMs. Our results provide a better understanding of the Neoproterozoic crustal evolution of the IAAS domain of the PEL sector.

中文翻译：

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印度-澳大利亚-南极缝合带域和东南极洲甘布尔采夫冰下山脉的新元古代地壳演化：来自近海沉积物的见解


伊丽莎白公主地 (PEL) 保留了冈瓦尼亚时代复杂交叉的造山带的错综复杂的融合，这些造山带被分支的东南极裂谷系统交叉切割。印度-澳大利亚-南极缝合带（IAAS）是一个广泛的造山带，通过伊丽莎白公主地的印度-南极地区连接德隆宁莫德地的非洲-南极地区和威尔克斯地区的澳大利亚-南极地区，接触到北部边界甘布尔采夫冰下山脉（GSM）。 GSM 和 IAAS 位于 PEL 内部，完全隐藏在冰盖内。由于地质证据不足，IAAS 和隐藏的 GSM 之间的联系仍然不明确。普里兹湾的海洋沉积物为探索 PEL 的这一部分提供了线索。在这项工作中，对海洋钻探计划 (ODP) 地点的沉积物进行了地球化学和锆石同位素分析，以了解 PEL、IAAS 和 GSM 的地壳演化：740、742 和 739（分别代表近端到相对远端的地点） 。沉积物地球化学表明，与地点 742 和 739 相比，地点 740 的沉积物较接近，不成熟，回收较少，并且化学风化程度更高。主量元素和微量元素的判别图提供了主动和被动大陆边缘特征。 739 和 742 地点的沉积物显示了裂谷背景特征，而 740 地点的沉积物描绘了碰撞环境特征，支持 PEL 内部存在造山带。近端地点的锆石显示年龄范围从古元古代到泛非。远端地点的锆石主要显示年龄约为 650 Ma，暗示 PEL 扇区腹地（可能在 GSM）可能发生托尼安-成冰期事件。 我们的研究结果有助于更好地了解 PEL 扇区 IAAS 域的新元古代地壳演化。