Osmium isotopes, whole rock and mineral geochemical data from peridotite xenoliths from two Miocene McMurdo Volcanic Group cinder cones in the Transantarctic Mountains (TAM) in Southern Victoria Land, Antarctica, reveal that the underlying mantle preserves evidence for major mid-Proterozoic lithosphere formation despite the crust being dominated by late Neoproterozoic-Ordovician (~0.65–0.47 Ga) rocks. The Hooper Crags xenolith suite is dominated by harzburgites with highly refractory olivine Mg# (up to 92.3) and depleted bulk rock major and platinum group element + Re abundances, with ¹⁸⁷Os/¹⁸⁸Os ratios indicating depletion in the mid-Proterozoic. Pipecleaner Glacier xenoliths, 18 km distant, are lherzolites with olivine Mg# (<91) and fertile major and platinum group element abundances, with Os isotope abundances defining an aluminochron that also indicates mid-Proterozoic depletion. Although exposed crust along this portion of Antarctica reveals only minor evidence for Proterozoic magmatism, the major episode of lithosphere formation indicated by the Os isotope data is supported by published bulk rock Sm-Nd isotope and zircon εHf mantle model ages of Neoproterozoic to Ordovician plutonic rocks. The heterogeneous circum-cratonic mid-Proterozoic mantle under Southern Victoria Land has therefore persisted on a Ga timescale, including through the formation and destruction of Rodinia and Gondwana supercontinents as well as extensive crustal melting and emplacement of the Ferrar large igneous province. This longevity may be due to the thick (>250 km) East Antarctic Craton lithosphere shielding the immediately adjacent circum-cratonic mantle from being affected by convective asthenosphere-driven erosion. This contrasts with mantle lithosphere accreted distally to the East Antarctic Craton (represented by the now-detached Zealandia continent), which did not attain extreme thickness and has therefore been more susceptible to tectonic reworking and lateral translation.

来自南极洲维多利亚州南部跨南极山脉 (TAM) 的两个中新世麦克默多火山群火山灰锥的橄榄岩包体的锇同位素、全岩和矿物地球化学数据表明，下伏地幔保留了主要中元古代岩石圈形成的证据地壳以晚新元古代-奥陶纪（~0.65-0.47 Ga）岩石为主。Hooper Crags 捕虏体套件以具有高难熔橄榄石 Mg#（高达 92.3）和耗尽的大块岩石主要元素和铂族元素 + Re 丰度的菱镁矿为主，具有¹⁸⁷ Os/ ¹⁸⁸Os 比率表明中元古代的耗竭。Pipecleaner Glacier 捕虏体，距离 18 公里，是橄榄石 Mg# (<91) 和肥沃的主要元素和铂族元素丰度的锂辉石，Os 同位素丰度定义了铝质计时，这也表明中元古代耗竭。尽管沿南极洲这一部分裸露的地壳仅揭示了元古代岩浆作用的次要证据，但 Os 同位素数据表明的岩石圈形成的主要事件得到了已发表的新元古代至奥陶纪深成岩 Sm-Nd 同位素和锆石 εHf 地幔模型年龄的支持. 因此，南维多利亚土地下的异质环克拉通中元古代地幔在 Ga 时间尺度上持续存在，包括通过罗迪尼亚和冈瓦纳超大陆的形成和破坏以及费拉尔大型火成岩省的广泛地壳熔化和就位。这种长寿可能是由于南极东部克拉通厚厚的岩石圈（>250 公里）保护了紧邻的环克拉通地幔不受对流软流圈驱动的侵蚀的影响。这与在南极东部克拉通（以现在分离的西兰大陆为代表）远端增生的地幔岩石圈形成对比，后者没有达到极端的厚度，因此更容易受到构造改造和横向平移的影响。250 公里）南极东部克拉通岩石圈保护紧邻的环克拉通地幔不受对流软流圈驱动的侵蚀影响。这与在南极东部克拉通（以现在分离的西兰大陆为代表）远端增生的地幔岩石圈形成对比，后者没有达到极端的厚度，因此更容易受到构造改造和横向平移的影响。250 公里）南极东部克拉通岩石圈保护紧邻的环克拉通地幔不受对流软流圈驱动的侵蚀影响。这与在南极东部克拉通（以现在分离的西兰大陆为代表）远端增生的地幔岩石圈形成对比，后者没有达到极端的厚度，因此更容易受到构造改造和横向平移的影响。