The Terra Nova Intrusive Complex (TNIC) in northern Victoria Land, Antarctica, results from widespread magmatism during the Early Paleozoic Ross Orogeny. According to field relationships, geochemistry, and geochronology data, the northern part of the TNIC comprises the Browning Intrusive Unit (BIU), which is associated with an arc crustal melting including migmatization of the Wilson Metamorphic Complex, and the later Campbell Intrusive Unit (CIU), which is attributed to the mantle and crustal melting processes. Zircon U-Pb ages suggest Late Neoproterozoic to Early Cambrian protolith with Late Cambrian metamorphism (502 ± 15 Ma) in the WMC, Late Cambrian formation (~500 Ma) of the BIU, and Early Ordovician formation (~480–470 Ma) of the CIU. Sr-Nd isotopic characteristics of the BIU indicate predominant crustal component (εNd_(t) = −8.7 to −8.9), whereas those of the CIU reflect both mantle (εNd_(t) = 1.8 to 1.6) and crustal (εNd_(t) = −4.0 to −7.5) compositions. These results suggest that the northern TNIC magmatism occurring at ~500–470 Ma originated from partial melting of the mantle–mafic crust components and mixing with felsic crust components. By integrating the results with previous studies, the TNIC is considered to be formed by a combination of the mantle and mafic crust melting, crustal assimilation, felsic crust melting, and magma mixing during the Ross Orogeny.

中文翻译：

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南极维多利亚州北部 Terra Nova 湾区早古生代侵入岩的地球化学和年代学

Terra Nova Intrusive Complex (TNIC) 位于南极洲维多利亚地北部，是早古生代罗斯造山运动期间广泛的岩浆作用的结果。根据现场关系、地球化学和地质年代学数据，TNIC 的北部包括布朗宁侵入单元（BIU），它与包括威尔逊变质杂岩混杂在内的弧形地壳熔融有关，以及后来的坎贝尔侵入单元（CIU） )，这归因于地幔和地壳的熔化过程。锆石 U-Pb 年龄表明晚新元古代至早寒武世原岩具有 WMC 晚寒武世变质作用 (502 ± 15 Ma)、BIU 晚寒武世地层 (~500 Ma) 和早奥陶世地层 (~480-470 Ma) CIU。BIU 的 Sr-Nd 同位素特征表明主要的地壳成分（εNd_(t) = -8.7 到 -8.9)，而 CIU 的那些反映了地幔 (εNd _(t) = 1.8 到 1.6) 和地壳 (εNd _(t) = -4.0 到 -7.5) 的成分。这些结果表明，发生在~500-470 Ma 的北部 TNIC 岩浆活动起源于地幔-基性地壳组分的部分熔融并与长英质地壳组分混合。综合前人研究结果，认为TNIC是罗斯造山运动期间地幔与基性地壳熔融、地壳同化、长英质地壳熔融和岩浆混合共同作用形成的。