Adams et al 2021. Detrital zircon provenance of Permian to Triassic Gondwana sequences, Zealandia and eastern Australia. Supplemental Files SF1 and SF2

Permian Parapara Group and Triassic Topfer Formation are small clastic sedimentary outliers that rest on Cambrian to Devonian basement terranes in the Western Province of South Island, New Zealand. Four new detrital zircon U-Pb age datasets from sandstones in these outliers and four from age-equivalent eastern Australian sandstones reveal age and provenance information about former Gondwana intracontinental basins. Youngest significant zircon age populations of 264±6, 261±2 Ma (Parapara Group) and 215±2 Ma (Topfer Formation) match fossil ages and indicate broadly syn-depositional igneous activity. The provenance of the igneous detritus was probably the nearby Median Batholith and/or its volcanic equivalents. Zircons in a third Parapara sandstone are mainly Cambrian and Precambrian in age and represent a separate petrofacies with a local Western Province basement terrane provenance. Intra-basin provenance switching between Gondwana margin arc and older basement sources is now documented from Zealandia’s Gondwana basin sequences as well as those from Australia and Antarctica.

二叠系帕帕拉群（Permian Parapara Group）与三叠系托普弗组（Triassic Topfer Formation）是分布于新西兰南岛西部省寒武系至泥盆系基底地体之上的小型碎屑沉积孤立露头。本次研究针对上述孤立露头中的砂岩样品，构建了4套全新的碎屑锆石（detrital zircon）U-Pb年龄数据集；同时针对澳大利亚东部同期砂岩样品完成了4套同类数据集测试，二者共同揭示了古冈瓦纳（Gondwana）大陆内部陆内盆地的年代学与物源（provenance）特征。帕帕拉群的主要锆石年龄众数为264±6 Ma、261±2 Ma，托普弗组的年龄众数为215±2 Ma，上述测年结果与化石年代一致，指示研究区存在与沉积作用同期的广泛岩浆活动。上述岩浆成因碎屑的物源大概率来自邻近的中央岩基（Median Batholith）及其同期火山岩相。第三件帕帕拉群砂岩样品中的锆石主体为寒武纪及前寒武纪年龄，代表了一套以本地西部省基底地体为物源的独立岩石相（petrofacies）。目前，研究者已在西兰大陆（Zealandia）的冈瓦纳盆地沉积序列，以及澳大利亚、南极洲的同期沉积序列中，均观测到冈瓦纳大陆边缘弧与古老基底两种物源在盆地内部的交替转换现象。