Abstract A comprehensive understanding of the magmatic system evolution and petrogenetic environment is crucial for the correct interpretation of magmatic zircon age spectra. In the Central Andes, a protracted Late Paleozoic period of collisional to post-collisional magmatism was followed by Late Triassic emplacement of post-orogenic plutons and associated mantle precursors. Some of these magma products are crowded with inherited zircons with a large age span at the sample scale (>25 Myr). This work deals with two contrasting inheritance-rich plutons: the peraluminous cordierite-bearing Los Tilos pluton (LTp) and the peralkaline hypersolvus Ferro-edenite/hedenbergite-bearing Monte Grande pluton (MGp). Both plutons were derived from melting of the crust: the peraluminous S-type granite represents derivation from mixed materials, whereas the peralkaline A-type leucogranite embodies nearly eutectic melts enriched in incompatible elements. Rapid cooling of entrained assemblages suggests that segregation and subsequent ascent was rapid, following emplacement-site isobaric cooling at ca. 3.5 and 2 kbar, for LTp and MGp respectively. Most zircons were inherited; their disparate chemistry originates from contrasting sources, unveiling an open-system behavior. The effects of variations in magma temperature, emplacement pressure, and water content were evaluated in light of zircon entrainment and dissolution potential, within a thermodynamically consistent framework. Relatively dry magmas ( We suggest that the large age span observed in zircon samples of both plutons reflects a long-lived source that fed arc-related granites in the Early to Middle Triassic, culminating in the Late Triassic with the final extraction of highly enriched crustal melts, in a post-orogenic context. Dry high-silica (>75 SiO2 wt%) magmatic flare-ups, in extensional settings, fulfill the inheritance requisites presented here. Contrastingly, a broad zircon age span in large calc-alkaline batholiths emplaced at similar depths, reflect not source processes but rather magmatic erosion, crystal armoring and recycling of previous magma batches, and a complex crystallization history, spanning the whole duration of batholith construction.

中文翻译：

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来自晚三叠世后造山岩体、高安第斯山脉、智利中部（~30°S）的长寿命来源的锆石遗传：岩浆反馈和成岩意义

摘要 全面了解岩浆系统演化和成岩环境对于正确解释岩浆锆石年龄谱至关重要。在安第斯山脉中部，经历了一个漫长的晚古生代碰撞到碰撞后岩浆作用，随后是晚三叠世后期造山岩体和相关地幔前体的侵位。这些岩浆产物中的一些在样本尺度（> 25 Myr）上挤满了年龄跨度大的继承锆石。这项工作涉及两种截然不同的富含继承的岩体：含过铝质堇青石的 Los Tilos 岩体 (LTp) 和含过碱性超溶解性铁伊丹岩 / 菱镁矿的 Monte Grande 岩体 (MGp)。两种岩体均来自地壳熔化：过铝质 S 型花岗岩代表来自混合材料，而过碱性 A 型无色花岗岩则体现了富含不相容元素的几乎共晶熔体。夹带组合的快速冷却表明分离和随后的上升是快速的，在大约 10 的就位点等压冷却之后。LTp 和 MGp 分别为 3.5 和 2 kbar。大多数锆石是遗传的；它们不同的化学反应来自不同的来源，揭示了开放系统的行为。在热力学一致的框架内，根据锆石夹带和溶解潜力，评估了岩浆温度、侵位压力和含水量变化的影响。相对干燥的岩浆（我们认为在两个岩体的锆石样本中观察到的大年龄跨度反映了一个长期存在的源，它在早三叠世到中三叠世为弧形相关花岗岩提供营养，在造山后的背景下，随着最终提取高度富集的地壳熔体，在晚三叠世达到高潮。干燥的高二氧化硅 (>75 SiO2 wt%) 岩浆爆发，在伸展设置中，满足这里介绍的继承要求。相比之下，位于相似深度的大型钙碱性基岩中广泛的锆石年龄跨度反映的不是源过程，而是岩浆侵蚀、晶体装甲和先前岩浆批次的再循环，以及复杂的结晶历史，跨越基岩建造的整个持续时间。