Abstract The Quetrupillan Volcanic Complex is a composite system, active since the Pleistocene. We combine petrological and geochemical data from its erupted products with structural and geometrical constraints applied to the overall system and region. We conclude that a basaltic source melt is hindered on its ascent through the crust due to a compressional tectonic regime, influenced further by the structural control imposed by the Liquine-Ofqui Fault Zone. The stalled melt evolves by fractional crystallisation within the crust and undergoes a degree of crustal contamination, resulting in a network of trachytic melt pockets within a transcrustal magmatic system. Eruptions sourced from these pockets have generated numerous lava flows with trachytic compositions, which have occurred from the summit and flanks of Quetrupillan during the Holocene. Occasionally, some of the basaltic source melt has reached shallow levels within the plumbing system with minor interaction with the trachytic melt, resulting in the eruption of lavas with basalt, basaltic andesite and trachyandesite compositions. We propose a conceptual model for the magmatic system of Quetrupillan, in which the Liquine-Ofqui Fault Zone plays an important role in exerting a structural control on the crust on which Quetrupillan resides, influencing magma residence times and pathways to the surface.

中文翻译：

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岩浆管道系统的构造约束：Quetrupillán Volcanic Complex (39°30′ S, 71°43′ W)，南安第斯山脉，智利

摘要 Quetrupillan 火山杂岩是一个自更新世以来活跃的复合系统。我们将来自其喷发产品的岩石学和地球化学数据与应用于整个系统和区域的结构和几何约束相结合。我们得出的结论是，玄武质源熔体在通过地壳上升时受到挤压，受 Liquine-Ofqui 断裂带的结构控制的进一步影响。停滞的熔体通过地壳内的分步结晶演化，并受到一定程度的地壳污染，从而在跨地壳岩浆系统中形成粗面熔体袋网络。源自这些岩穴的喷发产生了大量具有粗面成分的熔岩流，这些熔岩流发生在全新世期间 Quetrupillan 的顶峰和侧翼。偶尔，一些玄武岩源熔体在管道系统内达到浅层，与粗面熔体的相互作用很小，导致熔岩喷发，其中含有玄武岩、玄武质安山岩和粗面岩成分。我们提出了 Quetrupillan 岩浆系统的概念模型，其中 Liquine-Ofqui 断裂带在对 Quetrupillan 所在的地壳施加结构控制、影响岩浆停留时间和通往地表的路径方面发挥着重要作用。