The recurrent explosive eruptions of Calbuco (Andean Southern Volcanic Zone (SVZ)) threat a rapidly expanding touristic and economic region of Chile. Providing tighter constraints on its magmatic system is therefore important for better monitoring its activity. Calbuco is also distinguished by hornblende-bearing assemblages that contrast with the anhydrous parageneses of most Central SVZ volcanoes. Here we build on previous work to propose a detailed petrological model of the magmatic system beneath Calbuco. Geochemical data acquired on a hundred samples collected in the four units of the volcano show no secular compositional change indicating a steady magmatic system since ~ 300 ka. A tholeiitic Al₂O₃-rich (20 wt. %) basalt (Mg# = 0.59) is the parent magma of a differentiation trend straddling the tholeiitic/calc-alkaline fields and displaying a narrow compositional Daly gap. Amphibole crystallization was enabled by the higher H₂O content of the basalt (3–3.5 wt. % H₂O at 50 wt. % SiO₂) compared to neighboring volcanoes. This characteristic is inherited from the primary mantle melt and possibly results from a lower degree of partial melting induced by the mantle wedge thermal structure. Although macrocrysts are not all in chemical equilibrium with their host rocks and were thus presumably unlocked from the zoned crystal mush and transported in the carrier melt, the bulk-rock trend follows both experimental liquid lines of descent and the chemical trend of calculated melts in equilibrium with amphibole (AEMs). These contradictory observations can be reconciled if minerals are transported in near cotectic proportions. The AEMs overlap the Daly gap revealing that the missing liquid compositions were present in the storage region. Geothermobarometers all indicate that the chemical diversity from basalt to dacite was acquired at a shallow depth (210–460 MPa). We suggest that differentiation from the primary magma to the parental basalt took place either in the same storage region or at the MOHO.

卡尔布科（安第斯南部火山区（SVZ））的周期性爆炸性爆发威胁到智利快速发展的旅游和经济区域。因此，对其岩浆系统提供更严格的约束对于更好地监测其活动很重要。Calbuco的另一个特点是带有角闪闪发光的组合，这与大多数中部SVZ火山的无水副生物形成鲜明对比。在这里，我们以先前的工作为基础，提出Calbuco之下岩浆系统的详细岩石学模型。从火山四个单元中收集的一百个样品获得的地球化学数据表明，自〜300 ka以来，长期组成没有变化，表明岩浆系统稳定。可塑性的Al ₂ O ₃富含玄武岩（20 wt。％）（Mg＃= 0.59）是分化趋势的母岩浆，横跨在高岭土/钙碱性矿场上并显示出狭窄的达利间隙。玄武岩中较高的H ₂ O含量（在50 wt。％SiO _2下为3-3.5 wt。％H ₂ O ）使闪石的结晶得以实现）与邻近的火山相比。该特征是从主要的地幔熔体继承的，并且可能是由于地幔楔形热结构引起的较低程度的部分熔解所致。尽管大晶体并非都与其宿主岩石处于化学平衡状态，因此大概可以从带状晶体糊状物中解开并在载体熔体中运输，但整体岩石趋势既遵循实​​验的下降趋势线，也遵循计算得出的熔体处于平衡状态的化学趋势。与闪石（AEMs）。如果矿物质以接近共晶的比例运输，则这些矛盾的观察结果是可以调和的。AEM与Daly间隙重叠，表明在存储区域中存在丢失的液体成分。地热气压计均表明，从玄武岩到钠铁矿的化学多样性是在较浅的深度（210-460 MPa）下获得的。我们建议从原浆岩向玄武岩母岩的分化发生在相同的储藏区或莫霍面。