Volcanic arc clusters are groups of adjacent volcanic edifices that allow the investigation of geochemical changes occurring through time within a limited area (< few hundreds of km²). As such they may increase our understanding of processes that lead to magma differentiation in arcs. Geochemical changes over time in volcanic clusters can be related to source or intracrustal processes. Here, we show that magmatic rocks of 9 edifices of the Chachimbiro-Pulumbura-Pilavo-Yanaurcu volcanic cluster, in the frontal arc of Ecuador, display temporal changes of major and trace elements as well as Pb isotopes during their ~13 Ma long life history (13 Ma to 6 ka). Additionally, geochemical compositions of magmatic rocks of these edifices also become more homogeneous through time. Fractionation, assimilation and recharge models suggest that the changes in geochemical composition and in the compositional spread of erupted materials of the cluster are controlled by an increased depth of magma evolution since ~300–400 ka ago. We propose two speculative scenarios to explain the deepening of magmatic evolutionary processes since ~300–400 ka in the studied cluster. Nonetheless, a higher geochronological and geochemical resolution is needed to determine the cause and exact timing of such a switch as well as its synchronicity or diachroneity with respect to the geochemical changes observed in other volcanic centers along and across the Ecuadorian arc.

火山弧群是相邻的火山构造群，可以研究有限区域内（<几百公里^2）内随时间发生的地球化学变化。）。因此，它们可能会加深我们对导致弧形岩浆分化的过程的理解。火山群中地球化学随时间的变化可能与源或壳内过程有关。在这里，我们发现厄瓜多尔前弧的Chachimbiro-Pulumbura-Pilavo-Yanaurcu火山群的9个建筑物的岩浆岩在其〜13 Ma的长寿命历史中显示出主要和微量元素以及Pb同位素的时空变化。 （13 Ma至6 ka）。另外，随着时间的流逝，这些建筑物的岩浆岩的地球化学成分也变得更加均匀。分馏，同化和补给模型表明，自约300-400 ka以来，岩浆喷发物质的地球化学组成和组成扩散的变化受岩浆演化深度的增加控制。我们提出了两种推测性的情况，以解释自研究集群以来约300–400 ka以来岩浆演化过程的加深。尽管如此，仍需要更高的地质年代和地球化学分辨率来确定这种转换的原因和确切时机，以及相对于沿厄瓜多尔弧线及整个厄瓜多尔弧线在其他火山中心观测到的地球化学变化而言，其同步性或双错性。