<p>Coupling X-ray diffraction, scanning electron microscopy, and computed microtomographic analyses, this study revealed that ash deposits from a single eruptive layer at Los Espinos Volcano contained three distinct types of juvenile ash clasts based on color and microtextural attributes. These present similar mineral phases but significant differences in vesicularity and microlite distribution, suggesting the fragments could originate from distinct parts of a differentially cooling magma body within the conduit. The morphological features of the juveniles reveal a dominance of ductile deformation, suggesting shallow magma fragmentation, with both strombolian and phreatomagmatic styles, highlighting a complex evolution and fragmentation process of magma within a single eruption pulse. This research offers a new perspective by emphasizing the importance of detailed ash analysis in understanding small-volume volcanic eruptions and improving knowledge of their eruptive histories. However, the single-layer focus provides only a snapshot; future work on multiple layers could reveal the volcano's full evolution.</p> Graphical abstract <p></p>