posteruptive

Posteruptive is an adjective used in geology and volcanology to describe events, processes, or features that occur after a volcanic eruption. It is used to distinguish post-eruption phenomena from those that occur prior to eruption (pre-eruptive) or during eruption (syn-eruptive). The term is often applied to secondary alteration of erupted materials, post-emplacement modification of volcanic rocks, and geochemical or mineralogical changes driven by hydrothermal fluids, weathering, or sedimentation that follow an eruption.

In practice, posteruptive processes include hydrothermal alteration of ash fall tephra or lava flows forming clays, zeolites, and other secondary minerals; alteration halos around eruption-fed deposits; weathering of volcanic edifices leading to soil formation and mineral redistribution; and remobilization of elements within eruption products after emplacement. The concept helps researchers interpret the chronological sequence of volcanic systems and the evolution of eruption products after emplacement.

Etymology: from post- meaning after and eruptive, indicating timing relative to eruption. The term is used across geology disciplines, including petrology, volcanology, and stratigraphy, to frame discussions of post-eruption histories.

See also: pre-eruptive, syn-eruptive, post-eruptive processes (volcanology), tephrochronology, rock alteration, weathering.