pyroklastisia

Pyroklastisia is a term that appears in some geological glossaries to denote the study of, or the assemblage of, materials and processes produced by explosive volcanic activity. In contemporary English-language volcanology, the more common terms are pyroclastic, tephra, or pyroclastic materials, and pyroklastisia is considered a less standard or regional usage. The concept, however, aligns with the broad field of pyroclastics, which concerns the fragments erupted during volcanic explosions and the environments in which they are deposited.

The term broadly covers pyroclasts—fragments such as volcanic ash, pumice, lapilli, and volcanic bombs—and the transport and depositional processes that move and cement them. It encompasses airfall tephra produced by explosive ejection into the atmosphere, as well as pyroclastic density currents, including flows and surges, that transport material along the ground. Depositional products include ash beds, pumice rafting, ignimbrites, and various lithified pyroclastic deposits.

In practice, pyroklastisia as a label is rarely used in modern English literature; it has historical or regional usage and is often replaced by specific terms like pyroclastic flow, tephra, or ignimbrite. When encountered, it signals a focus on both the fragmented volcanic ejecta and the mechanisms by which these materials are created, transported, and preserved in the geological record.

See also: pyroclastic flow, tephra, ignimbrite, volcanology.