Maars to calderas: end-members on a spectrum of explosive volcanic depressions

Frontiers in Digital Humanities

Valentine, Greg A.¹  Taddeucci, Jacopo³  Palladino, Danilo M.⁴  Sottili, Gianluca⁵ 

[1] di Roma, Dipartimento di Scienze della Terra, Rome, Italy;Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy;Istituto di Geologia Ambientale e Geoingegneria (IGAG)-CNR, Rome, Italy;Sapienza-UniversitàUniversity at Buffalo, Geological Sciences, 411 Cooke Hall, University at Buffalo, Buffalo, 14260, New York, United States

关键词: Maar;    diatreme;    caldera;    phreatomagmatic;    Explosive eruptions;   

DOI  :  10.3389/feart.2015.00036

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

We discuss maar-diatremes and calderas as end-members on a spectrum of negative volcanic landforms (depressions) produced by explosive eruptions (note – we focus on calderas formed during explosive eruptions, recognizing that some caldera types are not related to such activity). The former are dominated by ejection of material during numerous discrete phreatomagmatic explosions, brecciation, and subsidence of diatreme fill, while the latter are dominated by subsidence over a partly evacuated magma chamber during sustained, magmatic volatile-driven discharge. Many examples share characteristics of both, including landforms that are identified as maars but preserve deposits from non-phreatomagmatic explosive activity, and ambiguous structures that appear to be coalesced maars but that also produced sustained explosive eruptions with likely magma reservoir subsidence. A convergence of research directions on issues related to magma-water interaction and shallow reservoir mechanics is an important avenue toward developing a unified picture of the maar-diatreme-caldera spectrum.

【 授权许可】

CC BY