FORO: A new type of maar volcano from the State of Durango-the El Jagüey-La Breña complex reinterpreted; a reply

Abstract

The major point of the paper under discussion (Swanson, 1989) is that the El Jagüey-La Breña complex, located in Durango's Guadiana valley (Figure 1), is a previously unrecognized type of maar volcano, in which a caldera (La Breña) formed following eruption of supporting material through an adjacent maar (El Jagüey). The paper proposed a simple developmental history (Figure 2), consistent with the geology and location of the volcanic complex. The complex started as a scoria cone, like 100 others in the valley; it evolved into a breach scoria cone, as most scoria cones do; then water encroachment briefly and dramatically converted the eruption style from magmatic to phreatomagmatic, creating El Jagüey maar and the adjoining La Breña caldera. The objections presented by Aranda-Gómez and coworkers (1990), termed conclusive and supportive, can be categorized as: (1) questioning the one-maar interpretation; (2) questioning details of the developmental model for the El Jagüey-La Breña complex; or as (3) supportive of their own two-maar interpretation. I welcome the opportunity to answer to their objections and elaborate on this distinctive type of maar volcano.

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