Del spatter a las masas piroclásticas coherentes (lava-like) en depósitos intracráter del volcán Cabezo Segura (Región Volcánica de Calatrava)
- 1 Universidad del País Vasco UPV/EHU
ISSN: 1576-5172
Year of publication: 2012
Issue Title: VIII Congreso Geológico de España, Oviedo, 17-19 de julio, 2012.
Issue: 13
Pages: 845-848
Type: Article
More publications in: Geotemas (Madrid)
Abstract
Portions of the intra-crater deposits at the Cabezo Segura volcano (Calatrava Volcanic Province, Spain) are made of alternating spatter and coherent pyroclatic masses (so-called lava-like bodies). The two types of deposit were formed around lava fountains through the accumulation of hot, fluidal pyroclasts that agglutinated and coalesced on land. The contact between spatter and coherent pyroclastic masses is gradual and marked by the progressive decrease of void spaces (deposit densification) and increase of clast coalescence. The clast contours progressively disappear and the originally clastic deposit becomes a coherent rock barely different from an effusive lava. Nonetheless, relict clast shapes are preserved inside some coherent pyroclastic masses (blurred clast contours, enhanced weathering along clast margins, changes in degree of crystalinity, etc.) and zones with patch vesiculation that attest to their fragmental origin. The occurrence of such type of deposits strengths the importance of the past Hawaiian activity in the Calatrava Volcanic Province.