ISSN:
1432-0819
Schlagwort(e):
Réunion Island Explosive volcanism Subaerial pyroclastic deposits Marine ash layers Geochemistry Land–sea correlation Chronology
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Geologie und Paläontologie
Notizen:
Abstract. The explosive activity of Réunion volcanoes since approximately 260 ka is investigated through detailed sedimentologic, isotopic, and geochemical analyses of three deep-sea marine cores. Twenty-four eruptions from Piton des Neiges and one from Piton de la Fournaise are identified. The marine stratigraphic record of ash layers is undisturbed, whereas corresponding tephra deposits on land may have disappeared or have been disturbed through erosion and volcano-tectonic processes. Consequently, the new data presented herein may be regarded as a reference sequence of the main explosive events of Réunion. In addition, the chronology based on δ18O stratigraphy offers continuous time constraints with respect to other isotopic methods used for dating lavas. Explosive events were more frequent during the period 180–150 ka. The comparison of major element composition and chronologic data between known explosive deposits on land and marine ash layers allows us to propose correlations between marine and land data. However, most of the marine ash layers do not yet have a recognized subaerial counterpart. For the main explosive events known on land, we propose the following succession: Sainte Suzanne formations, ≥257–240 ka; Dalle Soudée Formation, 218 ka; Salazie formations, two groups at 165–168 ka and 80–102 ka; Saint Gilles formations, 175 ka; Saint Louis formations, 158–161 ka; and Saint Pierre formations, 165–166 ka.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s004450000095
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