Lapilli tuff as evidence of Early Jurassic Strombolian-type volcanism in Scania, southern Sweden

Abstract

Central Scania, southernmost Sweden, is penetrated by more than one hundred basaltic volcanic necks of Jurassic age. Pyroclastics, related to the volcanic necks, have been investigated to reveal the volcanic environment, and the eruptive character required to produce the pyroclastics. Based on textural and petrographical evidence, a Strombolian-type eruptive character is suggested. The sediment, a lapilli tuff, is clay altered due to early diagenetic processes, but traces of palagonite reveal a former basaltic composition of the lapilli tuff. The volcanoes were part of a monogenetic volcanic field and deposition of the pyroclastic sediment took place on land, probably close to oceanic water.

Keywords:

• Djupadal formation
• Scania
• Sweden
• lapilli tuff
• pyroclastics
• Jurassic
• Strombolian-type eruption
• basalt