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A textural study of basaltic tephras from lower Tertiary diatomites in northern Denmark in Tephra studies.

Auteurs :
PEDERSEN, A. K.
JORGENSEN, K. A.
SELF, S.
SPARKS, R. S. J.
NATO Advanced Study Institute, International

Description :
More than 200 tephra layers deposited in early Tertiary diatomite and clay in northern Denmark record explosive volcanism in the Skagerrak and in the North Sea. The early activity is basaltic, rhyolitic, and mafic and salic alkaline while later activity is exclusively tholeiitic Fe-Ti-basaltic. Several of the younger basaltic tephras exceed 4 km by volume. The morphology and grain size of the tephras indicate both subaerial and phreatic activity. The Fe-Ti-basaltic tephras are distinctly surtseyan in type, wich may indicate volcanism in a shallow sea environment.


Type de document :
Congrès

Source :
Tephra studies as a tool in quaternary research, 1980, p. 213-218, Références bibliographiques : 20 réf.

Date :
1981

Editeur :
Pays édition : Inconnu

Langue :
Anglais
Droits :
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