Tectonics of the Ålen area, central Norway

Investigation of primary features preserved within the Tremadocian - Lower Ordovician Fundsj∅ Group indicate that the succession accumulated in a deepwater environment. The ca. 4-5 km thick Fundsj∅ Group exposed in the Ålen area is dominated by thin-bedded, terrigenous clastic metasediments which exhibit gradational contacts with mafic dominated bi-modal volcanics. Blastoporphyritic to blasto-ophitic diabase sills (0.5 - 3 m thick) compose ca. 20 - 30% of the metavolcanic Hersj∅ and Reitan Formations, and were emplaced as shallow intrusive units contemporaneous with volcanic activity. Localized preservation of relict coarse pyroclastic textured rocks and cIast-within-clast fragments attest to the occasional occurrence of phreatomagmatic explosions. Very thin-bedded, fine-grained amphibolite which exhibits mm scale planar parallel Iaminae and non-erosive contacts suggest deposition by marine fallout. Primary features preserved within the terrigenous clastic Gudå, Kjurudal, and Slågrov Formations indicate deposition by turbidity currents throughout the succession. A new stratigraphic correlation between the Dictyonema schist of the Nordaunevol locality, with the Kjurudal Fm. of this paper is proposed based on recent detailed mapping in the Ålen and southeast Haltdalen area. This correlation suggests that the Fundsj∅ Group is largely of Tremodocian - Lower Ordovician age. The lithofacies contained within the oldest (Gudå Fm.) to youngest (Slågrov Fm.) formations in the Fundsj∅ Group suggest that this succession represents an accumulation of syn-rift to post-rift sediments deposited oceanward of the hinge zone of the Baltoscandian continent.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Geological Sciences

Department dc:contributor.department

Geological Sciences

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1988

Author dc:creator

• Mandeville, Charles W.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/51906

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/51906