Richard E. Ernst1, Jelle Zeilinga de Boer2, Peter Ludwig2 , Taras Gapotchenko2
1 Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario Canada
KlA OE8, (rernst@gsc.nrcan.gc.ca)
2 Department of Earth and Environmental Sciences, Wesleyan University,
Middletown, CT 06459-0139, USA (jdeboer@wesleyan.edu)
Abstract
The relationship between flood basalts and feeder dykes is investigated
through an anisotropy of magnetic susceptibility (AMS) study of CAMP event
(200 Ma) magmatism in the Fundy basin of southeastern Canada. Over
a 200 km strike length, the North Mountain basalts exhibit a consistent
N-NE emplacement direction flow pattern (based on the orientation of maximum
AMS axes). Less definitively, the data suggest that the lower lavas
(including the Grand Manaan basalts) have a NE-SW flow axis, while the
middle and upper flow units have a more N-S flow axis. The Swallowtail
dyke of Grand Manan Island exhibits sub-vertical flow based on AMS data.
Its presumed extension along the axial zone of the Fundy basin is the possible
feeder for as least some of the North Mountain flows.