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Emsian synorogenic paleogeography of the Maine Applachians

Journal of Geology

By:
and
DOI: 10.1086/340634

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Abstract

The Acadian deformation front in the northern Appalachians of Maine and New Hampshire can now be closely located during the early Emsian (Early Devonian; 408-406 Ma). Tight correlations between paleontologically and isotopically dated rocks are possible only because of a new 408-Ma time scale tie point for the early Emsian. The deformation front lay between a belt of Lower Devonian flysch and molasse that were deposited in an Acadian foreland basin and had not yet been folded and a belt of early Emsian plutons that intruded folded Lower Devonian rocks. This plutonic belt includes the newly dated Ore Mountain gabbro (U/Pb; 406 Ma), which hosts magmatic-sulfide mineralization. Along the deformation front, a 407-Ma pluton that locally truncates Acadian folds (Katahdin) was the feeder to volcanic rocks (Traveler Rhyolite; 406-407 Ma) that are part of the foreland-basin succession involved in these same folds. The Emsian igneous rocks thus define a syncollisional magmatic province that straddled the deformation front. These findings bear on three alternative subduction geometries for the Acadian collision.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Emsian synorogenic paleogeography of the Maine Applachians
Series title:
Journal of Geology
DOI:
10.1086/340634
Volume
110
Issue:
4
Year Published:
2002
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Geology
First page:
483
Last page:
492