U.S. Geological Survey deep seismic reflection profile across the Gulf of Maine

Geological Society of America Bulletin
By: , and 

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Abstract

Deep seismic reflection and magnetic data suggest that the Gulf of Maine is underlain by four crustal blocks of differing reflection and magnetic character. Two of these blocks, the Gulf of Maine fault zone and adjacent central plutonic zone, can be correlated with Avalonian rocks in southern New England and New Brunswick. The boundary between them, the Fundy fault, projects onshore near the Ponkapoag fault in southeastern Massachusetts in a region where no major crustal boundary has (yet) been identified. A third block, called the southern plutonic zone, is interpreted as Avalonian, although the reflection and magnetic data are ambiguous. The fourth block, along the rifted continental margin, is correlated with Meguma rocks of Nova Scotia. The late Paleozoic Variscan front crosses the Gulf of Maine within the Gulf of Maine fault zone and indicates significant compressional movement rather than strike-slip.

 

The Moho surface throughout the region is essentially flat and may have been produced by Mesozoic crustal extension. Associated modification of the lower crust was minimal in the northern Gulf and may have been moderate in the central and southern Gulf. The Franklin rift basin formed by reactivation of the inferred Avalon-Meguma boundary beneath Georges Bank as a low-angle detachment.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title U.S. Geological Survey deep seismic reflection profile across the Gulf of Maine
Series title Geological Society of America Bulletin
DOI 10.1130/0016-7606(1988)100<0172:USGSDS>2.3.CO;2
Volume 100
Issue 2
Year Published 1988
Language English
Publisher Geological Society of America
Contributing office(s) Coastal and Marine Geology Program
Description 13 p.
First page 172
Last page 184
Country United States
Other Geospatial Gulf of Maine
Online Only (Y/N) N
Additional Online Files (Y/N) N