| Title | Geophysical modeling of Devonian plutons in the southern Gulf of St. Lawrence: implications for Appalachian terrane boundaries in Maritime Canada |
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| Author | Cook, L A; Dehler, S A ; Barr, S M |
| Source | Canadian Journal of Earth Sciences vol. 44, issue 11, 2007 p. 1551-1565, https://doi.org/10.1139/e07-038 |
| Image |  |
| Year | 2007 |
| Alt Series | Earth Sciences Sector, Contribution Series 20070065 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Prince Edward Island; New Brunswick; Nova Scotia; Eastern offshore region |
| NTS | 11B; 11C; 11D; 11E; 11F; 11G; 11K; 11J; 11L; 11M; 11N; 11O; 21A; 22B; 22H; 22G; 22I; 22J; 22O; 22P |
| Area | St. Lawrence Gulf |
| Lat/Long WENS | -66.0000 -58.0000 48.0000 44.0000 |
| Subjects | structural geology; tectonics; geochronology; general geology; magnetic anomalies; seismic data; modelling; Ganderian terrane; Brookville terrane; Bras d'Or terrane; Ganderia-Avalonia boundary; Canso
fault |
| Illustrations | geological sketch maps; location maps; magnetic anomaly maps |
| Program | Secure Canadian Energy Supply |
| Released | 2007 11 01 |
| Abstract | A prominent positive magnetic anomaly spans the 100 km distance between Prince Edward Island and Cape Breton Island in the southern Gulf of St. Lawrence. The anomaly occurs in an area of complex
structure where Appalachian terrane boundaries are poorly resolved because of thick late Paleozoic sedimentary cover. Analysis of the magnetic anomaly led to the interpretation that it is produced by four separate, approximately circular, source
bodies aligned along the northwesterly trend of the anomaly. Seismic data, physical property measurements, and magnetic and gravity anomalies were used to further investigate the anomaly sources through forward modeling techniques. The four source
bodies have densities and magnetic susceptibilities compatible with dioritic to granitic compositions. Modeling also suggests that basement to the north of the plutons has higher density and susceptibility than basement to the south, and hence the
source bodies are interpreted as plutons emplaced along the boundary between Ganderian composite terranes to the north and the Ganderian Brookville - Bras d'Or terrane to the south. This interpretation suggests that the Ganderia-Avalonia boundary is
located farther south, and shows the need for re-evaluation of the location and role of the Canso fault in offsetting terranes between Cape Breton Island and southern New Brunswick. |
| GEOSCAN ID | 223809 |
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