Canada Basin extinct ridge

ID: 4-12

Ocean: Marginal basin
Spreading center type: Large-scale MOR and but also recently argued to have been a back-arc basin spreading ridge (Lundin et al., 2017)
Time of cessation: Ca. 127 Ma, after chron M12 (Grantz et al., 1998)

Review of previous studies:

From aeromagnetic surveys across the basin, Taylor et al. (1981) identified symmetric magnetic anomalies, trending N-S and inferred that an extinct spreading axis was located in the center the basin. The basin was proposed to have formed between 160 Ma and 132 Ma, opening in an east-west direction (Taylor et al., 1981).

Observations and comments:

No bathymetric expression of the extinct spreading center is evident, however a subdued negative gravity anomaly can be identified at the former axis and has similar form and magnitude (~15 mGals peak to trough) to better defined extinct ridges of older age.

References


Lundin, E.R. and Doré, A.G., 2017, The Gulf of Mexico and Canada Basin: Genetic Siblings on Either Side of North America, GSA Today, v. 27, no. 1, p. 4-11.

Grantz, A., Clark, D.L., Phillips, R.L., Srivastava, S.P., Blome, C.D., Gray, L.B., Haga, H., Mamet, B.L., McIntyre, D.J., McNeil, D.H. and Mickey, M.B., 1998. Phanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada basin, and the geometry and timing of rifting in the Amerasia basin, Arctic Ocean. Geological Society of America Bulletin, 110(6), pp.801-820.

Taylor, P.T. et al., 1981. Detailed aeromagnetic investigation of the Arctic Basin. II. , 86, pp.6323–6333.

Maps showing the location of extinct ridge segments

Depth profiles across the axes of extinct ridge segments

Gravity profiles across the axes of extinct ridge segments