11
$\begingroup$

Why is there a bend in the Lomonosov Ridge?

This is a supplementary question to that asked by Sabre Tooth in What is the tectonic explanation for parallel ridges in the Arctic ocean

$\endgroup$
5
$\begingroup$

Firstly, just including the map of the ridges, in particular the Lomonosov Ridge and the characteristic bend visible near the North Pole:

enter image description here

Image Source

Based on magnetic anomaly observations, Cochran et al. (2006) theorise that the bend visible in the Lomonosov Ridge formed over a 3-6 million year period where there may have been a non-transform offset connecting a seafloor spreading region in the west Eurasian Basin with the continued continental rifting to the east, that continued propogating eastward resulting in the area of oblique spreading.

According to the Cochran et al. article, the tectonic spreading occurred around 53-56 million years ago, which according to models from Shephard et al. (2013) was associated with the opening of the Eurasia Basin.

Note: Cochran et al. refer to the eastern side as that on the Siberian side of the 'bend' and consequently, the western side being in the direction of North America.

Specifically, Cochran et al. conclude that

The prominent bend in the Lomonosov Ridge near the Pole corresponds to an approximately 50 km offset in Marvin Spur. The offset of the marginal ridge is consistent with the presence of a short extensional segment located between two long transforms.

References

Cochran et al. 2006, Morphology and structure of the Lomonosov Ridge, Arctic Ocean, Geochemistry, Geophysics, Geosystems

Shephard et al. 2013, The tectonic evolution of the Arctic since Pangea breakup: Integrating constraints from surface geology and geophysics with mantle structure Earth-Science Reviews

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.