Talk:Oceanic core complex

Formation section needs rewriting

I found this article very much lacking in clarity. If I understand it correctly, these complexes form around a mid-ocean spreading zone which has run dry, meaning it has no more lava creating the normal basaltic/gabro oceanfloor so instead the "normal" mantle is surfacing. I would like to read more about why it runs dry (temperature?), but instead the article focusses on subduction processes which seems totally irrelevant to me (I have a master in geology) in this situation. Codiv (talk) 10:28, 2 April 2026 (UTC)

You're right, it could be clearer. In general, at intermediate, slow and ultra-slow ridges, there are two modes of spreading; volcanic, with the space between the separating plates filled by new volcanic/magmatic material, mostly basalts and gabbros, and detachment faulting, where the space is filled by mantle, basically peridotite, variably serpentinised. Which mode dominates along a particular ridge segment depends on the local magma supply. Magma, not only provides a source for the volcanic material but also changes the strength of the oceanic lithosphere. It seems that magma supply changes both along the ridges and with time. There is also discussion about mantle compositional and thermal heterogeneity. No handy recent review papers have turned up so far in my searches. I will endeavour to improve the article, although I also have several other projects in hand so this may not happen quickly, unless I can come up with something that doesn't involve a major rewrite. Mikenorton (talk) 12:17, 3 April 2026 (UTC)

Thanks for your fast responce! The matter is still very much a subject of scientific research I understand. Well, let's hope we have some better understanding of these matter in the years to come. Maybe permeability is als an item here, if I remember correctly the mantle is only able to provide enough magma if certain permeablity parameters are met, mainly depending of the shape of the surrounding minerals. But I have no idea why they should vary over time. Codiv (talk) 16:56, 3 April 2026 (UTC)

Something else to consider is the effect of mantle upwellings ("plumes") O'Connor et al. 2018, whose effects can apparently spread over a wide area. This certainly comes close to "permeability", with "rapid" (in plate tectonic terms) lateral movement of hot material through the asthenosphere. Mikenorton (talk) 09:48, 7 April 2026 (UTC)