Plate tectonics and carbon dioxide?

[Ontogeny]

I just read an article in New Scientist and there is mention of :...the advent of plate tectonics that help regulate carbon dioxide.

 

Could someone please explain how this correlation comes about?

 

It doesn't make sense to me!

[Mchurd]

More or less there's a correlation.

 

Carbon, which makes up all life, gets laid on the seafloor when marine animals die. The dead animals, some of which have calcium carbonate skeletons, settle on the marine floor and become cemented into sedimentary rock. New sea floor is constantly being made at spreading centers (areas of tectonic plate divergence). The old sea floor is subducted underneath continental crust. Trenches are often the result of subduction zones. Marianas trench is an example. The sedimentary rock, which has carbon in the form of skeletal remains, is buried deap within the crust and eventually makes it to the mantle.

 

I actually just made a blog post on iron fertilization, which starts this process of carbon burial.

http://thescienceofearth.blogspot.com

 

Please respond if it doesn't make sense. I kind of wrote imagining you know basics of geology and oceanography.

[Ontogeny]

Yeah,

thanks for your reply, appreciate it!

 

I do get what you're saying and I thought that might be what was meant, I would have just thought that plate tectonics would not account for a lot of the CO2 in the atmosphere!

 

Cheers

[Mchurd]

Geology is in control of the biggest carbon reservoir on the planet. it dwarfs the carbon available in the atmosphere and oceans.

[Ontogeny]

WOW, thanks for the explanation...I had no idea:doh:

 

I always imagined most CO2 to be produced through the break down of organic matter, ruminants and more recently by us in the form of polution!

 

Plate tectonics never occured to me...you learn every day:D

[Ophiolite]

We need to take the plate tectonics issue further. As the crustal plates are carried into the mantle by subduction at the trenches, temperatures rise. Partial melting of the rocks occurs and magmas are generated which make their way towards the surface where they erupt as in the Andes or the island arcs of Indonesia. Contained within those magmas is a considerable volume of carbon dioxide which is thus recycled back into the atmosphere.

[Ontogeny]

Thanks for your reply, it helped to explain things further

 

Cheers

[Mchurd]

Indeed Ophiolite. Researching into paleoclimate you'd find that hydrothermal vents nad volcanic activity had a much greater influence on the climate than it does today, though.