Yeah, they also found nodules. However, the nodules contain Manganese, the mud contains the rare earths.
http://www.gmanetwork.com/news/scitech/science/649708/japan-team-maps-lsquo-semi-infinite-rsquo-rare-earth-reserves/story/Quote
Japanese researchers have mapped vast reserves of rare earth elements in deep-sea mud, enough to feed global demand on a "semi-infinite basis," according to a fresh study.
The nodules don't contain the rare earths, the mud does. When I originally posted this they had pics of the cores, they took from the mud.
You seems to have confused one thing with another.
3-4 of the articles I linked above, state that they can
easily extract the rare earth from the MUD because the rare earth grains are 4-5 times the size of the mud grains.
Nodules on the other hand are large. Like 4-5 inches or more, in diameter.
When I take the time to link 4-5 articles, you should at least read them. ^^