Nodules!

'Below the thunders of the upper deep;
Far, far beneath the abysmal sea,
His ancient, dreamless, uninvaded sleep,
The Kraken sleepeth ..."

Thank you to Alfred, Lord Tennyson for this introduction to the chapter, "Biogeochemical Activity in Deep-Sea Sediments", which, amongst other things, tells us all about manganese nodules. They are formed by authigenesis. At least the top bits are, as they take iron and cobalt from the sea-water (somehow). And the bottom bits (below the sediment) are formed by taking manganese, nickel (?, what is Ni?) and copper from the pore waters. So that is diagenesis. The Indians are exploiting these. Churning up the sediments with enormous suckers and dredgers - all for a few handfuls of metals in a ball.

I'm just about ready to drop. So much to try to take in - but no sooner does it go in, than it slips out again. It's all quite hopeless, I'm afraid! I think I will do a quick wiz through trophic levels and 'Laws' and then wait and see what the fates have in store.

I am determined that, if nothing else, I shall write neatly.