Exc pic of chalk as per White Cliffs of Dover … coccolithophores.
A man that is fascinated with such things and he too talks of diatoms – a vast genus that will prove so crucial to this planets unfortunate demise as we know it, for instance symbiosis with coral reef ie Bryozoans and its the exploitationof ancient oil and gas from diatoms ( 70% originates from diatoms) that with cruel irony is our demise. Diatoms produce DMS a gas discovered by James Lovelock in the 1970’s that is fundamental in weather systems / cloud formation out in the oceans, likewise diatoms provide 20% of the worlds CO2 to O conversion. And invisible to the naked eye. No expensive microscope, a secondhand students microscope set to low mag ie x100 will do all you want.
and from the above wiki we get a link to DMS …. https://en.wikipedia.org/wiki/Dimethyl_sulfide
Interesting to see Lynn Margulis, i have a most fascinating book here, beautifully illustrated bought say twenty years ago ‘What is Life’ exploring the ideas of Ernst Shrodinger and his book of three quarters of a century ago. Note Sagan as in wife of Carl.
Another book, important and packed with knowledge is James Lovelock ‘Gaia’ a most incredible Independant Scientist, i’ve also his autobiography a very interesting read, easy too. But the Gai I have here suffers from too much colour in its explanations, more confusing than helpful in many cases. Never mind, i’m sure James Lovelock can hardly be held responsible once the publishers get their hands on it.