text: Yo, check it out, let me break it down for you
  The ocean redox state, 2.3 billion years ago, oh so true
  Controversy surrounds this topic, no doubt
  But we got iron isotope evidence to clear it out
  
  The ocean iron cycle changed, can't you see?
  At the same time as the atmospheric redox, it be
  Pyrites older than 2.3 Ga, they got negative iron isotope values
  An iron-rich global ocean, affected by iron oxides, for real
  
  But between 2.3 and 1.8 Ga, things shifted, my friend
  Positive iron isotope values of pyrite, that's the trend
  An increase in iron sulfide precipitation, oh so clear
  Relative to iron oxides, in a redox stratified ocean, no fear