Ca carbonate transported by subducting slabs could explain elevated ferric iron content in the upper mantle through redox reactions with Fe3+ garnet and graphite as products, according to high-pressure, high-temperature experiments. More detail at https://www.nature.com/articles/s43247-021-00116-8.

The oxidation of volatile organic compounds is a major contributor to atmospheric aerosol, which affects climate and health. The α-pinene and ozone system is particularly efficient in this regard, but how exactly do these two molecules lead to aerosol?

What happens to materials when they are built from squares?