The global iron industry and the Anthropocene

Iron ore is the most mined metal and the second most mined mineral in the world. The mining of iron ore and the processing of iron and steel increased sharply during the 20th century and peaked at the beginning of the 21st century. Associated processes along the iron ore cycle (mining, processing, recycling, weathering) such as the massive displacement of rock, the emission of waste and pollutants, or the weathering of products resulted in long-term environmental and stratigraphic changes. Key findings link the iron ore industry to 170 gigatons of rock overburden, a global share of CO ₂ with 7.6%, mercury with 7.4%, and a variety of other metals, pollutants, and residues. These global changes led to physical, chemical, biological, magnetic, and sequential markers, which are used for the justification of the Anthropocene. The potential markers vary significantly regarding their persistence and measurability, but key findings are summarised as TMPs (Technogenic Magnetic Particles), SCPs (Spheroidal Carbonaceous fly ash Particles), POPs (Persistent Organic Particles), heavy metals (vanadium, mercury, etc.), as well as steel input and steel corrosion residues.