Editorials

This issue of Elements explores the fascinating realm of deep-ocean deposits that have the potential to provide society with many of the raw mineral resources required to meet the world’s growing needs. While raw materials have always, and always will, play a critical role in meeting these demands, materials made by humans have also become increasingly important, expanding in concert along with the world’s population, industry, and resource use. Most notably, plastics, which are synthetic organic polymers derived from fossil hydrocarbons, have become an indispensable part of our material world because of their remarkable number of uses and versatility. Plastic bottles, bags, credit cards, scotch tape, pipes, toys, to name a few, form part of our everyday life. Not surprisingly, the global production of plastic has increased from 2 metric tons (Mt) in 1950 to 380 Mt in 2015 (Geyer et al. 2017). By 2050, Geyer et al. (2017) estimate that roughly 12,000 Mt of plastic waste will be in the natural environment. This is a staggering amount, enough to cover the entire surface of the Earth in a thin layer of plastic! With the growing abundance of plastic, the potential for preservation in the rock record increases. What impact will synthetic materials like plastic have on future deposits in the Earth – will there be a “Plasticene Epoch”?

The Central Andes is a land of llamas, salt flats and majestic volcanic peaks. It is one of most remote places on Earth and arguably the driest. In a not unconnected way, the Central Andes is also home to the world’s largest copper mines. The unique combination of magmas, tectonics and climate, described in this issue of Elements, has conspired to create hydrothermal ore deposits that provide a third of the world’s copper and a quarter of its molybdenum.

As we set up the publication schedule for each year, the principal editors of Elements try to ensure that the journal maintains enough diversity to hold the interest of you, our readers. In this context, we sometimes accept proposals for issues on very well-known mainstream subjects (such as layered intrusions) which we think can usefully be updated and summarised at a good level. We also try, however, to bring you subjects which are outside the mainstream yet still can be grouped loosely within the areas of geochemistry, mineralogy and petrology. That is how we categorise the current issue dealing with the environmental aspects of making high-quality wine.