Elements Covers

Posts by Martin Reich

Nitrate Deposits of the Atacama Desert: A Marker of Long-Term Hyperaridity

The nitrate deposits of the Atacama Desert are unique when one considers that in most surface environments nitrate is produced or consumed by biological processes and is easily washed away by rain. Nitrate deposits have puzzled geologists since Charles Darwin’s visit to the Atacama in 1835 and several hypotheses have been proposed to explain their origin. Here, we review our current understanding of the nitrate deposits in the Atacama Desert and show that nitrate’s primary origin is predominantly atmospheric. However, its massive accumulation and preservation specifically in Atacama is due to the serendipitous convergence of climatic, tectonic and hydrologic conditions that are unique to the Central Andes.

Read More

The Central Andes: Elements of an Extreme Land

The Central Andes and the Atacama Desert represent a unique geological, climatic, and magmatic setting on our planet. It is the only place on Earth where subduction of an oceanic plate below an active continental margin has led to an extensive mountain chain and an orogenic plateau that is second in size only to the Tibetan Plateau, which resulted from continental collision. In this article, we introduce the history of the Central Andes and the evolution of its landscape. We also discuss links between tectonic forces, magmatism, and the extreme hyperarid climate of this land that, in turn, has led to rich deposits of precious ores and minerals.

Read More