Weathering is the ubiquitous hallmark of the interaction of rock with environmental conditions on Earth’s surface. Alteration of fresh rock both releases nutrients to organisms and consumes atmospheric CO2. The disaggregated products of weathering provide substrate to anchor roots, and their production is the first step in sculpting landscapes. The porosity structure developed by weathering retains water and paces its flow back to the oceans. For all these reasons, we care a great deal about the rates of weathering, how deeply below the surface a rock is weathered, and if this zone of weathering is steady or changing in time.
Anderson, S.P. (2012): How deep and how steady is the Earth’s surface? . Geology, 40 (9): 863-864. DOI: 10.1130/focus092012.1