Introduction

Abstract

Denudation, volcanism, and tectonics are intertwined Earth system processes that constitute the main driving forces intervening in shaping the Earth’s landscape. Clearly, the wearing away of the Earth’s surface cannot occur unless a series of synergistic processes, collectively known as “weathering,” are initiated. This term, in use for a long time, promotes the idea that climate (weather) always plays a major role in rock breakdown; since this is not the case in every instance the change for “rock decay” has been proposed recently. At any rate, the linkage between weathering and denudation is not straightforward because the latter may be limited by the former (“weathering-limited denudation”) or, in contrast, it may be restricted by the hindered transport of the weathering-produced debris (“transport-limited denudation”). In addition to these possible scenarios, two new approaches have been gaining growth in the recent past: one is the study of the “regolith” as a convenient research framework, and the other is the notion of “the critical zone,” where the dynamic interaction with the atmosphere and vegetation is emphasized and added to the materials collectively defined as regolith.

Glossary

Aeolian deposit:

Fine sediments transported and deposited by wind. Loess, dunes, desert sand, and some volcanic ash are included in this category.

Alluvium:

Material deposited by rivers, usually forming floodplains and deltas, which is typically most extensively developed in the lower part of the course of a river; consists of silt, sand, clay, and gravel and often with a significant proportion of organic matter.

Colluvium:

Soil and debris that accumulate at the base of a slope by mass wasting or sheet erosion. It usually includes unsorted angular fragments, and may contain slabs of bedrock that indicate both their place of origin and that slumping was the process of transportation. At the edges of valleys, colluvium may be mixed with and almost indistinguishable from alluvium.

Critical zone:

It is the zone critical for the sustenance of life on Earth, which encompasses the lowermost groundwater to the atmosphere that meets the Earth; it is the zone where the lithosphere intersects with the biosphere, hydrosphere, and atmosphere.

Evaporitic sediment:

Sediment soluble in water that results from concentration and crystallization by evaporation from an aqueous solution. Marine and non-marine are the types of evaporate deposits. The latter are found in standing bodies of water such as lakes (playas).

Regolith:

Layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestrial planets and moons.

Saprolite:

Is a chemically weathered bedrock surface, found in the lower zones of soil profiles. Deeply weathered profiles are widespread on continental landmasses, between 35° N and 35° S.