Weathering
Introduction
Weathering is the breakdown and alteration of rocks and minerals at or near the Earth's surface into products that are more in equilibrium with the conditions found in this environment. Most rocks and minerals are formed deep within the Earth's crust where temperatures and pressures differ greatly from the surface. Because the physical and chemical nature of materials formed in the Earth's interior are characteristically in disequilibrium with conditions occurring on the surface. Because of this disequilibrium, these materials are easily attacked, decomposed, and eroded by various chemical and physical surface processes.
Weathering is the first step for a number of other geomorphic and biogeochemical processes. The products of weathering are a major source of sediments for erosion and deposition. Many types of sedimentary rocks are composed of particles that have been weathered, eroded, transported, and terminally deposited in basins. Weathering also contributes to the formation of soil by providing mineral particles like sand, silt, and clay. Elements and compounds extracted from the rocks and minerals by weathering processes supply nutrients for plant uptake. The fact that the oceans are saline in the result of the release of ion salts from rock and minerals on the continents. Leaching and runoff transport these ions from land to the ocean basins where they accumulate in seawater. In conclusion, weathering is a process that is fundamental to many other aspects of the hydrosphere, lithosphere, and biosphere.
There are three broad categories of mechanisms for weathering: chemical, physical and biological.
Products of Weathering
The process of weathering can result in the following three outcomes on rocks and minerals:
(1). The complete loss of particular atoms or compounds from the weathered surface.
(2). The addition of specific atoms or compounds to the weathered surface.
(3). A breakdown of one mass into two or more
Weathering is the breakdown and alteration of rocks and minerals at or near the Earth's surface into products that are more in equilibrium with the conditions found in this environment. Most rocks and minerals are formed deep within the Earth's crust where temperatures and pressures differ greatly from the surface. Because the physical and chemical nature of materials formed in the Earth's interior are characteristically in disequilibrium with conditions occurring on the surface. Because of this disequilibrium, these materials are easily attacked, decomposed, and eroded by various chemical and physical surface processes.
Weathering is the first step for a number of other geomorphic and biogeochemical processes. The products of weathering are a major source of sediments for erosion and deposition. Many types of sedimentary rocks are composed of particles that have been weathered, eroded, transported, and terminally deposited in basins. Weathering also contributes to the formation of soil by providing mineral particles like sand, silt, and clay. Elements and compounds extracted from the rocks and minerals by weathering processes supply nutrients for plant uptake. The fact that the oceans are saline in the result of the release of ion salts from rock and minerals on the continents. Leaching and runoff transport these ions from land to the ocean basins where they accumulate in seawater. In conclusion, weathering is a process that is fundamental to many other aspects of the hydrosphere, lithosphere, and biosphere.
There are three broad categories of mechanisms for weathering: chemical, physical and biological.
Products of Weathering
The process of weathering can result in the following three outcomes on rocks and minerals:
(1). The complete loss of particular atoms or compounds from the weathered surface.
(2). The addition of specific atoms or compounds to the weathered surface.
(3). A breakdown of one mass into two or more