Final answer:
Entisols are soils of recent origin with unaltered parent material and usually only an A horizon, often found in places like the Rocky Mountains. They have a young soil profile with minimal horizon development and are significantly influenced by their parent material.
Step-by-step explanation:
Soils are classified into different orders based on characteristics such as their horizons and the processes by which they were formed. Entisols are one of these soil orders, and they are defined as soils that have formed in recent times. These soils typically consist of unaltered parent material and usually exhibit no distinct genetic horizons, with the potential exception of an A horizon. Entisols are a diverse group due to the variety of environmental settings in which they can be found, such as the steep, rocky settings of the Rocky Mountains. Given the descriptions provided, Entisols best fit the characteristics of soils that are of recent origin, have unaltered parent material, and often lack developed horizons beyond the A horizon.
The soil profile consists of various layers or horizons, such as the O horizon (organic matter), A horizon (a mix of organic material and inorganic products of weathering), B horizon (accumulation of fine material that has moved downward), and C horizon (soil base with parent material). The A horizon is essential for plant production due to its mixture of organic and inorganic substances and is usually where topsoil is found. Entisols, often lacking well-developed B and C horizons, typically have a more pronounced A horizon, reflecting their youth and limited soil profile development.
Factors that influence soil formation include climate, organisms, relief, parent material, and time. These factors work together to create different soil horizons and characteristics. Entisols, being younger soils, are significantly influenced by the parent material and often lack the mature horizon development seen in older soil profiles.