Earth Science: Erosion, Soil, Rock and Carbon Cycles

Posted on Jan 30, 2025 in Geology

Erosion

Erosion is the set of exogenous phenomena, outside the area, whose actions contribute to or modify the forms created by internal and endogenous processes.

Weathering

Weathering includes the disintegration and decomposition of rocks that originate in the same place that later became sediments. Weathering rates:

  • Oceanic: It consists in the destruction of rocks by physical processes.
  • Chemical: It consists in the destruction of rocks by the action of the solvent water.

Sea Modeling

Sea modeling results from the erosive action of the waves, tides, and sea currents on coasts, with the help of the materials in suspension that they often drag.

Soil

Soil is the outermost layer of the continental crust, formed as part of the alteration produced on the surface rocks by the action of various agents. It is composed of a mineral fraction and an organic fraction.

Texture and Structure of Soil

  • Texture: The proportion of sand, lime, and clay.
  • Structure: The way the various constituent particles connect.

Soil Classification

  • Estirosoles: No horizons, sandy and thin.
  • Inceptisols: Perennial soil.
  • Vertisols: Alluvial soils with clay.
  • Mollisols: Soils with abundant humus.
  • Alfisols: Moderately developed soils.
  • Altisoles: Quite developed soils.
  • Oxisols: Old soils.
  • Hestorales: Cerragosa areas soils.

Rock Cycle

The rock cycle is a sequence of processes through which the materials composing the Earth’s solid element can move from one rock type to another.

Phases

  1. The igneous magma forms.
  2. The igneous rock is degraded into small particles.
  3. The particles are swept away by erosion and stored as sediments.
  4. Sediments form sedimentary rock through lithification.
  5. The sedimentary rocks are transformed by atmospheric pressure into metamorphic rocks.
  6. Metamorphic rocks melt and become magma.

Carbon Cycle

The carbon cycle is the main source of carbon for living things. Carbon is incorporated into organic matter by producers in the process of photosynthesis and returned to the atmosphere in the processes of respiration.

Landforms

  • Moraine: A moraine is a blanket of till deposited by a glacier.
  • Delta: A delta is the triangular area formed at the mouth of a river, through sediments deposited as the stream disappears.
  • Meanders: Meanders are curves traced by the course of a river, which are pronounced sinuosity.
  • Cliff: A cliff is a geographical accident that consists of a steep or vertical slope.
  • Dunes: Dunes are accumulations of sand caused by the action of wind and set around an obstacle.

Rock Types

  • Igneous Rocks: Rocks formed by the cooling and solidification of magma.
  • Metamorphic Rocks: Rocks formed by pressure and high temperatures.
  • Sedimentary Rocks: Rocks formed by the accumulation of sediments, subjected to physical and chemical processes, resulting in a material of some consistency.

Humus

Humus is a substance composed of organic, colloidal material, which comes from the decomposition of organic debris.

Arboreal

A tree is a plant with a woody trunk, which branches off the ground.

Review of Soil Formation

Soils: In the Earth and life sciences, soil is the structured, biologically active system that tends to develop on the surface of the land by the influence of weather and living things. In a simplified way, the steps involved in its formation are:

  • Fragmentation of rock mechanics.
  • Weathering chemistry of regolith materials to be released.
  • Installation of living things (plants, microorganisms, etc.) on the inorganic substrate. This is the most significant phase, as with its metabolic processes of life, it continues the weathering of minerals initiated by inorganic mechanisms. In addition, the remains of plants and animals, through fermentation and putrefaction, enrich the substrate.
  • A mixture of all these elements together, and with water and interstitial air.