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Lecture 2
Page 1: Introduction
Institution: FIU College of Arts, Sciences & Education
Department: School of Environment, Arts and Society - Department of Earth and Environment
Focus Areas: Organic material, soil formation, soil horizons (A, B, C), and parent material.
Instructor: Professor Dr. Barbara Nogueira Souza Costa, January 2025
Page 2: Learning Objectives
Understand the key factors influencing soil formation
Describe soil-forming processes
Discuss the role of human activity in modifying soil formation
Page 3: Agenda
Overview of concepts related to soil formation
Key factors influencing soil formation
Processes involved in soil formation
Weathering processes and specific soil formation processes
Page 4: Key Concepts
Soil Genesis/Pedology: Phase of soil science focused on factors and processes of soil formation (also known as pedogenesis).
Page 5: Soil Formation
Process Duration: Soil formation is a long-term process, taking several million years to create a thin layer of soil.
Composition: Soil is a complex mixture originating from weathering of parent rocks, referred to as ‘parent materials’.
Factors Influencing Soil Type: Depends on physico-chemical properties of parent rock, weathering intensity and duration, climatic conditions, and other parameters.
Page 6: Origin of Soils
Transporting Forces: Wind, water, and glaciers can influence soil displacement.
Climatic Conditions: Affect the form and rate of physical and chemical weathering, critical to soil formation.
Soil Formation Structure: Involves weathering products, structural development, differentiation into horizons or layers, and movement (translocation).
Page 7: Influencing Factors (CORPT)
CORPT Factors: Climate, Soil, Parent Material, Topography, Plants and Animals, and Time affecting soil formation.
Page 8: Plant Material
Parental material influences mineralogical composition, chemical and physical characteristics.
Types of materials:
Mineral (rocks)
Organic (plant residues)
Page 9: Rock Types
Igneous Rocks: Formed from melted rock; examples include:
Types: Kimberlite, Gabbro, Basalt, Granite, Rhyolite
Characteristics include magma crystallization as it cools.
Page 10: Sedimentary Rocks
Formed from layers of sand, silt, and biological debris.
Examples include:
Types: Glacial, Conglomerate, Shale, Limestone, Sandstone
Page 11: Metamorphic Rocks
Formed under heat and pressure changes.
Examples include:
Types: Schist, Gneiss, Slate, Marble
Page 12: The Rock Cycle
Describes the transformation processes for igneous, sedimentary, and metamorphic rocks, influenced by weathering, pressure, and melting.
Page 13: Methods of Soil Introduction
Movement of soil through:
Gravity: Colluvial
Water: Alluvial, Marine, Lacustrine
Ice and Wind
Page 14: Climate's Role in Soil Formation
Warm & Wet Climates: Accelerate soil formation due to faster weathering and organic matter decomposition.
Cold Regions: Experience slower weathering and decomposition.
Impact of Climate: Affects soil depth, formation, and characteristics.
Page 15: Organisms Impact
Roles of Living Organisms: Includes plants, animals, and humans affect soil characteristics and formation processes.
Page 16: Time Influence
Soil formation can take hundreds to thousands of years.
Younger soils show characteristics of their parent material; aging involves adding organic matter and changing environmental factors.
Page 17: Topography Effects
Terrain Influence:
Deeper soils on flat terrain with distinct horizons.
Shallow soils on slopes due to erosion, resulting in less distinct profiles.
Page 18: Soil Formation Processes
Key Processes:
Additions: Inputs like rain and organic matter.
Losses: Erosion and nutrient leaching.
Translocations: Movement within soils.
Transformations: Changes in soil components.
Page 19: Additions
Examples include:
Rain adds water.
Dust adds minerals.
Animal waste contributes organic matter and nutrients.
Humans may add fertilizers.
Page 20: Losses
Processes include evaporation, erosion, and leaching of nutrients into groundwater.
Page 21: Translocations
Soil movement can be influenced by gravity, evaporation, and organisms transporting materials.
Page 22: Transformations
Soil components change form through:
Decomposition of leaves into humus.
Weathering of hard rock into clay.
Oxidation processes leading to soil color changes.
Page 23: Weathering Processes
Definition: The dissolution and reformation of minerals.
Types include physical, chemical, and biological weathering.
Page 24: Primary vs. Secondary Minerals
Primary Minerals: Direct crystallization from magma (e.g., Quartz, Feldspar).
Secondary Minerals: Formed by alteration/weathering of primary minerals (e.g., Clay minerals).
Page 25: Types of Weathering
Physical Weathering: Mechanical breakdown.
Chemical Weathering: Reactions causing mineral breakdown.
Biological Weathering: Impact of living organisms on rock breakdown.
Page 26: Physical Weathering
Breakdown due to processes like freezing/thawing and wetting/drying.
Page 27: Chemical Weathering
Influences include:
Hydrolysis: Reaction with water.
Oxidation: Reaction of minerals with oxygen.
Carbonation: Reaction with carbonic acid.
Dissolution: Some minerals dissolve in water.
Page 28: Biological Weathering
Caused by living organisms; involves compounds from organic matter and root systems affecting rock.
Page 29: Specific Soil Formation Processes
Physical and chemical properties driven by varying processes of additions, transformations, translocations, and removals.
Page 30: Types of Specific Soil Formation Processes
Examples include: Calcification, Podzolization, Laterization, Gleization, and Salinization.
Page 31: Calcification
Definition: Calcium carbonate accumulation in the soil profile.
Conditions: Semi-arid to arid climates; common in B horizon (calcic horizon).
Page 32: Podzolization
Definition: Leaching of bases creating acidic soils; occurs in cool, humid climates.
Features: Bleached E horizon; iron/aluminum accumulation in B horizon.
Page 33: Laterization
Definition: Tropical weathering leading to iron and aluminum oxide accumulation; results in nutrient-poor soils.
Conditions: Hot, wet climates.
Page 34: Gleization (Hydromorphic)
Definition: Soil waterlogging resulting in bluish-gray colors through iron reduction.
Conditions: Poor drainage situations (wetlands).
Page 35: Salinization
Definition: Accumulation of soluble salts; adverse effects on vegetation present.
Conditions: Typically in arid regions or due to poor irrigation practices.
Page 36: Human Factors in Soil Formation
Actions Influencing Soil: Deforestation, agricultural practices, urbanization, land development.
Page 37: Conclusion
Key Components of Soil: Primarily minerals from weathered parent material.
Thousands of soil types exist classified based on development levels influenced by parent material, climate, organisms, topography, and time.
Distinct properties arise from interactions of soil-forming processes under various environmental conditions.
Page 38: Questions
Open floor for any questions or comments.
FIU College of Arts, Sciences & EducationDepartment: Earth and EnvironmentInstructor: Professor Dr. Barbara Nogueira Souza Costa, January 2025
Learning Objectives
Understand key factors influencing soil formation
Describe soil-forming processes
Discuss human impacts on soil formation
Key Concepts
Soil Genesis/Pedology: Study of soil formation processes.
Soil formation is a long-term process requiring millions of years, influenced by parent materials, climate, organisms, and time (CORPT factors).
Soil Composition and Types
Originates from weathering of parent rocks; affected by mineralogical composition and organic materials.
Rock Types:
Igneous: Formed from cooled magma (e.g., Granite).
Sedimentary: Layers of sand and biological debris (e.g., Limestone).
Metamorphic: Formed under heat/pressure (e.g., Marble).
Weathering and Soil Formation Processes
Weathering: Physical, chemical, and biological processes leading to soil development.
Key processes: Additions, losses, translocations, transformations.
Specific Soil Formation Processes
Includes Calcification, Podzolization, Laterization, Gleization, Salinization, each occurring under differing environmental conditions.
Human Impact
Human activities such as deforestation and urbanization alter soil characteristics and processes.
Introduction
The FIU College of Arts, Sciences & Education, through the Department of Earth and Environment, under the instruction of Professor Dr. Barbara Nogueira Souza Costa in January 2025, focuses on critical aspects of soil formation, organic material, and the concept of soil horizons (A, B, C), alongside parent material.
Learning Objectives
The course aims for students to understand the key factors influencing soil formation, describe soil-forming processes, and discuss the role of human activity in modifying these processes.
Key Concepts
Soil Genesis or Pedology is the phase of soil science dedicated to studying the factors and processes involved in soil formation, also acknowledged as pedogenesis. Soil formation is a lengthy process, often taking several million years to create a thin layer of soil. This complex mixture originates from the weathering of parent rocks, and the resulting soil type is influenced by the physico-chemical properties of these rocks, the intensity and duration of weathering, climatic conditions, and various other parameters.
Soil Formation
Soils are significantly influenced by transporting forces such as wind, water, and glaciers, which play a role in soil displacement. Various climatic conditions impact the rate of physical and chemical weathering essential for soil formation, and the soil formation structure includes weathering products, structural development, differentiation into horizons, and movement (translocation). The CORPT (Climate, Organisms, Parent Material, Topography, and Time) factors have a significant impact on soil formation.
Soil Composition and Types
The parental material is crucial in determining soil mineralogical composition and its chemical and physical characteristics. Soil can be categorized into three main rock types: Igneous rocks, which are formed from melted rock such as granite; Sedimentary rocks, which form from layers of sand and biological debris like limestone; and Metamorphic rocks, which arise under heat and pressure, including examples like marble.
Weathering Processes
Weathering, defined as the dissolution and reformation of minerals, can be classified into three types: physical, chemical, and biological. Physical weathering involves mechanical breakdown, while chemical weathering leads to mineral breakdown through reactions such as hydrolysis and oxidation, and biological weathering is the effect of living organisms on rock decomposition.
Specific Soil Formation Processes
Soil formation processes consist of additions, losses, translocations, and transformations. Examples include calcification, podzolization, laterization, gleization, and salinization, each occurring under specific environmental conditions.
Human Impact
Human activities, including deforestation, agricultural practices, urbanization, and land development, significantly influence soil characteristics and formation processes. As such, the complexity of soil types is largely a reflection of numerous interactions among these formative processes under varying environmental conditions.
