p.1
Types of Folds in Geology
What are isoclinal folds?
Folds formed when compressive forces make both limbs parallel but not horizontal.
p.1
Types of Folds in Geology
What characterizes recumbent folds?
Both limbs of the fold become parallel and horizontal due to strong compressive forces.
p.1
Types of Folds in Geology
What are overturned folds?
Folds where one limb is thrust upon another due to intense compressive forces.
p.2
Types of Folds in Geology
What are plunge folds?
Folds where the axis is tilted, forming a plunge angle with the horizontal plane.
p.2
Types of Folds in Geology
What is the plunge angle?
The angle between the axis of the fold and the horizontal plane.
p.2
Types of Folds in Geology
What do fan folds consist of?
Several minor anticlines and synclines, resembling a fan.
p.2
Types of Folds in Geology
What characterizes open folds?
The angle between the two limbs of the fold is more than 90 degrees.
p.4
Types of Folds in Geology
What are closed folds?
Folds where the angle between the two limbs is an acute angle.
p.4
Types of Folds in Geology
What causes closed folds to form?
Intense compressive force.
p.6
Exogenetic Forces and Weathering Processes
What are exogenetic forces also known as?
Denudational processes or destructional forces.
p.38
Mass Movement and Its Classification
What factors accelerate mass movement?
The presence of water, ice, and air.
p.29
Types of Weathering: Physical, Chemical, and Biological
What does the term 'chelate' refer to?
A co-ordination compound in which a central metallic ion is attached to an organic molecule at two or more positions.
p.56
Soil Atmosphere and Its Importance
What is the soil atmosphere?
The gases found in soil profiles, forming an important component of the soil.
p.116
Clay Minerals and Their Characteristics
What interlayer cations are found in illites?
1. Na, 2. K, 3. Mg, 4. Fe.
p.124
Soil Water and Its Role in Plant Growth
Why is hydrogeology increasingly relevant in India?
Due to overexploitation, declining groundwater levels, and groundwater quality issues affecting the population.
p.124
Soil Water and Its Role in Plant Growth
What is critical for the welfare of mankind regarding hydrogeology?
A good understanding and successful application of hydrogeology by practitioners.
p.103
Soil Composition and Formation
How does an imbalance in the ratio of cations affect surface soil horizons?
It results in poor soil structure.
p.43
Mass Movement and Its Classification
What are the criteria for identifying types of mass movement of rock waste?
Based on direction and type of movement.
p.44
Mass Movement and Its Classification
What are the three types of slides in mass movement?
Rock slides, debris slides, and earth slides.
p.27
Types of Weathering: Physical, Chemical, and Biological
What is hydration in the context of chemical weathering?
The process of adding water to minerals, causing an increase in volume.
p.103
Soil Composition and Formation
What major issues arise from high sodium levels in soil?
They negatively affect the physical properties of soil.
p.81
Soil Composition and Formation
How is bulk density defined?
The dry weight of unit volume of soil inclusive of pore spaces.
p.132
Soil Water and Its Role in Plant Growth
What is condensational water?
The prime source that replenishes groundwater in deserts and semi-desert areas.
p.8
Soil Texture and Stability
What is the correct sequence of soil texture classes in decreasing order of stability of wet clods?
B, E, A, C, D (Clay, Clay Loam, Loam, Sandy Loam, Silt Loam).
p.60
Soil Water and Its Role in Plant Growth
What role does soil water play in plant growth?
It is essential for plant growth.
p.72
Soil Composition and Formation
What types of soils are formed through hydromorphic profile development?
Swamp, bog, marsh, and peat soils.
p.64
Soil Water and Its Role in Plant Growth
What is the term for the amount of water needed to reach field capacity from the wilting point?
Available water capacity.
p.44
Mass Movement and Its Classification
What is a slump in mass movement?
A type of slide that includes rock slump, debris slump, and earth slump.
p.20
Types of Folds in Geology
What is sheeting in geology?
The development of cracks and fractures parallel to the ground surface due to the removal of superincumbent load.
p.20
Types of Folds in Geology
What causes the development of sheeting?
Reduction of confining pressure from the removal of superincumbent load.
p.113
Clay Minerals and Their Characteristics
What are clay minerals primarily composed of?
Silica, alumina, and water.
p.50
Soil Composition and Formation
What is organic matter in soil primarily derived from?
Dead remains of plants and animals or metabolic activities of living organisms.
p.72
Soil Composition and Formation
What conditions lead to the formation of hydromorphic soils?
Restricted percolation and saturation of certain horizons with water.
p.17
Factors Affecting Weathering
What happens to particles in crystalline rocks when temperature changes?
They expand and contract with increases and decreases in temperature, respectively.
p.123
Soil Composition and Formation
Why is hydrogeology considered complex?
Due to the infinitely complex subsurface geologic environment.
p.87
Soil Composition and Formation
What are some other inorganic compounds found in soil?
Boron, magnesium, copper, zinc, molybdenum, cobalt, iodine, and fluorine.
p.44
Mass Movement and Its Classification
What are the three types of falls in mass movement?
Rock fall, debris fall, and earth fall.
p.82
Soil Composition and Formation
What does bulk density take into account?
Both the solids and the pore space.
p.38
Mass Movement and Its Classification
What is mass movement?
The detachment and downslope transport of soil and rock material under the influence of gravity.
p.60
Soil Water and Its Role in Plant Growth
How do plants primarily absorb water?
Most water is absorbed from the soil.
p.27
Types of Weathering: Physical, Chemical, and Biological
What happens to the volume of rocks after they absorb water?
The volume increases remarkably, sometimes doubling the original volume.
p.71
Soil Composition and Formation
What is calcification?
The accumulation of soluble materials and deposition of carbonates of calcium and magnesium in the B horizon of soil.
p.95
Soil Composition and Formation
What are crystalloids?
Crystalline solid substances that form true solutions when mixed with other substances.
p.56
Soil Atmosphere and Its Importance
What do pore spaces in soil contain?
Moisture and air in varying quantities.
p.30
Types of Weathering: Physical, Chemical, and Biological
What are the three types of biological weathering?
Faunal weathering, floral weathering, and anthropogenic weathering.
p.130
Soil Water and Its Role in Plant Growth
What is meteoric water?
Water derived from precipitation, such as snow and rain.
p.124
Soil Water and Its Role in Plant Growth
What does the term Geo-Hydrology describe?
The same physical processes as hydrogeology.
p.67
Soil Composition and Formation
What are the fundamental processes involved in soil formation?
The development of soil profile.
What are the three types of hexose sugars mentioned?
Glucose, Galactose, Mannose.
p.97
Soil Composition and Formation
What is a colloidal suspension of liquid in liquid?
An example is milk, where fats are suspended in water.
p.128
Soil Water and Its Role in Plant Growth
What is the surface called where water pressure equals atmospheric pressure?
Phreatic level or water table.
p.41
Mass Movement and Its Classification
What type of mass movement involves slow movement with little water required?
Flowage or slide, including rock creep, soil creep, and solifluction.
p.29
Types of Weathering: Physical, Chemical, and Biological
What does chelation involve?
Holding of an ion, usually a metal, within a ring structure of organic origin.
p.125
Soil Water and Its Role in Plant Growth
What is groundwater?
Water present in the pore spaces of regolith and bedrocks below the ground surface.
p.60
Soil Water and Its Role in Plant Growth
Why is soil water considered a good solvent for minerals?
It helps in making the concentration of nutrients low for easier absorption by plants.
p.41
Mass Movement and Its Classification
What type of mass movement requires enough water and occurs rapidly?
Earthflow, mudflow, and sheetwash.
p.106
Soil Composition and Formation
What types of ions can be added to soil for cation exchange?
Cations such as Ca++, K+, and NH3.
p.17
Factors Affecting Weathering
How do temperature changes affect clastic sedimentary rocks?
They are least affected because particles are separated by thin cementing laminae of silica.
p.81
Soil Composition and Formation
What is particle density in soil?
The density of the solid portion of soil, which is the sum total of densities of individual organic and inorganic particles.
p.113
Clay Minerals and Their Characteristics
How are clay minerals formed?
From the weathering and alteration of silicate minerals.
p.97
Soil Composition and Formation
What is an example of a colloidal suspension of solid in liquid?
Clay suspension in water.
p.30
Factors Affecting Weathering
What roles do biotic communities play in weathering?
They play roles in all types of weathering across various climatic regions.
p.16
Types of Weathering: Physical, Chemical, and Biological
What are the three types of weathering agents?
Physical, chemical, and biological weathering agents.
p.27
Types of Weathering: Physical, Chemical, and Biological
Is hydration an endothermic or exothermic reaction?
Hydration is an exothermic reaction.
p.125
Soil Composition and Formation
What materials lie over bedrock?
Regolith, which consists of loose and unconsolidated materials.
p.87
Soil Composition and Formation
How does the chemical composition of soil vary?
It varies in soils of different places and between different horizons.
p.80
Soil Composition and Formation
What is the definition of soil density?
The mass per unit volume of soil.
p.38
Mass Movement and Its Classification
What influences the sliding or flowing of materials in mass movement?
Their position and gravitational forces.
p.6
Exogenetic Forces and Weathering Processes
What activities are involved in exogenetic forces?
Weathering, erosional, and depositional activities.
p.106
Soil Composition and Formation
What happens to cations when they are added to soil?
They are adsorbed on the surface of colloid micelles, replacing other ions.
p.99
Soil Composition and Formation
What are the characteristics of a Mollic horizon?
Thick, dark colored, high base saturation, strong structure.
p.82
Soil Composition and Formation
What is bulk density?
The dry weight of soil per unit volume of soil.
p.29
Types of Weathering: Physical, Chemical, and Biological
What is chelation according to D.S. Lehman?
A complex organic process by which metallic cations are incorporated into hydro-carbon molecules.
p.18
Exogenetic Forces and Weathering Processes
What is granular disintegration?
The shattering of rocks into smaller particles due to temperature changes.
p.95
Soil Composition and Formation
What are the two types of substances in soil particles?
Crystalloids and colloids.
p.34
Factors Affecting Weathering
What is anthropogenic weathering?
Weathering accelerated by human activities, such as deforestation.
p.113
Clay Minerals and Their Characteristics
What is a key structural characteristic of clay minerals?
They have a sheet-like structure composed of layers of tetrahedrons and octahedrons.
p.41
Mass Movement and Its Classification
What are the three types of slow mass movement?
Rock creep, soil creep, and solifluction.
p.18
Exogenetic Forces and Weathering Processes
What role does insolation play in granular disintegration?
Different parts of the same rock mass absorb insolation differently, leading to differential expansion and contraction.
p.51
Soil Composition and Formation
What are the chief elements found in humus?
Carbon, hydrogen, oxygen, sulphur, and nitrogen.
p.18
Exogenetic Forces and Weathering Processes
Why do different colors of coarse-grained rocks affect their disintegration?
Because they absorb insolation differently, causing varying degrees of expansion and contraction.
p.128
Soil Water and Its Role in Plant Growth
What is the pressure head in the unsaturated zone?
It refers to the pressure exerted by water in the unsaturated zone.
p.11
Types of Weathering: Physical, Chemical, and Biological
In which regions is rock disintegration more effective?
In hot and dry regions and where frost action is dominant.
p.56
Soil Atmosphere and Its Importance
How does moisture content in dry soils compare to wet soils?
The percentage of moisture is less in dry soils than in wet soils.
p.131
Soil Composition and Formation
What happens to the contents of magma as it cools?
Gaseous and vapor contents separate out.
p.107
Soil Composition and Formation
What is cation exchange in soil?
The process where cations in soil solutions exchange with those on the surface of soil colloids.
p.115
Clay Minerals and Their Characteristics
What type of clay mineral is Illite?
A 2:1 type of clay mineral with a higher proportion of potassium ions.
p.31
Biological Weathering
How do burrowing animals affect rocks and geomaterials?
They dig out burrows and tunnels, which leads to weathering.
p.42
Mass Movement and Its Classification
What are the criteria for identifying types of mass movement of rock waste?
Based on direction and type of movement.
p.103
Soil Composition and Formation
What is the effect of excessive exchangeable sodium on soil aggregates?
It causes soil aggregates to disperse into individual soil particles, a process known as deflocculation.
p.30
Types of Weathering: Physical, Chemical, and Biological
What is biological weathering?
The breakdown of rocks largely controlled by plants and animals, including humans.
p.123
Soil Composition and Formation
What does hydrogeology study?
The occurrence and movement of water in subsurface geologic environments.
p.71
Soil Composition and Formation
In which regions does calcification commonly occur?
Subhumid and dry regions.
p.88
Soil Composition and Formation
What does the organic component of soil consist of?
Substances of organic origin; living and dead.
p.73
Soil Texture and Stability
What does soil texture refer to?
The size and arrangement of soil particles.
p.47
Soil Composition and Formation
What does edaphology study?
The influence of soil on plants and human beings.
p.34
Mass Movement and Its Classification
What forms can mass movement take as a result of anthropogenic weathering?
Landslides, slumping, and debris fall and slides.
p.63
Soil Water and Its Role in Plant Growth
What replaces water lost from the soil surface by evaporation and absorption by plants?
Rise of capillary water from the root zone.
p.95
Soil Composition and Formation
What is the state of colloids?
Amorphous state that does not form true solutions when mixed with other substances.
p.21
Types of Weathering: Physical, Chemical, and Biological
What is boulder cleaving?
The breaking and splitting of boulders of granites and basalts due to thermal expansion.
p.55
Soil Composition and Formation
What role does humus play in soil fertility?
It makes the soil fertile.
p.30
Types of Weathering: Physical, Chemical, and Biological
What is anthropogenic weathering?
Weathering caused by human activities.
p.51
Soil Composition and Formation
Why is humus considered a dynamic product?
Because it is constantly changing due to oxidation, reduction, and hydrolysis.
p.17
Factors Affecting Weathering
Which type of rocks are more affected by temperature changes?
Crystalline rocks, like granites.
p.47
Soil Composition and Formation
What is the origin of the word 'soil'?
It comes from the Latin word 'solum', which means 'floor'.
p.18
Exogenetic Forces and Weathering Processes
How do coarse-grained rocks react in hot deserts?
They are more affected by the shattering process due to high daily temperature ranges.
p.11
Factors Affecting Weathering
What factors affect the nature and magnitude of weathering?
Agents of weathering, lithological and structural characteristics of rocks, height and slope factors.
p.97
Soil Composition and Formation
What is a colloidal suspension of solid in gas?
An example is smoke, where coal particles are suspended in air.
p.131
Soil Composition and Formation
Where does juvenile water originate?
In the earth’s interior, associated with magmatic activities.
p.73
Soil Texture and Stability
What are the main physical properties of soil?
Color, texture, structure, density, and porosity.
p.123
Soil Composition and Formation
Can the basic principles of hydrogeology be easily understood?
Yes, many basic principles and methods can be readily understood.
p.113
Clay Minerals and Their Characteristics
What results in the unique physical and chemical properties of different clay minerals?
Their different chemical composition and structure.
p.108
Soil Composition and Formation
What happens during the exchange of ions in soil?
It continues until equilibrium is attained.
p.13
Factors Affecting Weathering
What processes are involved in weathering?
Disintegration and decomposition of rocks.
p.73
Soil Composition and Formation
How does mineral composition affect soil properties?
It influences the color, texture, and structure of the soil.
p.83
Soil Composition and Formation
What factors can cause variation in soil particle density?
The presence of different constituents.
p.106
Soil Composition and Formation
What occurs when KCl solution is added to a colloid micelle with Ca++ and H+ ions?
K+ ions replace Ca++ and H+ ions, forming CaCl and HCl.
p.73
Soil Texture and Stability
What is the significance of soil density?
It affects the weight and compaction of the soil.
p.15
Factors Affecting Weathering
Why is climate considered an important factor in weathering?
It influences the type and effectiveness of weathering processes.
p.31
Biological Weathering
What role do small organisms play in rock and soil weathering?
They mix up soil materials and expose fresh materials to weathering agents.
p.66
Soil Composition and Formation
What characterizes the A horizon in a soil profile?
It is the topsoil layer, rich in minerals and organic material.
p.115
Clay Minerals and Their Characteristics
What is one use of Illite?
As a drilling mud additive.
p.10
Types of Weathering: Physical, Chemical, and Biological
According to C.D. Oilier, what is weathering?
The breakdown and alteration of minerals near the earth's surface to products in equilibrium with new physico-chemical conditions.
p.117
Clay Minerals and Their Characteristics
What creates a negative charge in the layer structure of Illite minerals?
The presence of Al 3+ occupying tetrahedral sites.
p.19
Types of Weathering: Physical, Chemical, and Biological
What causes the outer shells of rocks to become loose during exfoliation?
Alternate expansion and contraction due to temperature changes.
p.21
Types of Weathering: Physical, Chemical, and Biological
In which areas is salt weathering important?
In hot arid areas and coastal regions.
p.70
Soil Composition and Formation
What is laterisation?
The process where organic matter and minerals are leached away in tropical and subtropical regions, resulting in the precipitation of aluminium and iron hydroxides as laterite.
p.45
Mass Movement and Its Classification
What are the three types of topples?
Rock topples, debris topples, and earth topples.
p.50
Soil Composition and Formation
What happens to the dead remains of plants and animals in the soil?
They are acted upon by microorganisms and decomposed into simple organic compounds.
p.70
Soil Composition and Formation
What happens to silica during laterisation?
Silica is completely removed.
p.32
Types of Weathering: Physical, Chemical, and Biological
What are the two ways in which floral weathering occurs?
Physical weathering and biochemical weathering (chemical weathering).
p.6
Exogenetic Forces and Weathering Processes
What do exogenetic forces continuously engage in?
The destruction of relief features created by endogenetic forces.
p.96
Soil Composition and Formation
In what form are colloids found?
In aggregates of atoms or molecules, not in ionic or molecular form.
p.132
Soil Water and Its Role in Plant Growth
What happens to atmospheric water vapor as it penetrates rocks?
It gets converted into water through condensation due to falling temperature.
p.71
Soil Composition and Formation
What is a characteristic of pedocals?
They are not acidic and have a very high calcium content.
p.41
Mass Movement and Its Classification
What is the difference between earthflow and mudflow?
Earthflow is a slower movement of saturated soil, while mudflow is a rapid flow of water and debris.
p.75
Soil Texture and Stability
What is soil texture?
A combination of sand, silt, and clay particles in relative proportions.
p.36
Types of Weathering: Physical, Chemical, and Biological
How do fulvic acids contribute to weathering?
They play an important role in decomposing rock minerals.
p.28
Types of Weathering: Physical, Chemical, and Biological
What are the end products of the hydrolysis of potassium feldspar?
Potassium and bicarbonate ions in solution.
p.98
Soil Composition and Formation
What are the two types of gels that sols can form?
Reversible gel and irreversible gel.
p.37
Types of Weathering: Physical, Chemical, and Biological
Which organisms are commonly involved in biological weathering?
Plants, animals, and microorganisms.
p.51
Soil Composition and Formation
Does humus have a definite chemical composition?
No, it has no definite chemical composition.
p.100
Soil Composition and Formation
What does Calic horizon accumulate?
Calcium carbonate (CaCO3) or a mixture of CaCO3 and MgCO3.
p.7
Exogenetic Forces and Weathering Processes
How is weathering defined in the context of denudation?
As a static process involving the disintegration and decomposition of rocks in situ.
p.88
Soil Composition and Formation
What are formed from the original residues during decomposition?
A number of different organic products or compounds.
p.22
Types of Weathering: Physical, Chemical, and Biological
How does acid rain contribute to chemical weathering?
It reacts with minerals in rocks, leading to their dissolution and alteration.
p.48
Soil Composition and Formation
How is soil formed?
By the weathering of rocks and erosion.
p.75
Soil Texture and Stability
Which organizations have established size limits for soil particles?
USDA, BSI, ISSS, and the European system.
p.69
Soil Composition and Formation
In which climate zones does podzolisation primarily occur?
In temperate zones that are cold and moist.
p.53
Soil Composition and Formation
What is found in the duff layer?
Partially decomposed organic matter.
p.37
Types of Weathering: Physical, Chemical, and Biological
Can animals contribute to biological weathering?
Yes, through burrowing and feeding activities that disturb soil and rock.
p.115
Clay Minerals and Their Characteristics
What is one use of Chlorite?
As a drilling mud additive.
p.68
Soil Composition and Formation
What type of layer develops during the Gleization process?
A compact structureless and sticky surface layer.
p.87
Soil Composition and Formation
What are the chief inorganic constituents of soils?
Aluminium, silicon, calcium, magnesium, iron, potassium, and sodium.
p.32
Types of Weathering: Physical, Chemical, and Biological
What is floral weathering?
Weathering of rocks by vegetation.
p.81
Soil Composition and Formation
In what units is bulk density expressed?
In grams per milliliter (gm/ml) or pounds per cubic foot.
p.106
Soil Composition and Formation
What is cation exchange in soil?
The process where positive ions (cations) are attracted and held by negatively charged soil colloids.
p.108
Soil Composition and Formation
What is the nature of exchange reactions in soil?
They are very quick and reversible.
p.24
Types of Weathering: Physical, Chemical, and Biological
What is the process of oxidation in chemical weathering?
A reaction of atmospheric oxygen to form oxides.
p.71
Soil Composition and Formation
What type of soil is formed through calcification?
Pedocal (calcium accumulating soil).
p.104
Soil Composition and Formation
What defines a sodic soil?
It contains a high level of sodium relative to other exchangeable cations.
p.27
Types of Weathering: Physical, Chemical, and Biological
What is a significant consequence of hydration in rocks?
It involves a considerable volume change.
p.31
Biological Weathering
Which animals are known to contribute to faunal weathering?
Gophers, prairie dogs, foxes, rabbits, jackals, termites, and rats.
p.87
Soil Composition and Formation
What does the term 'horizon' refer to in soil science?
Different layers of soil with varying chemical compositions.
p.104
Soil Composition and Formation
What is the threshold for a soil to be considered sodic?
When the Exchangeable Sodium Percentage (ESP) is 6% or greater.
p.13
Factors Affecting Weathering
How do joint patterns affect weathering?
Well jointed rocks are more subjected to mechanical disintegration.
p.70
Soil Composition and Formation
What are podzol and laterites collectively described as?
Pedalfer group (iron accumulating group).
p.11
Factors Affecting Weathering
What role do flora and microfauna play in weathering?
They affect different processes of weathering.
p.126
Soil Water and Its Role in Plant Growth
What is hydraulic head (h) expressed in?
Units of length (meters).
p.104
Soil Composition and Formation
Which cations are compared to sodium in sodic soils?
Calcium, magnesium, and potassium.
p.55
Soil Composition and Formation
What happens to humus upon complete decomposition?
It forms several organic acids that serve as solvents for soil materials.
p.24
Types of Weathering: Physical, Chemical, and Biological
What is necessary for the oxidation of minerals in rocks?
Oxygen must be dissolved in water.
p.126
Soil Water and Its Role in Plant Growth
What does the hydraulic head at location z represent?
The energy state of groundwater at that location.
p.78
Soil Composition and Formation
How does a ped differ from a fragment?
A fragment refers to a broken ped.
p.68
Soil Composition and Formation
What is Gleization?
A soil formation process occurring in wet and cold Tundra regions.
p.101
Soil Composition and Formation
Which types of ions contribute to soil electrical conductivity?
Cations (Ca2+, Mg2+, K+, Na+, NH4+) and anions (SO4 2-, Cl-, NO3-, HCO3-).
p.59
Soil Atmosphere and Its Importance
What role does wind play in the soil atmosphere?
Wind helps the soil in sucking the air in.
p.25
Types of Weathering: Physical, Chemical, and Biological
What is produced from the further oxidation of ferrous oxides?
Ferric oxides (Fe2O3) or ferric hydroxides (Fe(OH)3).
p.66
Soil Composition and Formation
What is the role of the E horizon in a soil profile?
It is a leached layer where minerals and nutrients are removed.
p.101
Soil Composition and Formation
How is electrical conductivity (EC) used in agriculture?
As a measure of soil salinity.
p.99
Soil Composition and Formation
What is a Melanic horizon?
A thick black horizon (>4.0% organic carbon) at or near the soil surface.
p.60
Soil Water and Its Role in Plant Growth
What does soil water maintain in the soil?
Soil texture, arrangement, and compactness of soil particles.
p.27
Types of Weathering: Physical, Chemical, and Biological
What effect does the increase in volume of hydrated rocks have?
It causes stress and strain in the minerals, leading to physical disintegration of rocks.
p.34
Factors Affecting Weathering
How does deforestation affect slope stability?
It reduces mechanical reinforcement and cohesion of unconsolidated geomaterials.
p.128
Soil Water and Its Role in Plant Growth
What does the water table represent?
The boundary between the saturated zone and the unsaturated zone.
p.38
Mass Movement and Its Classification
What does the study of mass movement involve?
Analysis of meaning, classification, causes, and geomorphic significance of mass movement.
p.34
Mass Movement and Its Classification
What is a consequence of increased slope instability due to anthropogenic weathering?
It causes slope failures and mass movement of materials.
p.70
Soil Composition and Formation
What is laterite?
A residue formed from the precipitation of aluminium and iron hydroxides during laterisation.
p.95
Soil Composition and Formation
What does the term 'colloid' derive from?
The Greek words 'kolla' meaning glue and 'eoids' meaning appearance.
p.24
Types of Weathering: Physical, Chemical, and Biological
What happens when water is mixed with oxygen in the context of chemical weathering?
It reacts with the minerals of the rocks to form hydroxide.
p.70
Soil Composition and Formation
Do laterites show well differentiated horizons?
No, laterites usually do not show well differentiated horizons.
p.49
Soil Composition and Formation
What are the mineral constituents of soil derived from?
Parental rocks or regolith.
p.14
Factors Affecting Weathering
What happens to rocks in regions of steep hillslope?
They are easily disintegrated due to mechanical weathering.
p.117
Clay Minerals and Their Characteristics
What is the general formula for Illite minerals?
(K 1–1.5 Al 4 [Si 7–6.5 Al 11–1.5 O 20 ](OH) 4).
p.80
Soil Composition and Formation
What is the average density of soil?
2.65 grams per cubic centimeter.
p.24
Types of Weathering: Physical, Chemical, and Biological
How does oxidation weaken rocks?
By producing oxides that cause the rocks to disintegrate.
p.99
Soil Composition and Formation
What defines an Ochric horizon?
Light colored, low organic content, may be hard and massive when dry.
p.108
Soil Composition and Formation
What is unique about hydrogen in the context of cation exchange?
It is held by colloids most tenaciously and is the most powerful replacer of cations.
p.23
Types of Weathering: Physical, Chemical, and Biological
What does solution refer to in the context of chemical weathering?
The dissolution of soluble particles and minerals from rocks with the help of water.
p.31
Biological Weathering
How do organisms help in extending weathering at greater depths?
By moving organic matter downward into the soil profiles.
p.25
Types of Weathering: Physical, Chemical, and Biological
What happens when water mixed with atmospheric oxygen contacts iron-bearing rocks?
The iron oxidizes to form ferrous oxides (FeO).
p.26
Types of Weathering: Physical, Chemical, and Biological
What is carbonation in the context of chemical weathering?
The reaction of carbonate or bicarbonate ions with minerals.
p.33
Types of Weathering: Physical, Chemical, and Biological
What activities contribute to anthropogenic weathering?
Mining, blasting for construction, and quarrying.
p.19
Types of Weathering: Physical, Chemical, and Biological
What role do strong winds play in exfoliation weathering?
They remove (peel off) the loosened shells of rocks.
p.78
Soil Composition and Formation
What aspects of soil aggregates does soil structure reveal?
Colour, texture, and chemical composition.
p.128
Soil Water and Its Role in Plant Growth
What is the hydraulic head found under a semi-permeable layer called?
Piezometric level or piezometric head.
p.89
Soil Composition and Formation
How do living microorganisms contribute to soil organic matter?
They add organic matter in the form of metabolic wastes.
p.132
Soil Water and Its Role in Plant Growth
Why is condensational water important in arid regions?
Because precipitation is scanty and there is rapid evaporation.
p.97
Soil Composition and Formation
What is a colloidal suspension of liquid in gas?
Examples include clouds and fogs in the atmosphere.
p.50
Soil Composition and Formation
What is humus?
A dark colored, jelly-like amorphous substance composed of residual organic matters not readily decomposed by soil microorganisms.
p.16
Types of Weathering: Physical, Chemical, and Biological
What are some examples of physical weathering agents?
Moisture and water, frost, insolation (temperature), and wind.
p.130
Soil Water and Its Role in Plant Growth
What forms of water are included in meteoric water?
Water in lakes, rivers, and ice melts.
p.45
Mass Movement and Its Classification
What are the subcategories of soil flow?
Debris flow and earth flow.
p.96
Soil Composition and Formation
What are the two phases of a colloidal system?
Dispersion phase (medium) and dispersed phase (suspended particles).
p.28
Types of Weathering: Physical, Chemical, and Biological
What is the most common type of chemical weathering process?
Hydrolysis of potassium feldspar (orthoclase) with carbonic acid in water.
p.11
Types of Weathering: Physical, Chemical, and Biological
Where is chemical decomposition more prevalent?
In hot and humid and temperate humid regions.
p.114
Clay Minerals and Their Characteristics
What type of clay mineral is Kaolinite?
A 1:1 type, with one tetrahedral sheet and one octahedral sheet.
p.22
Types of Weathering: Physical, Chemical, and Biological
What is chemical weathering?
The process by which rocks break down due to chemical reactions, altering their mineral composition.
p.52
Soil Composition and Formation
Is humus soluble in water?
No, humus is not soluble in water.
p.35
Types of Weathering: Physical, Chemical, and Biological
What is biochemical weathering?
Decomposition and disintegration of rocks due to organic materials from flora and fauna.
p.75
Soil Texture and Stability
Can soil texture be altered in a given sample area?
No, it is a basic property that cannot be altered.
p.101
Soil Composition and Formation
What does soil electrical conductivity (EC) measure?
The ability of soil water to carry electrical current.
p.48
Soil Composition and Formation
What is the primary role of soil in the environment?
Essential for the existence of life on Earth.
p.80
Soil Composition and Formation
What factors cause variation in soil density?
The degree of weathering.
p.65
Soil Composition and Formation
What is a soil profile?
A vertical section of soil that shows different layers or horizons.
p.13
Factors Affecting Weathering
What happens to rocks with vertical strata during weathering?
They are easily loosened and broken down due to temperature changes, frost action, water, and wind actions.
p.84
Soil Composition and Formation
What factors affect the size of pore space in soil?
Soil texture, soil structure, and vegetation.
p.15
Factors Affecting Weathering
What conditions contribute to effective leaching and rock solution in humid tropics?
Abundance of moisture and high temperature.
p.117
Clay Minerals and Their Characteristics
Which cations commonly occupy the interlayer sites in Illite minerals?
Monovalent cations, commonly K+.
p.52
Soil Composition and Formation
Where is humus quantity greater in the soil?
In the top layer compared to deep layers.
p.122
Soil Water and Its Role in Plant Growth
What types of sciences does hydrogeology involve?
Physical, biological, and mathematical sciences.
p.100
Soil Composition and Formation
What defines Sombric horizons?
Draining horizon formed due to illuviation of humus, not aluminum or sodium.
p.52
Soil Composition and Formation
How does the amount of humus in arid soils compare to humid soils?
It is less in arid soils and very high in humid soils.
p.99
Soil Composition and Formation
What defines a Folistic horizon?
Organic soil materials that remain saturated for less than one month.
p.20
Types of Folds in Geology
In which types of rocks is sheeting commonly developed?
Massive rocks such as granites, quartzites, and thickly bedded sandstones.
p.11
Factors Affecting Weathering
How do climatic conditions influence weathering?
They affect different processes of weathering to a greater extent.
p.89
Soil Composition and Formation
What have chemists been studying in relation to soil science?
The composition of humus.
p.60
Soil Water and Its Role in Plant Growth
How does water affect plant growth?
It influences growth and other physiological activities.
p.12
Factors Affecting Weathering
What is one major factor affecting weathering?
Climate, including temperature and precipitation.
p.125
Soil Composition and Formation
What are bedrocks?
Rocks that have not been weathered and eroded.
p.117
Clay Minerals and Their Characteristics
What type of layer structure do Illite minerals have?
A 2:1 layer structure with an interlayer structure.
p.80
Soil Composition and Formation
How is soil density expressed?
In grams per cubic centimeter.
p.125
Soil Water and Its Role in Plant Growth
What is the main source of groundwater?
Rainwater and meltwater that infiltrates downward.
p.24
Types of Weathering: Physical, Chemical, and Biological
What is produced when atmospheric oxygen reacts with rocks?
Several types of oxides, with iron oxide being the most important.
p.96
Soil Composition and Formation
What is the dispersion phase in a colloidal system?
The medium in which the particles are suspended.
p.100
Soil Composition and Formation
What is the characteristic of Spodic horizons?
Accumulation of organic matter, Fe, and Al oxides.
p.125
Soil Water and Its Role in Plant Growth
How does water become groundwater?
By infiltrating downward through the pore spaces of surficial material.
p.88
Soil Composition and Formation
What happens to dead plants and animals in soil?
They are subjected to decomposition.
p.73
Soil Texture and Stability
What does porosity in soil indicate?
The amount of empty space between soil particles.
p.21
Types of Weathering: Physical, Chemical, and Biological
How does fire contribute to insolation weathering?
Brushfire causes thermal expansion and contraction of rocks, leading to exfoliation and the production of spalls and flakes.
p.106
Soil Composition and Formation
What is the role of cation exchange in soil health?
It helps in nutrient availability and soil fertility.
p.66
Soil Composition and Formation
What is the significance of the B horizon in a soil profile?
It is the subsoil layer where minerals leached from above accumulate.
p.115
Clay Minerals and Their Characteristics
What type of clay mineral is Chlorite?
A 2:1 type of clay mineral containing magnesium and iron ions.
p.23
Types of Weathering: Physical, Chemical, and Biological
Which types of rocks are most susceptible to the solution process?
Limestones and dolomites.
p.58
Soil Atmosphere and Its Importance
What happens to soil productivity when soluble nutrients accumulate?
It makes the soil more productive.
p.35
Types of Weathering: Physical, Chemical, and Biological
How do organic materials contribute to the weathering of rocks?
They facilitate decomposition through various biochemical processes.
p.65
Soil Composition and Formation
What is the O horizon in a soil profile?
The top layer composed mainly of organic matter such as decomposed leaves.
p.83
Soil Composition and Formation
Why is bulk density useful in soil studies?
It helps understand and estimate the physical behavior of the soil.
p.91
Types of Folds in Geology
List the pyrimidines mentioned.
Cytosine, Thymine, Uracil.
p.91
Types of Folds in Geology
What are aromatic molecules?
Compounds that contain a ring structure with delocalized electrons.
p.96
Soil Composition and Formation
What state do colloidal substances exist in when suspended in a solvent?
In a suspension state, floating but not settling at the bottom.
p.113
Clay Minerals and Their Characteristics
Name a few types of clay minerals.
Kaolinite, smectite, illite, chlorite, and vermiculite.
p.132
Soil Water and Its Role in Plant Growth
What causes the pressure difference that allows atmospheric water vapor to penetrate rocks?
The warmer air over land compared to the cooler air trapped in the soil.
p.30
Types of Weathering: Physical, Chemical, and Biological
What is faunal weathering?
Weathering caused by animals.
p.126
Soil Water and Its Role in Plant Growth
What are some physical characteristics of groundwater?
Velocity, density, temperature, and energy state.
p.89
Soil Composition and Formation
What specific elements are found in the organic component of soil?
Carbon, hydrogen, oxygen, phosphorus, nitrogen, sulfur, and small amounts of other elements.
p.88
Soil Composition and Formation
How much organic matter is typically found in sandy soil of arid zones?
Very poor quantity, one percent or less.
p.66
Soil Composition and Formation
What are the main layers of a soil profile?
O horizon, A horizon, E horizon, B horizon, and C horizon.
p.126
Soil Water and Its Role in Plant Growth
What determines groundwater flow?
The energy state of the groundwater.
p.19
Types of Weathering: Physical, Chemical, and Biological
What causes exfoliation weathering?
Combined actions of heat and wind.
p.37
Types of Weathering: Physical, Chemical, and Biological
What is biological weathering?
The process of rock breakdown caused by living organisms.
p.107
Soil Composition and Formation
What role do plant roots play in cation exchange?
They release cations that can exchange with those on the surface of soil colloids.
p.104
Soil Composition and Formation
How is the Exchangeable Sodium Percentage (ESP) calculated?
ESP = Exchangeable {(Na)/(Ca + Mg + K + Na)} x 100.
p.7
Exogenetic Forces and Weathering Processes
What does denudation include?
Both weathering and erosion.
p.114
Clay Minerals and Their Characteristics
What is the chemical composition of Kaolinite?
Silica, alumina, and water.
p.59
Soil Atmosphere and Its Importance
What are the important factors that change the soil atmosphere?
Temperature, atmospheric pressure, wind, and rainfall.
p.28
Types of Weathering: Physical, Chemical, and Biological
What role does carbonic acid play in the hydrolysis of potassium feldspar?
It reacts with potassium feldspar to facilitate the weathering process.
p.107
Soil Composition and Formation
What are the three scenarios in which cation exchange can occur?
1) Between cations in soil solutions and those on soil colloids, 2) Between cations released by plant roots and those on soil colloids, 3) Between cations on the surfaces of clay crystals or organic colloids.
p.33
Types of Weathering: Physical, Chemical, and Biological
How does modern technology impact weathering?
It has made humans the most powerful weathering and erosion agents.
p.65
Soil Composition and Formation
What are the main layers of a soil profile?
O horizon, A horizon, E horizon, B horizon, and C horizon.
p.66
Soil Composition and Formation
What does the C horizon consist of in a soil profile?
It consists of weathered rock and parent material.
p.49
Soil Composition and Formation
How does nitrogen enter the soil?
From the atmosphere in the form of nitrogen salts.
p.21
Types of Weathering: Physical, Chemical, and Biological
What is salt weathering?
Disaggregation of rocks due to the growth of salt crystals from solution, typically occurring in hot arid areas.
p.22
Types of Weathering: Physical, Chemical, and Biological
What role do biological organisms play in chemical weathering?
They can produce organic acids that enhance the weathering process.
p.59
Soil Atmosphere and Its Importance
How does rainfall affect the soil atmosphere?
Rainwater displaces the soil air.
p.75
Soil Texture and Stability
What is the significance of soil texture in agriculture?
It affects water retention, nutrient availability, and soil stability.
p.53
Soil Composition and Formation
What happens to the duff layer during decomposition?
It decomposes completely into organic substances.
p.95
Soil Composition and Formation
What is a true solution?
A solution where crystal particles cannot be seen with a microscope.
p.31
Biological Weathering
What is faunal weathering?
The process where burrowing animals and organisms help in the gradual breakdown of rocks.
p.72
Soil Composition and Formation
What begins to occur as a result of anaerobic conditions in hydromorphic soils?
Chemical reduction processes.
p.66
Soil Composition and Formation
What is a soil profile?
A vertical section of soil that shows different layers or horizons.
p.84
Soil Composition and Formation
What is porosity?
The space between primary particles and between or within aggregates filled with air and water.
p.51
Soil Composition and Formation
What does tree litter contain besides organic matter?
Inorganic substances such as lime, potash, Mn, Mg, silica, Cu, Al, Ca, Na, K, etc.
p.130
Soil Water and Its Role in Plant Growth
How does meteoric water originate?
It originates in the atmosphere by evaporation.
p.132
Soil Water and Its Role in Plant Growth
What can the process of condensation lead to in arid and desert regions?
The accumulation of a certain amount of water in rocks.
p.99
Soil Composition and Formation
How does an Umbric horizon differ from a Mollic horizon?
It is the same as Mollic except it has low base saturation.
p.55
Soil Composition and Formation
How does humus benefit plants and microorganisms?
It provides nutrients to them.
p.13
Factors Affecting Weathering
Which type of rocks are more easily affected by chemical weathering?
Carbonate rocks, such as calcium carbonate and magnesium carbonate.
p.33
Types of Weathering: Physical, Chemical, and Biological
What is anthropogenic weathering?
Weathering accelerated or decelerated by human activities.
p.130
Soil Water and Its Role in Plant Growth
What happens to infiltrating water after it seeps into the ground?
It continues its downward journey to the zone of saturation.
p.98
Soil Composition and Formation
What distinguishes a reversible gel from an irreversible gel?
Reversible gels can return to a sol state, while irreversible gels cannot.
p.37
Types of Weathering: Physical, Chemical, and Biological
How do plant roots contribute to biological weathering?
By growing into cracks in rocks and exerting pressure.
p.99
Soil Composition and Formation
What is a Histic horizon characterized by?
Very high in organic content, wet during some part of the year.
p.7
Exogenetic Forces and Weathering Processes
What characterizes erosion in the context of denudation?
It is a dynamic process that includes the removal of materials and their transportation to different destinations.
p.122
Soil Water and Its Role in Plant Growth
How is hydrogeology related to hydrology?
It is a subdivision of hydrology that deals with water beneath the Earth's surface.
p.62
Soil Water and Its Role in Plant Growth
How does water requirement vary among plants?
Some plants absorb large quantities, while others require very small amounts for normal growth.
p.101
Soil Composition and Formation
What determines the electrical conductivity (EC) of soils?
The concentration of ions in the soil water.
p.62
Soil Water and Its Role in Plant Growth
What happens to the majority of water absorbed by plants?
It is transpired by the plants.
p.58
Soil Atmosphere and Its Importance
How can undesirable processes in soil affect plants?
They may be injurious to plants.
p.26
Types of Weathering: Physical, Chemical, and Biological
What type of rocks does carbonation primarily affect?
Carbonate rocks, such as limestones.
p.15
Types of Weathering: Physical, Chemical, and Biological
What type of weathering is more effective in tropical and semi-arid regions?
Mechanical disintegration of rocks.
p.100
Soil Composition and Formation
What is a Petrocalcic horizon?
An indurated calcic horizon with a hardness of 3 or more on the Mohs scale.
p.68
Soil Composition and Formation
What is the iron content like in the surface layer formed by Gleization?
Reduced content of iron compounds.
p.36
Types of Weathering: Physical, Chemical, and Biological
What role do humic acids play in biological weathering?
They activate chelation and help in the decomposition of silicate minerals.
p.51
Soil Composition and Formation
What important compounds are found in humus?
Carbohydrates, phosphoric acid, organic acids, fats, resins, urea, etc.
p.41
Mass Movement and Its Classification
What is solifluction?
A type of slow mass movement involving the flow of water-saturated soil.
p.14
Mass Movement and Its Classification
How does ground slope affect rocks?
It controls mechanical disintegration of rocks and mass movement of weathered products down the slope.
p.30
Types of Weathering: Physical, Chemical, and Biological
What is floral weathering?
Weathering caused by plants.
p.108
Soil Composition and Formation
Are all cations adsorbed with equal ease?
No, some are easily adsorbed while others are replaced with difficulty.
p.84
Soil Composition and Formation
What are macropores?
Larger pores in soil, termed as non-capillary pores, greater than 0.05 mm.
p.45
Mass Movement and Its Classification
What are the three types of lateral flow?
Rock spread, debris spread, and earth spread.
p.66
Soil Composition and Formation
What is the O horizon in a soil profile?
The top layer rich in organic matter, such as decomposed leaves.
p.49
Soil Composition and Formation
What is the size range of soil particles?
From clay (0.0002 mm or less in diameter) to large pebbles and gravels.
p.19
Types of Weathering: Physical, Chemical, and Biological
In which regions is exfoliation weathering more common?
Hot arid and semi-arid regions and monsoon lands.
p.83
Soil Composition and Formation
How does organic matter affect soil density?
It decreases soil density.
p.84
Soil Atmosphere and Its Importance
How is soil air related to soil water?
Soil air is inversely proportional to soil water; water displaces air in the soil.
p.114
Clay Minerals and Their Characteristics
What industries commonly use Kaolinite?
Paper, ceramics, and cosmetics industries.
p.122
Soil Water and Its Role in Plant Growth
What does hydrogeology focus on?
The occurrence and movement of subterranean water.
p.35
Types of Weathering: Physical, Chemical, and Biological
What types of organic acids are produced during biochemical weathering?
Humic acids, bacterial acids, and microfaunal acids.
p.22
Types of Weathering: Physical, Chemical, and Biological
What is hydrolysis in the context of chemical weathering?
A chemical reaction between water and minerals that leads to the formation of new minerals and soluble ions.
p.78
Soil Composition and Formation
What is the difference between a ped and a concretion?
A concretion is formed by the precipitation of salts dissolved in percolating water.
p.58
Soil Atmosphere and Its Importance
What undesirable processes can occur in oxygen-deficient soil?
Evolution of nitrogen, methane, accumulation of sulphides, ferrous, manganous ions, and organic inhibitors.
p.33
Types of Weathering: Physical, Chemical, and Biological
How does the rate of disintegration from human activities compare to natural weathering?
Human activities can cause disintegration at rates that would take natural processes thousands to millions of years.
p.23
Types of Weathering: Physical, Chemical, and Biological
How does rainwater become an active solvent?
When it mixes with atmospheric CO2.
p.55
Soil Composition and Formation
How does humus influence soil aeration and percolation?
It makes the soil porous, thus increasing aeration and percolation.
p.26
Types of Weathering: Physical, Chemical, and Biological
What is produced when carbonic acid reacts with limestone?
Calcium bicarbonate (Ca(HCO3)2).
p.115
Clay Minerals and Their Characteristics
What are some uses of Vermiculite?
As a soil amendment, filler in construction materials, and in horticulture.
p.129
Soil Composition and Formation
Where are connate waters found?
In the pores of sedimentary rocks at their time of deposition.
p.32
Types of Weathering: Physical, Chemical, and Biological
Does floral weathering occur independently?
No, it helps the physical and chemical processes of weathering.
p.97
Soil Composition and Formation
Which type of colloids are the most common?
Those that remain suspended in a liquid medium.
p.16
Types of Weathering: Physical, Chemical, and Biological
Which agents are considered chemical weathering agents?
Oxygen, carbon dioxide, and hydrogen.
p.32
Types of Weathering: Physical, Chemical, and Biological
How do larger plants affect weathering?
By widening cracks through root penetration and root pressure.
p.12
Factors Affecting Weathering
How does rock type influence weathering?
Different rock types have varying resistance to weathering processes.
p.88
Soil Composition and Formation
What is the organic matter content in peaty soil?
It may be as high as 90%.
p.16
Types of Weathering: Physical, Chemical, and Biological
What role do biological weathering agents play?
They include vegetation and animals, mainly micro-organisms.
p.126
Soil Water and Its Role in Plant Growth
How is the energy state of groundwater commonly expressed?
As hydraulic head (h) per unit weight.
p.21
Types of Weathering: Physical, Chemical, and Biological
What is dirt cracking?
Fracturing and splitting of boulders containing 'dirt' due to thermal expansion and contraction.
p.22
Types of Weathering: Physical, Chemical, and Biological
What are common agents of chemical weathering?
Water, acids, and oxygen.
p.35
Types of Weathering: Physical, Chemical, and Biological
What processes are involved in biochemical weathering?
Cation root exchange, chelation, solution by root exudates, and production of organic acids.
p.75
Soil Texture and Stability
What are soil separates?
Particles defined by their size, including sand, silt, and clay.
p.63
Soil Water and Its Role in Plant Growth
What occurs in plants at the permanent wilting stage?
Permanent wilting occurs.
p.108
Soil Composition and Formation
How do the replacing capacities of cations compare?
H+ > Ca2+ > Mg2+ > K+ > Na+.
p.80
Soil Composition and Formation
What are the two generally accepted forms of soil density?
Particle density (true density) and bulk density.
p.12
Factors Affecting Weathering
What is the impact of human activity on weathering?
Human activities can accelerate weathering through pollution and land use changes.
p.99
Soil Composition and Formation
What is unique about an Anthropic horizon?
It is a man-modified Mollic-like horizon, high in available phosphorus.
p.69
Soil Composition and Formation
What type of soil is formed as a result of podzolisation?
Podzol, which is acidic and unproductive.
p.25
Types of Weathering: Physical, Chemical, and Biological
What effect does the rusting of rocks have on them?
It weakens them and ultimately leads to disintegration.
p.115
Clay Minerals and Their Characteristics
What is a unique characteristic of Vermiculite?
It can expand when heated.
p.68
Soil Composition and Formation
What types of changes occur in the Gleization process?
Chemical, physical, and biological changes.
p.129
Soil Composition and Formation
What do connate waters contain besides water?
Many mineral components in the form of ions in solution.
p.63
Soil Water and Its Role in Plant Growth
What happens when the soil water content becomes too low?
It cannot supply water to growing plants rapidly enough, leading to permanent wilting.
p.32
Types of Weathering: Physical, Chemical, and Biological
What effect does dense vegetation cover have on the ground surface?
It generates a distinct microclimate.
p.131
Soil Composition and Formation
What is the movement of juvenile water characterized by?
Moving from high temperature and pressure to low temperature and pressure.
p.107
Soil Composition and Formation
What types of colloids can participate in cation exchange?
Clay crystals, organic colloids, or a combination of both.
p.62
Soil Water and Its Role in Plant Growth
What is combined water?
Water of chemical compounds held by chemical forces of molecules, such as CuSO4.5H₂O.
p.58
Soil Atmosphere and Its Importance
What effect does oxygen deficiency in soil have on microbial activities?
It slows down and may eliminate microbial activities.
p.69
Soil Composition and Formation
What is podzolisation?
A process where acids produced during decomposition make the soil acidic, leading to the formation of podzol.
p.52
Soil Composition and Formation
What factors affect the percentage of humus in soil?
Climatic and biological factors.
p.114
Clay Minerals and Their Characteristics
What type of clay mineral is Smectite?
A 2:1 type, with two tetrahedral sheets and one octahedral sheet.
p.114
Clay Minerals and Their Characteristics
What is a key characteristic of Smectite?
It has a high cation exchange capacity and can expand when hydrated.
p.65
Soil Composition and Formation
What characterizes the A horizon in a soil profile?
It is the topsoil layer rich in minerals and organic material, crucial for plant growth.
p.59
Soil Atmosphere and Its Importance
What is the impact of considerable changes in the soil atmosphere?
It affects the size and function of microflora and other biological populations.
p.69
Soil Composition and Formation
What happens to humus and minerals during podzolisation?
They move downward with percolating water and accumulate in lower horizons.
p.99
Soil Composition and Formation
What characterizes a Grossarenic horizon?
A sandy horizon, 100 cm or more thick over an Argillic horizon.
p.129
Soil Composition and Formation
Why is connate water typically saline?
Because it is formed from ocean sediments.
p.108
Soil Composition and Formation
Which type of cations are more effective in soil exchange reactions?
Divalent cations are more effective than monovalent ones.
p.84
Soil Composition and Formation
What are micropores?
Smaller pores in soil, known as capillary pores, less than 0.05 mm.
p.14
Mass Movement and Its Classification
What forms of mass movement occur on steep slopes?
Rockfall, debris fall, slide, faults, and creep.
p.63
Soil Water and Its Role in Plant Growth
What is the term for the moisture percentage in soil at the permanent wilting stage?
Wilting coefficient or permanent wilting percentage.
p.53
Soil Composition and Formation
What characterizes the litter layer in humus degradation?
It is covered with dead organic parts showing a low degree of decomposition.
p.12
Factors Affecting Weathering
How does time affect weathering processes?
Longer exposure to weathering agents increases the degree of weathering.
p.101
Soil Composition and Formation
What is the principal process through which electrical conductivity occurs in soil?
An electrolytic process through water-filled pores.
p.59
Soil Atmosphere and Its Importance
How do temperature and atmospheric pressure affect soil air?
They cause expansion and contraction of the soil air.
p.55
Soil Composition and Formation
How does humus affect mineral availability in soil?
It increases the availability of minerals in dissolved state to plants.
p.13
Factors Affecting Weathering
How do horizontal beds of rocks compare to vertical strata in terms of weathering?
Horizontal beds are more compact and less affected by disintegration and decomposition mechanisms.
p.48
Soil Composition and Formation
What are the four major components of soil?
Minerals (45%), water (25%), air (25%), and organic matter (5%).
p.68
Soil Composition and Formation
In which regions does Gleization occur?
Wet and cold Tundra regions.
p.99
Soil Composition and Formation
What is a Plaggen horizon?
A man-made sod-like horizon created by years of manuring.
p.84
Soil Water and Its Role in Plant Growth
How does the presence of micropores affect air movement and water percolation?
Air movement and water percolation are low in the case of micropores.
p.62
Soil Water and Its Role in Plant Growth
What is the soil moisture stress?
The diffusion pressure deficit that affects the availability of soil water to plants.
p.55
Soil Composition and Formation
How does the presence of humus affect plant absorption rates?
It increases the rate of absorption in plants.
p.26
Types of Weathering: Physical, Chemical, and Biological
What effect does dissolved carbon dioxide have on groundwater?
It makes groundwater a more active solvent.
p.129
Soil Composition and Formation
What is connate water?
Water trapped in rock strata at the time of rock formation.
p.12
Factors Affecting Weathering
What role does vegetation play in weathering?
Vegetation can protect soil and rocks from erosion and contribute to chemical weathering.
p.58
Soil Atmosphere and Its Importance
Why is the presence of oxygen in the soil important?
It helps in the breakdown of insoluble rocky mass into soluble minerals and in humification.
p.14
Factors Affecting Weathering
What is the effect of instantaneous removal of weathering products?
It allows continuous exposure of rocks to atmospheric conditions for further weathering.
p.51
Soil Composition and Formation
What is the carbon and nitrogen content in humus?
Humus has much carbon content and less nitrogen.
p.49
Soil Composition and Formation
Name some important elements found in soil.
Oxygen, Silicon (Si), Iron (Fe), Aluminum (Al), Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Carbon (C), Hydrogen (H).
p.21
Types of Weathering: Physical, Chemical, and Biological
What is slaking weathering?
Disintegration of rocks due to alternate wetting and drying, causing expansion and contraction of rock shells.
p.37
Types of Weathering: Physical, Chemical, and Biological
What role do microorganisms play in biological weathering?
They can produce acids that dissolve minerals in rocks.
p.83
Soil Composition and Formation
What information does bulk density provide about soil?
It provides information about the porosity of the soil.
p.23
Factors Affecting Weathering
What factors influence the solution process in rocks?
Temperature, CO2 content of water, and pH of the solution.
p.55
Soil Composition and Formation
What is a key physical property of humus that aids water retention?
It is porous, giving it a high capacity for retaining water.
p.114
Clay Minerals and Their Characteristics
In which applications is Smectite commonly used?
Drilling muds, as a binder in foundry sands, and in the construction industry.
p.69
Soil Composition and Formation
What minerals are involved in the podzolisation process?
Dissolved Si, Fe, and Al salts.
p.65
Soil Composition and Formation
What is the E horizon in a soil profile?
A leached layer where minerals and nutrients are washed away, often lighter in color.
p.25
Types of Weathering: Physical, Chemical, and Biological
What are various iron silicates involved in chemical weathering?
They include minerals that contain iron in silicate form.
p.10
Types of Weathering: Physical, Chemical, and Biological
What does P. Reiche define weathering as?
The response of minerals in equilibrium within the lithosphere to conditions at or near its contact with the atmosphere, hydrosphere, and biosphere.
p.84
Soil Water and Its Role in Plant Growth
How does the presence of macropores affect air movement and water percolation?
Air movement and water percolation are high in the presence of macropores.
p.15
Types of Weathering: Physical, Chemical, and Biological
How does mechanical weathering compare in humid tropics versus tropical and semi-arid regions?
Mechanical weathering is less effective in humid tropics but more dominant in tropical and semi-arid regions.
p.19
Types of Weathering: Physical, Chemical, and Biological
What phenomenon causes flaking in rocks during exfoliation?
Differential heating of outer and lower shells of a rock mass.
p.100
Soil Composition and Formation
What is a Kandic horizon characterized by?
Low activity clays with or without clay skins.
p.62
Soil Water and Its Role in Plant Growth
What does soil moisture stress refer to?
The total of all the forces that plants must overcome to take up water from the soil.
p.26
Types of Weathering: Physical, Chemical, and Biological
How does rainwater contribute to the process of carbonation?
It percolates through soil horizons, dissolving carbon dioxide.
p.129
Soil Composition and Formation
What is the result of increased pore fluid pressure in rocks?
It can lead to overpressure.
p.33
Types of Weathering: Physical, Chemical, and Biological
What role does mining play in weathering?
It accelerates the disintegration of geological materials.
p.23
Types of Weathering: Physical, Chemical, and Biological
What is the solubility of common salts compared to carbonate rocks?
Common salts are most soluble, while carbonate rocks have moderate solubility.
p.91
Types of Folds in Geology
What are uronic acids?
Carbohydrates that contain a carboxylic acid group.
p.57
Soil Atmosphere and Its Importance
What are the three main gases in the soil atmosphere?
Oxygen, carbon dioxide, and nitrogen.
p.78
Soil Composition and Formation
What factors influence soil structure?
Air, moisture, organic matter, micro-organisms, and root growth.
p.55
Soil Composition and Formation
What structural role does humus play in soil?
It acts as weak cement, binding sand particles.
p.23
Types of Weathering: Physical, Chemical, and Biological
What happens when rainwater comes in contact with carbonate rocks?
It dissolves the rocks through a set of chemical reactions.
p.65
Soil Composition and Formation
What is the C horizon in a soil profile?
The layer consisting of weathered rock and parent material from which soil develops.
p.57
Soil Atmosphere and Its Importance
What happens to carbon dioxide in the soil during respiration?
CO₂ is given out and accumulates in soil spaces.
p.52
Soil Composition and Formation
What happens to humus in dark humid areas with thick vegetation?
Humus may be found in degradation.
p.129
Soil Composition and Formation
What happens to connate liquids as rocks undergo lithification?
They are expelled from the rocks.
p.115
Clay Minerals and Their Characteristics
What is the cation exchange capacity of Vermiculite?
It has a high cation exchange capacity.
p.65
Soil Composition and Formation
What does the B horizon represent in a soil profile?
The subsoil layer that accumulates minerals leached from above layers.
p.69
Factors Affecting Weathering
Why is the rate of decomposition slow in areas undergoing podzolisation?
Due to cold and moist climate conditions.
p.57
Soil Atmosphere and Its Importance
How does the amount of CO₂ change with soil depth?
It increases with depth due to decomposition of organic matter and abundance of plant roots.
p.100
Soil Composition and Formation
What defines a Petrogypsic horizon?
A strongly cemented gypsic horizon whose dry fragments do not slake in water.
p.57
Soil Atmosphere and Its Importance
How does the carbon dioxide level in cultivated land compare to atmospheric levels?
The percentage of CO₂ is much higher in cultivated land.
p.69
Soil Composition and Formation
What conditions enhance the effectiveness of podzolisation?
Sandy base-poor parent materials under intense leaching and thick vegetational cover.
p.100
Soil Composition and Formation
What is the characteristic of Placic horizons?
A thin, slowly permeable horizon that is dark reddish-brown to black in color, containing Fe or Mn.
p.129
Soil Composition and Formation
What can cause pore fluid pressure to build up in rocks?
If the escape route for connate fluids is blocked.
p.57
Soil Atmosphere and Its Importance
Why is the oxygen content in cultivated soil poorer than in atmospheric air?
Because oxygen is absorbed by plant roots and soil microorganisms.
