Rocks, Weathering, Soil & Energy Resources – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering key terms from rocks and weathering through soil science and energy resources.

Biosphere

The life-supporting zone where lithosphere, atmosphere and hydrosphere overlap.

Lithosphere

The rigid outer layer of Earth, composed of the crust and uppermost mantle (rock sphere).

Hydrosphere

All water bodies on Earth, including oceans, rivers, lakes, groundwater and ice.

Atmosphere

The blanket of gases surrounding Earth.

Internal Forces

Endogenic processes such as mountain building, volcanism and earthquakes that construct landforms.

External Forces

Exogenic agents (water, wind, ice, waves) that wear, transport and remodel Earth’s surface.

Rock

Naturally formed solid mineral material composing the lithosphere.

Ore

A naturally occurring rock containing enough metal to be mined profitably (e.g., iron ore).

Igneous Rock

‘Primary’ rock formed by cooling and solidification of magma or lava.

Intrusive (Plutonic) Rock

Igneous rock that cools slowly beneath Earth’s surface, producing large crystals (e.g., granite).

Extrusive (Volcanic) Rock

Igneous rock that cools rapidly on or near the surface, usually fine-grained or glassy (e.g., basalt).

Sedimentary Rock

Rock formed by deposition, compaction and cementation of sediments; often layered and may contain fossils.

Mechanically Formed Sedimentary Rock

Sedimentary rock made of physically weathered fragments (clasts), e.g., sandstone.

Organically Formed Sedimentary Rock

Derived from accumulated plant or animal remains, e.g., limestone, coal.

Chemically Formed Sedimentary Rock

Created by direct chemical precipitation of minerals from solution, e.g., gypsum, rock salt.

Metamorphic Rock

Rock altered in mineralogy and texture by heat and/or pressure, e.g., granite → gneiss.

Weathering

In-situ breakdown of rocks by physical, chemical or biological processes.

Mechanical (Physical) Weathering

Disintegration of rock without chemical change; driven by temperature, frost, etc.

Chemical Weathering

Decomposition of rock through chemical reactions altering mineral composition.

Biological Weathering

Rock breakdown caused by plants, animals, microorganisms or human activities.

Exfoliation

Peeling of rock layers due to repeated heating and cooling (thermal expansion).

Frost Action

Mechanical weathering by freeze-thaw cycles widening rock cracks.

Oxidation

Chemical weathering where minerals react with oxygen, e.g., iron → rust.

Carbonation

Chemical reaction of carbonic acid in rainwater with carbonate rocks, dissolving limestone.

Hydration

Absorption of water into mineral structure causing expansion and weakness (feldspar → kaolin).

Solution (Weathering)

Dissolving of soluble minerals, removing them in water and weakening rock.

Gradation

Three-fold geomorphic process: degradation (erosion), transportation, aggradation (deposition).

Denudation

Lowering of Earth’s surface by weathering and erosion.

Soil

Mixture of minerals, organic matter, water, air and organisms forming the top layer of land.

Humus

Dark, nutrient-rich organic material of decomposed plant/animal matter in soil.

Soil Profile

Vertical section of soil showing successive layers (horizons) from surface to bedrock.

O-Horizon

Top organic layer of litter and humus.

A-Horizon (Topsoil)

Mineral soil mixed with humus; fertile and dark.

B-Horizon (Subsoil)

Layer where leached minerals accumulate; richer in clay and oxides.

C-Horizon (Regolith)

Partly weathered parent material above bedrock.

R-Horizon

Unweathered parent rock (bedrock) beneath the soil profile.

Soil Conservation

Practices preventing soil erosion and maintaining fertility.

Contour Ploughing

Tilling along land contours to reduce runoff and erosion.

Terraced Farming

Stepped fields on slopes that slow water flow and conserve soil.

Crop Rotation

Alternating crops to maintain soil nutrients and cover year-round.

Afforestation

Planting trees on non-forested land to prevent erosion and enhance cover.

Renewable Energy

Energy from inexhaustible sources like solar, wind, hydro, tidal, geothermal and biogas.

Non-Renewable Energy

Energy from exhaustible resources like coal, petroleum, natural gas and uranium.

Fossil Fuel

Energy resource derived from ancient organic matter; includes coal, oil, natural gas.

Solar Energy

Energy harnessed from sunlight using thermal collectors or photovoltaic cells.

Photovoltaic Cell

Device converting solar radiation directly into electricity.

Wind Energy

Electricity generated by wind turbines turning kinetic energy of air into power.

Hydroelectricity

Electric power produced by water falling through turbines in a dam.

Dam

Barrier built across a river to store water, control floods and generate power.

Multipurpose Project

River-valley scheme providing irrigation, power, flood control, etc. (e.g., Bhakra Nangal).

Damodar Valley Project

First major multipurpose project in India, controlling floods and generating power on River Damodar.

Bhakra Nangal Dam

High dam on River Sutlej supplying irrigation and hydel power to north-west India.

Sardar Sarovar Project

Large dam on Narmada River providing water and electricity to Gujarat and Madhya Pradesh.

Reduce, Reuse, Recycle

Three-R strategy for conserving mineral and energy resources.

Biogas

Methane-rich fuel from anaerobic decomposition of organic waste; used for cooking and lighting.

Contour Ploughing

Tillage along contour lines to minimise soil erosion (duplicate removed in list).

Selective Mining

Extraction of only high-grade ore, often leading to resource wastage; discouraged for conservation.

Karst Topography

Landscape of caves, sinkholes and grooves formed by dissolution of carbonate rocks.

Core (Earth)

Central part of Earth; outer core liquid, inner core solid, composed mainly of iron-nickel.

The _ is the life-supporting zone where lithosphere, atmosphere and hydrosphere overlap.

Biosphere

What is the rigid outer layer of Earth, composed of the crust and uppermost mantle?

Lithosphere

_ refers to all water bodies on Earth, including oceans, rivers, lakes, groundwater and ice.

Hydrosphere

What is the blanket of gases surrounding Earth?

Atmosphere

_ are endogenic processes such as mountain building, volcanism and earthquakes that construct landforms.

Internal Forces

Name the exogenic agents (water, wind, ice, waves) that wear, transport and remodel Earth’s surface.

External Forces

_ is naturally formed solid mineral material composing the lithosphere.

Rock

What is a naturally occurring rock containing enough metal to be mined profitably (e.g., iron ore)?

Ore

_ is ‘Primary’ rock formed by cooling and solidification of magma or lava.

Igneous Rock

What type of igneous rock cools slowly beneath Earth’s surface, producing large crystals (e.g., granite)?

Intrusive (Plutonic) Rock

_ is igneous rock that cools rapidly on or near the surface, usually fine-grained or glassy (e.g., basalt).

Extrusive (Volcanic) Rock

What type of rock is formed by deposition, compaction and cementation of sediments; often layered and may contain fossils?

Sedimentary Rock

_ is sedimentary rock made of physically weathered fragments (clasts), e.g., sandstone.

Mechanically Formed Sedimentary Rock

Limestone and coal are examples of what type of sedimentary rock, derived from accumulated plant or animal remains?

Organically Formed Sedimentary Rock

_ is created by direct chemical precipitation of minerals from solution, e.g., gypsum, rock salt.

Chemically Formed Sedimentary Rock

What type of rock is altered in mineralogy and texture by heat and/or pressure, e.g., granite → gneiss?

Metamorphic Rock

_ is the in-situ breakdown of rocks by physical, chemical or biological processes.

Weathering

What is the disintegration of rock without chemical change, driven by temperature, frost, etc.?

Mechanical (Physical) Weathering

_ is the decomposition of rock through chemical reactions altering mineral composition.

Chemical Weathering

What causes rock breakdown through rock breakdown caused by plants, animals, microorganisms or human activities?

Biological Weathering

_ is the peeling of rock layers due to repeated heating and cooling (thermal expansion).

Exfoliation

What mechanical weathering process involves freeze-thaw cycles widening rock cracks?

Frost Action

_ is chemical weathering where minerals react with oxygen, e.g., iron → rust.

Oxidation

What chemical process describes the reaction of carbonic acid in rainwater with carbonate rocks, dissolving limestone?

Carbonation

_ is the absorption of water into mineral structure causing expansion and weakness (feldspar → kaolin).

Hydration

What weathering process involves the dissolving of soluble minerals, removing them in water and weakening rock?

Solution (Weathering)

_ is a three-fold geomorphic process: degradation (erosion), transportation, aggradation (deposition).

Gradation

What is the term for the lowering of Earth’s surface by weathering and erosion?

Denudation

_ is a mixture of minerals, organic matter, water, air and organisms forming the top layer of land.

Soil

What is the dark, nutrient-rich organic material of decomposed plant/animal matter in soil?

Humus

A _ is a vertical section of soil showing successive layers (horizons) from surface to bedrock.

Soil Profile

Which horizon is the top organic layer of litter and humus?

O-Horizon

The _ is mineral soil mixed with humus; fertile and dark.

A-Horizon (Topsoil)

In which soil layer do leached minerals accumulate; richer in clay and oxides?

B-Horizon (Subsoil)

The _ is partly weathered parent material above bedrock.

C-Horizon (Regolith)

What is the unweathered parent rock (bedrock) beneath the soil profile called?

R-Horizon

_ refers to practices preventing soil erosion and maintaining fertility.

Soil Conservation

What agricultural practice involves tilling along land contours to reduce runoff and erosion?

Contour Ploughing

_ involves stepped fields on slopes that slow water flow and conserve soil.

Terraced Farming