Earth and Environmental Science year 11 yearly

Geosphere

the landforms, rocks, and minerals found on the surface and inside the earth

Atmosphere

a layer of gas and suspended solid surrounding the earth and keeping it safe from solar radiation

Hydrosphere

all the water on a planet

Lithosphere

the upper layer of the earth, including the crust and upper mantle

Asthenosphere

the weaker and more dense layer below the lithosphere

Density

how tightly a material is packed together

Composition

the overall makeup of the earth

Structure

How the components are put together. (inner core, outer core, mantle, upper mantle, lithosphere)

Accretion

The coming together and cohesion of matter under the influence of gravitation to form larger bodies

Conservation of angular momentum

Objects (and arms and legs) will be pulled towards the centre of a rotating body (like ice skaters), linking to the creation of planets and suns

Big Bang Theory

proposes that the creation of all matter occurred about 14 billion years ago, with all matter from the singularity moving outwards rapidly to form the universe

Protostar

formed when dust and gas in a nebula collapse due to gravity, with the central core becoming hot and glowing dimly

Planets Formation

Leftover dust from supernovae stars collide to form planetesimals, which eventually shape into planets

Moon Formation

4.5 billion years ago, the Earth collided with another planet, and the debris formed into our moon

Seismology

the study of earthquakes and their shock waves, detected and recorded by a seismometer

Meteoroids

objects in space that don't pass through the atmosphere

Meteors

shooting stars, space junk that burn up in the upper atmosphere but don't land on Earth

Meteorites

the parts of meteors that survive as they go through the atmosphere to eventually land on Earth

Meteorite Types

Iron (3%), Stony (95%), Stony-iron (<2%)

Earth's Layers

Identified through seismology, magnetism, and density variations

Zircon Crystals

Oldest naturally occurring mineral on Earth, found in igneous and sedimentary rocks, resistant to geological events

Radiometric Dating

Determining rock age by radioactive isotopes, half-life, and daughter/parent isotopes

Relative vs. Absolute Dating

Relative: stating rock age compared to others; Absolute: approximating specific rock age

Isotope Decay

Includes Alpha, Beta, and Gamma decay, used with half-life to determine material age

Problems with Radioactive Dating

Rock cycle can reset ageing process, oldest rocks recycled, affecting dating accuracy

Minerals Definition

Basic chemicals forming rocks, classified by physical and chemical properties

Crystal Definition

Materials with microscopic lattice structures, can be organic or inorganic

Physical Characteristics of Minerals

Include colour, habit, hardness, density, lustre, cleavage, and streak

Silicates vs. Non-Silicates

Silicates contain silicon, high melting points; Non-silicates lack silicon

Mafic Minerals

Rich in magnesium and iron, dark in colour, form under high pressure and temperature

Felsic Minerals

High silica and feldspar content, light in colour, form under lower pressure and temperature

Carbonates

Minerals with carbon as a building block, e.g., malachite and calcite

Calcite

Reacts with acid to form carbon dioxide, found in limestone and marble

Metal Ores

Mineral deposits mined for extracting metals, e.g., malachite (copper), galena (lead), bauxite (aluminium)

Rock Types

Igneous, sedimentary, and metamorphic rocks formed through different processes

Igneous Rocks

Formed from molten minerals, classified by cooling rate and location of formation

Sedimentary Rocks

Formed from compressed sediments, classified as clastic, chemical, or organic

Strata

Layers of rock

Clastic sedimentary rocks

Form from sediments cemented together, classified by grain size indicating deposition speed

Lithification

Compaction or cementation of sediment turning it into rock

Conglomerate

Clastic sedimentary rock with large round pebbles and smaller grains, formed in rivers with fast currents

Breccia

Clastic sedimentary rock made of angular fragments with gaps filled by smaller minerals or cement

Sandstone

Clastic sedimentary rock composed of sand-size grains, often containing fossils and clear layers

Mudstones

Containing clay minerals, quartz, and feldspar, classified by grain size into claystone and siltstone

Shale

Clastic sedimentary rock made of fine sediment, formed in quiet water environments

Chemical and organic sedimentary rocks

Formed by chemical precipitation or biological activity

Limestone

Rock with at least 50% calcium carbonate, fizzes with acid, can form via chemical precipitation

Rock salt

Consists of halite, formed by evaporation of salt water

Gypsum

Soft sulphate mineral composed of calcium sulphate dihydrate, formed in bedrock

Coal

Formed from compressed organic plant matter in freshwater swamp conditions, containing energy

Metamorphic rocks

Formed from existing rock changing due to heat and/or pressure, altering texture, crystal size, and alignment

Foliated metamorphic rocks

Receive pressure from one direction, showing visible layers like gneiss

Non-foliated metamorphic rocks

Receive pressure from all directions or none, lacking visible layers like quartzite

Contact metamorphism

Occurs when magma contacts existing rock, producing non-foliated rocks like marble and quartzite

Marble

Non-foliated metamorphic rock from limestone, fizzing with acid due to calcium carbonate

Quartzite

Non-foliated metamorphic rock from quartz sandstone

Regional metamorphism

Affects rocks over a large area due to extensive heat and pressure, common near convergent boundaries

Rock cycle

Processes transforming the main rock types into one another

Soil

Mixture of organic and inorganic matter, air, water, and minerals

Soil horizons

O, A, E, B, C, and bedrock layers from surface down

Mechanical/Physical Weathering

Breaking of rock into smaller fragments

Chemical weathering

Chemical changes minerals undergo with water, oxygen, and other chemicals

Topography

Slope of the land

Leaching

Washing away of soluble substances

Soil texture

Determines soil aeration, infiltration, and nutrient/moisture holding capacity

Non-renewable

Cannot be replaced within a human lifetime

Renewable

Can be replaced within a convenient time

Sustainable resources

Resources that can be used forever

Resource

Substance usable by humans

Economic

Mining cost lower than selling price for profit

Subeconomic

Mining cost too high for profit

Reserves

Available resource amount extractable at current cost and selling prices

Bauxite Ore

Aluminium Ore

Ash

Sand and clay in coal, incombustible, resulting in residue

Petroleum

Organic compound mix divided into crude oil and natural gas

Ore deposits

Rock volumes with elements in concentration for economic extraction

Uranium

Used for power generation through nuclear fission

Relative dating

Determining if one strata is older or younger than another

Law of superposition

Oldest rocks at the bottom, progressively younger towards the top in undisturbed layers

Law of cross-cutting

Rock body cutting or crossing is younger than the strata layers

Law of Lateral Continuity

Sediment spreads horizontally, same strata expected on either side of a disturbance

Principle of original horizontality

Deformed layers are not horizontal, moved after formation due to crustal movement

Principle of faunal succession

Relative age determined by fossils, top layer organisms appeared after those below

Index fossils

Distinctive fossils defining a geologic time period

Principle of inclusions

Fragments in a rock are older than the rock they are found in

Absolute dating

Actual age in million/billion years based on radiometric dating

Jigsaw continental shelves

the continental shelves seem to fit together like a jigsaw suggesting they were once connected and have since drifted

Identical fossils

The same fossils found in different continents and oceans away, suggesting the land masses were once connected

Ocean floor profile

mid-ocean ridges provide a how-to the continents moving

Sea floor rock age

youngest rocks are found along mid-ocean ridges and become progressively older as distance increases, with no rock on the seafloor older than 200 million years

Magnetic field

As Magma rises to the surface at mid-ocean ridges, the magnetic minerals align with the earth's magnetic field, showing evidence for seafloor spreading

Who proposed the theory of continental drift

Alfred Wegener

Arthur Holmes developed what idea?

the idea that convection currents in the mantle moved continents

Folds

the process where compression forces lead to layers of rock buckling, with types including Anticline and Syncline

Overturned fold

happens when one side is pushed over the other due to disproportionate compression

Recumbent fold

happens when one side of a fold is pushed to a point where it becomes nearly parallel with the other side

Fault

a crack in the earth's crust

Normal fault

when rocks are pulling apart, with one side moving down relative to the other

Reverse fault

happens when rocks are pushed together, with one rock pushed up relative to the other, often resulting in an overhang

Transform fault

movement is horizontal with the blocks of rock