1. Summary – Chapter 1 (Plate Tectonics)
Layersof the Earth
Two types of Crust – OCEANIC & CONTINENTAL
Oceanic – Dense, Heavy Rock (SIMA). Basalt
Continental – Less Dense (SIAL). Granite & other rocks
Plate Tectonics is the theory of how the Plates of the Crust move. It was developed by
combining the Theories of Continental Drift (Wegener) and Sea Floor Spreading (Hess).
Plates move by convection currents in the mantle.
Three Categories of Plate boundaries:
1. Destructive (Plates Collide, destroying crust through subduction). These can be
Oceanic-Oceanic Plate collisions (forming Island arcs & trenches), Oceanic-
Continental collisions (trenches and volcanoes), Continental-Continental collisions
2. Constructive (Plates Separate forming new land & mid ocean ridges)
3. Transverse (Plates Scrape past each other, land neither created nor destroyed,
forming earthquakes ONLY)
2. Summary Chapter 2 (Earthquakes)
Earthquakes can occur at any plate boundary, but the most powerful ones occur at
destructive and transverse plate boundaries.
Shallow earthquakes – less than 70 km deep (Strong)
Intermediate – 70-300 Km deep
Deep – 300K+ (Weaker)
1. P Waves/Compressional Waves (fast, little damage)
2. S Waves/Shear Waves (slower, more damage)
3. Love/Rayleigh Waves (Slow, most damage)
Earthquakes are recorded on:
1. Seismographs (instruments)
2. Richter Scale (most accurate, uses seismographs)
3. Modified Mercalli Scale (less accurate, uses observation)
Effects of Earthquakes
Short term: Death & injury, damage to buildings/infrastructure/water & sanitation, fire,
Long Term: Economic loss, disease, breakdown of law and order & government, social
3. Summary Chapter 3 (Volcanoes)
Volcanoes can occur at destructive plate boundaries (violent), Constructive Plate
Boundaries and Hotspots (less violent). NO VOLCANOES AT TRANSVERSE PLATE
Volcanoes can be active, dormant (asleep) or extinct (dead).
Products of Eruptions:
1. Lava (sticky & acidic at destructive PBs, runny and basic at hotspots and constructive
2. Pyroclastic flows (hot ash mixed with gases, very fast moving & destructive)
3. Poisonous gas
4. Ash, Pumice and Dust
5. Water Vapour
6. Lahars (pyroclastic flows mixed with snow)
External/Extrusive Landforms (Rock is Basalt):
1. Plateaus (e.g. Giants Causeway)
2. Cones (Dome from sticky lava eruptions, Shield from runny)
3. Calderas (huge “craters” formed when a magma chamber collapses)
4. Volcanic Plugs (hardened core of a volcano)
Internal/Intrusive Landforms (Rock is Granite):
1. Batholiths (magma chambers)
2. Sills (magma moves between rock layers)
3. Dykes (magma slices across rock layers)
4. Laccoliths & Lopoliths (dome structures)
Effects of Volcanoes:
Negative: Lava flows, Lahars (mudflows), Pyroclastic flows, Poison gas, flooding (eruptions
under glaciers), Tsunamis. All cause death, injury and damage to infrastructure.
Positive: New Land (e.g. Iceland), Geothermal energy, fertile soil, mineral deposits, tourism
Predicting Volcanic Eruptions
1. Ground deformation (bulges from magma moving)
2. Historical Patterns of eruptions
3. Seismic activity (earthquakes caused by magma flows)
4. Gas analysis (e.g. increased levels of Sulphur Dioxide in the area)
4. Summary Chapter 4 (Folding & Faulting)
Folds are caused when rock layers are compressed (pushed together) and bent by tectonic
forces. Faults are caused when rock layers are split, either by compression or tension
Two periods of folding in Ireland:
1. Caledonian Folding (400mya, NE to SW, Leinster)
2. Armorican Folding (300mya, E to W, Munster)
Types of Faults
1. Normal (caused by tension, land slips down)
2. Reverse (caused by compression, land slips up)
3. Thrust (caused by compression at a shallow angle)
4. Tear (movement at right angles to rock layers)
1. Rift Valleys (Graben), formed when land slips down between parallel faults.
2. Block Mountains (Horst), formed when land is pushed up between parallel faults.
3. Domes, formed when melted rock is pushing up rock layers.
5. Summary Chapter 5 (Rock Types and their formation)
Three Rock categories:
1. Igneous (from volcanic activity, underground = intrusive, overground = extrusive)
2. Metamorphic (changed from heat or pressure)
3. Sedimentary (particles squashed and cemented together)
Plutonic: Deep underground, cools slowly. Example - Granite.
Intermediate: Close to surface, cools quicker. Example - Dolerite.
Extrusive: On surface, cools quickest. Example – Basalt.
Organic: Formed from remains of dead animals, Example - Fish bones form limestone
Inorganic: Formed from other rock fragments, Example - Sandstone, mudstone.
Chemically formed: Formed from evaporation of water, leaving behind salt crystals.
Thermal: Rocks changed by exposure to heat. Example – Sandstone to Quartzite
Dynamic: Rocks changed by exposure to pressure. Example – Limestone to Marble
Regional: Combination of thermal and dynamic over a large area. Example - Granite to
The Rock Cycle (how rocks are created, destroyed and
cycle by mining(e.g.Tara
6. Summary Chapter 6 (Weathering andErosion)
Weathering is the process by which rocks are broken down into smaller fragments. Erosion
involves the rock particles being transported away (e.g. by rivers, wind, glaciers or the sea)
Types of Weathering
a. freeze-thaw, formed when water in gaps in rock freezes and expands, causing
it to crack (see below).
b. exfoliation or onion weathering, caused when the surface of the rock peels
off layer by layer (see below)
c. Salt Crystallisation, growth of salt crystals in a rock causes it to split.
a. Carbonation – CO2 causes rainwater to become acidic which dissolves rock
b. Hydration – minerals in rock swell on contact with water, shattering rock
c. Oxidation – minerals react with oxygen, e.g. Iron particles rusting in rock
d. Hydrolysis – acidic water reacts with minerals in certain rocks
Biological weathering refers to the action of living organisms in the breakdown of rocks, e.g
tree roots, burrowing animals breaking down rocks.
Erosion also involves the process of Transportation and Deposition, e.g. a rock may be
weathered by being hit off other rocks in a river (attrition), the particles of rock may then be
transported by being dragged along a river bed (traction) before being dropped (deposited)
in a new place.
7. Chapter 7 Rock Types and Landscapes
Landscapes are affected by the underlying rock type. A rock that is weathered easily (such as
Limestone) will create a different landscape to a more resistant rock (such as Granite)
Irish example: The Burren (A Karst Landscape, where Limestone is exposed at the surface)
Limestone is Permeable (allows water to pass through it) and contains vertical cracks
(fissures) and horizontal cracks (bedding planes)
1. Limestone Pavement – the surface of bare rock. Composed of Clints (blocks) and
2. Swallow Holes – the point at which a river disappears underground. Spotted on OS
maps when a river suddenly disappears.
3. Dolines/Sinkholes – Depressions on the landscape where an underground cavern has
collapsed. Also visible on OS Maps as circular contour features (don’t confuse with
4. Turloughs – disappearing lakes caused by the rise and fall in the water table.
1. Caves/Caverns – underground passages formed by erosion of rivers. Irish examples:
Ailwee Cave, Marble Arch Cave.
2. Stalactites – as carbonation weathers limestone, the dissolved material (calcium
bicarbonate) is carried underground. It can be deposited on the roof of caves as
calcite. Over time it builds up to form an icicle like formation.
3. Stalagmite – formed the same way as stalactite except calcite is deposited on the
floor of a cave.
4. Column/Pillar – when a stalactite and a stalagmite join up
8. Chapter 8 Fluvial Processes
The rate at which rivers erode the landscape is affected by the volume, velocity, steepness
of slope and river depth.
The sediment carried by a river is its load.
Hydraulic action (force of water)
Abrasion/Corrasion (rocks wearing down the river bed)
Attrition (rocks smashing into each other)
Solution (river chemically dissolves the soft rock)
Solution (invisible microscopic grains of material)
Suspension (visible small grains eg sand)
Saltation (rocks bouncing along river bed)
Traction (rocks being dragged along the bed of the river)
Reduction in velocity (such as a river entering a lake)
Increase in load size (e.g. a landslide into the river)
Reduction in volume (e.g. fromevaporation)
A river profile is a “cross section” of a river. A profile can be long (showing roughness) or
graded (smoothed out).
Drainage Patterns of a River:
A) Dendritic (tree like)
B) Trellis (right angled)
C) Radial (from a central point)
D) Deranged (no obvious pattern)
9. River Features
V-Shaped Valleys (upper stage, erosion)
Interlocking Spurs (upper stage, erosion)
Waterfalls/Gorges (upper stage, erosion)
Meanders (Middle stage, erosion & deposition)
Oxbow lakes and meander scars (middle stage, erosion & deposition)
Flood Plains (lower stage, deposition)
Levees (lower stage, deposition)
Deltas (lower stage, deposition)
Humans interact with rivers in the following ways:
Building dams (e.g. Three Gorges, China)
Changing the course of rivers (e.g. canalisation of Rhine)
Building flood prevention measures (e.g. Ennis & Athlone, Ireland)
River Rejuvenation (Higher Level)
This refers to how a river can gain velocity and “become young again”. It happens when the
sea level drops or land rises. The river gains speed and begins to flow faster over what was a
mature/old age landscape, creating new landforms such as:
River Terraces – gives the valley a “stepped” appearance
Incised meanders - “cut in” to the landscape
Superimposition (Higher Level)
This refers to rivers which do not seemto follow the normal “rules” of rivers – cutting
through hills and ridges rather than flowing around them. Usually formed by tectonic uplift
(folding) on an existing landscape – as folding is very slow the river is able to cut through the
folds as they are being formed.
10. Summary of Chapter 9 – Glacial Processes
Glacier ice is formed by accumulation of snow at a greater rate than ablation (melting).
Compression by snow above creates a type of airless, hard ice called firn or neve.
Sliding/basal flow – the base of the glacier melts under pressure, increasing its
Plastic flow – a glacier can “melt” around an obstacle
Rotational slip – Ice slips around a central point
Types of Glaciers:
Cirque or Corrie – formed in a hollow high up on a mountain
Valley – when a glacier spills out of a cirque and travels downhill
Piedmont – a large glacier formed from the merger of several valley glaciers
Ice Sheet – when piedmont glaciers join to cover the entire landscape
Erosion Processes of Glaciers:
Plucking – when the glacier base melts into the ground, refreezes and then “plucks”
Abrasion – stone fragments in glaciers scrape the ground they pass over
Deposition by glaciers:
Material deposited by glaciers is called drift. Material can either be unsorted (just randomly
dropped) or sorted by meltwater streams.
Glacial erosion landforms:
1. Corrie/Cirque (a mountaintop hollow) – Devil’s Punchbowl, Kerry
2. Arête (a ridge between two Corries) – Lough Bray, Co. Wicklow
3. Pyramidal Peak (a mountaintop that has had several corries on different sides) –
Currauntoohil, Co. Kerry
4. U-Shaped Valley (a V shaped valley widened and steepened by glaciers) –
5. Ribbon Lake – (a lake in the floor of a U shaped valley) - Glendalough
6. Hanging Valley (a tributary valley which was not deepened by glaciers – Glendalough
7. Fiord – a U-Shaped valley flooded by the sea - Killary Harbour, Mayo
Powerpoint notes can be found at www.slideshare.com/noelhogan
11. Glacial Deposition Landforms:
1. Boulder Clay Plain (flat land covered with glacial till) – Ireland’s Central Plain
2. Moraine (material “bulldozed” by glaciers into ridges of till) – The Midlandian
3. Drumlin (egg shaped hills of glacial till) – outside your window!
4. Erratic (Rocks transported by glaciers and deposited when it melts) – The Burren
5. Kettle Holes – (hole formed by a large mass of buried ice melting, creating a hollow
in the landscape) - Wicklow
Fluvioglacial deposition landforms (deposited by meltwater):
1. Outwash plains (like boulder clay plains but the material is sorted) – The Curragh
2. Eskers (ridges of material left behind by meltwater rivers, also sorted) – Esker Riada
A nunatak is not strictly a glacial feature, but is a mountain top sticking up above an ice
12. The Concept of a Region Chapter Summary
Definition of a region: An area that has particular characteristics that set it apart from other
Basic indicators of regions are:
7. Urban Regions
Climate Regions – these include tropical (such as the Amazon Rainforest Biome in Brazil),
Temperate (Ireland and Paris Basin) and Mediterranean (Mezzogiorno in Italy).
The climate of Ireland and the Paris Basin is influenced by the Atlantic Ocean (keeps it from
getting too hot or cold), Prevailing wind (brings rain) and distance from equator. These
combine to give a Cool Temperate Maritime climate
Brazil’s climate is Tropical or Equatorial – Hot and Wet
Mezzogiorno’s climate is warm with seasonal (mostly winter) rainfall (Mediterranean)
Landscape Regions – Similar rocks and relief. The Burren and the North Atlantic Plain (both
covered in more detail elsewhere, the Paris Basin is part of the North Atlantic Plain)
Administrative Regions – Regions made by drawing lines on a map – e.g. Counties and
county councils in Ireland, Regions, Departments and Communes in France.
Cultural Regions – Defined by language or religion – Gaeltacht in Ireland, Flanders (Flemish)
and Wallonia (French) in Belgium. Can lead to conflict, e.g. in Northern Ireland.
Regions of Industrial Decline – Areas where factories have closed - Sambre Meuse valley in
Economic Regions – Core/Rich (Greater Dublin Area, Paris Basin), Peripheral/Poor
13. Peripheral Irish Region Summary
The West Region: Galway, Mayo and Roscommon. This region is underdeveloped, has a
small and dispersed population with high levels of outward migration, a relatively
unfavourable climate and is distant from large markets.
Climate: Cool, Temperate, Oceanic. High Rainfall which leads to much waterlogging and
poor drainage. Rainfall up to 2,500 mm/yr. Relief rainfall over mountains is common. Small
temperature range – 6 to 15 degrees. North Atlantic Drift keeps temperatures relatively
Relief: Mountainous in the west, more low lying in east Galway and Roscommon.
Caledonian folding created these mountains. Glacial deposits which affects drainage in
many areas. Coast is heavily eroded.
Drainage: High rainfall = waterlogging. Many rivers and much deranged drainage.
Soil: Poor quality. Peaty in upland areas, most of the rest is podzols and gleys. Very little
Brown Earth (fertile) soil).
Primary Economic Activities: Forestry is common, with much Sitka Spruce plantations.
Farms are small (25 hectares average) and relatively uneconomic, with low levels of
mechanisation. Mostly cattle and sheep. Agri-tourism growing in popularity as farmers seek
a second income. High Rainfall causes waterlogging and leaching in soils, and upland areas
are suitable for sheep and forestry only. The region has a small domestic market and is
remote from the big EU markets. One advantage the area has is for fishing, with the Atlantic
14. Ocean providing a rich resource. Rossaveal in Galway is the largest fishing port. Gas is
exploited off the coast of Mayo (Corrib Gas Field)
Secondary Economic Activities: Small, mostly located near the larger urban areas. The small
labour force, undeveloped (but improving) infrastructure and distance from major markets
has led to an overreliance on traditional industries and government/EU support. The
Government has published several strategies (National Development Plan, Decentralisaton)
to try and support the West.
Tertiary Economic Activities: Transport is generally poor, with only one airport (Knock).
Galway is the only county with a motorway link to Dublin. Rail transport is limited, with no
rail line connecting the three counties. Galway suffers from traffic congestion and has been
bypassed. No major port. Tourism is a major sector but suffers from seasonality (summer
Population: Region suffered from outmigration since the famine. There has been some
population increases since 1973 however the area is vulnerable to emigration during
15. Core Region: The Greater Dublin Area Chapter Summary
This is a rich area characterised by favourable climate, proximity to markets, a large and
skilled labour force and good infrastructure.
It consists of the Counties of Dublin, Meath, Kildare and Wicklow
Climate: Cool Temperate Oceanic but has significantly less rainfall than the West (Rain
Shadow Effect). Slightly warmer summers than the west, but winters are slightly colder.