2. Recapping from Junior Cert…
_____________ are formed from hot volcanic material that
has cooled down – two examples are __________ and
_______________.
________________ rocks are formed from particles of
animal or plant remains, or other rocks. Examples include
_______________ and ______________.
_________________ rocks are rocks that are changed by
great _____ or ___________. Examples include
____________ and _______________.
4. Igneous rocks
Formed underground (intrusive) or on the surface
(extrusive)
Two basic intrusive types
Plutonic – formed deep underground, with large crystals.
Example – Granite of Wicklow Mountains
Hypabassal – formed close to the surface, smaller crystals.
Example – Dolerite of Co. Antrim.
One extrusive type
Basalt (Giant’s Causeway)
5. Hypabassal Dolerite – Fair Head sill
Formed close to the surface, has an
appearance like Basalt. Crystals are
small.
6. Plutonic Igneous Rock - Granite
Contains many crystals due to slow
cooling underground as it was
formed. Found in the Dublin &
Wicklow mountains (Batholith)
8. Definitions & Examples
Extrusive ____________________________________________
Example of Extrusive rock ______________________________
Intrusive ____________________________________________
Hypabassal __________________________________________
Example of Hypabassal Rock ____________________________
Plutonic _____________________________________________
Example of Plutonic Rock _______________________________
13. Sedimentary rock - formation
Key words and phrases
Accumulation – build up of Strata (layers) of particles
Compaction – squashing of layers together
Cementation – glueing together of particles
Lithification – the process of changing sedimentation into
stone
14. Sedimentary Rock types
Organically formed from dead plant/animal material (e.g.
Coal, Limestone, Chalk)
Inorganically formed – from particles of other rocks (e.g.
Sandstone, Mudstone)
Chemically formed (less common) – formed from
evaporation of sea water, leaving the salts behind (e.g.
Gypsum, Rocksalt)
15. Gypsum – a chemically formed sedimentary
rock (from seawater evaporating)
17. Metamorphic Rocks – P 68
Three types:
Thermal (rocks changed by intense heat – e.g. Quartzite
(thermal metamorphism of Sandstone, Sugar Loaf
Mountain)
Dynamic Metamorphism – (rocks changed by pressure –
e.g. Shale into slate)
Regional Metamorphism – (rocks changed over a long time
and over a large area, being slowly “cooked” to form new
rocks e.g. Gneiss. Found in N. Scotland, NW Ireland and
Canada)
23. Rock Cycle – P 62
http://www.youtube.com/watch?v=U7YQ5vwaL98
The process by which rocks are constantly “recycled” by
the natural processes of the Earth.
28. Case Study - Tara Zinc and Lead
mines
An important Primary Economic Activity in the GDA (Greater
Dublin Area)
At Tara Mines people interact with the Rock Cycle in many
different ways
Constructing Shaft Mines
Working on new methods to extract ore
Inventing safe methods to dispose of mining waste
Developing transport systems to move ore to the market
30. Zinc and Lead - uses
Zinc
Used in alloys for car manufacture
Galvanising
Dietary supplements
Batteries
Lead
Soldering
Bullets
Batteries
35. Tara Mines
Largest Zinc Mine in Europe, 5th largest in the world
Ore (rock that contains the metals) is extracted at Navan,
shipped to refineries in Finland and Norway
The ore was formed approx 350 million years ago between
layers of carboniferous limestone, now lies 500 to 900m below
surface
“Stope and Pillar” mining is used (see p 66)
Rock is crushed to a powder, mixed with water and chemicals
to remove the metals from the rock
Waste water is toxic, needs to be treated carefully
37. Tara Mines - Environment
Mining is potentially very dangerous for environment
Sediments and chemicals used are vulnerable to transport
by wind – can get blown onto crops, towns, people
Since 1997 improvements have been made at the mine to
improve the local environment
Waste water treated by natural bacteria
Landscaping in local area
Restoration of tailings pond (where sediments are allowed
to settle)
Constant monitoring for pollution
38. LC Exam Question on mining
(2009)
Discuss, with reference to one of the following, how humans
interact with the rock cycle (30 marks)
Mining
Extraction of building materials
Oil / Gas exploitation
Geothermal energy production
Marking Scheme
Interaction identified: 2 marks
Discussion: 14 x SRPs
Give credit for up to two examples of location.
39. LC Exam Question 2009
Examine, with reference to examples from Ireland, the
formation of sedimentary rocks. [30m]
Marking Scheme
Name two sedimentary rocks: 2 + 2 marks
Name two associated Irish locations: 2 + 2 marks
Examination: 11 x SRPs
Give credit for 1 SRP for diagram without annotation.
Give credit for extra labelling in diagram from Examination
SRPs.
Allow treatment of up to 3 rocks in examination.
At least 3 SRPs for treatment of second sedimentary rock
If description only –2 x SRPs max