ICS 1 Block 2 8/29-9/9
Day 3 Physical and Chemical Conditions of Rocks
Standard(s): ES 3. c. Students know how to explain the properties of rocks based on the physical and chemical
conditions in which they formed, including plate tectonic processes.
Objective (s): To understand the three main types of rocks, there chemical composition and physical conditions
that produce them
Pace
Warm-up
(10 min)
Information
Write agree with the statement.
Write disagree with the statement.
___The word crystalline means that atoms are arranged in a
repeating pattern.
___The two most abundant elements in Earth’s crust are
silicon and carbon.
___Color is always the best physical property to use when
attempting to identify minerals.
Notes
(20 min)
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Topic: Physical and Chemical Composition of Rock
o Rock classification
o Rock type
o Rock Processes
Wdoc: ics1 sem1 block 2 es3abc_seafloor_pt_rock_packet
Ppdoc: ics1 sem1 block 2 es3abc_seafloor_pt_rock_packet
Guided
Practice
(20 min)
3:45 min rock types
http://www.youtube.com/watch?v=fNLmBVBfn38&feature=related
Video: 3 min Rock types
Video: 10 min Rock cycle Foldable
http://www.youtube.com/watch?v=a4Rn5hpM0pM&NR=1
http://geology.com/rocks/
http://www.geolsoc.org.uk/rockcycle
Critical
thinking
(5min)
Practice
(20 min)
Reading / Questions:
Handout: Vocab crossword
Review
(5 min)
Summary, graphic organizer
Homework
(5 min)
Go over homework
Brochure page
Rocks Classification:
Composition-reflects the chemical constituents available when the rock was formed
Texture-is an indication of the conditions of temperature and pressure under which the rock formed
Texture types
o Grain size
o vesicular size
Rock types:
Igneous formed by cooling from molten material, have interlocking crystalline textures, hard rocks-compact,
some uniform, very dense, above and below ground, extrusive and intrusive
Granite, obsidian, pumice, quartz,
Sedimentary preexisting rock parts, have fragmental textures, soft rock-not as compact, some alignment, sand
grains on surface, worn a way by wind and water, layers deposited and build up, chemical and clastic types
Coal, limestone, sandstone, shale,
Metamorphic transformed by heat and pressure, minerals align, hard rocks-compact, heated
Gneiss, marble, quartzite, slate,
Rock possesses identifying properties that reflect its origin:
Rock Cycle Processes
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Weathering
Erosion and Transport
Deposition of Sediment
Burial and Compaction
Deformation and Metamorphism
Melting
Crystallization of Magma
Uplift
Plate tectonic processes directly or indirectly control the distribution of different rock types.
Subduction-takes rocks from close to the surface and drags them down to depths where they are subjected to
increased pressures and temperatures.
Tectonic processes also uplift rocks so that they are exposed to lower temperatures and pressures and to the
weathering effects of the atmosphere.
How were the rocks different
How were they the same what and why caught your eye?
Igneous Rocks
Igneous rocks are formed from molten rock called magma. They are mostly crystalline (made up of interlocking crystals) and usually
very hard to break.
Basalt
Basalt is made of fine-grained interlocking crystals (about 1mm in size). It is black or dark
grey in colour, and often contains vesicles – bubbles of gas trapped as the lava cooled.
Pumice
Pumice is formed when gas-rich magma froths up to form a sort of “mousse”. The lava is
glassy-looking and is so full of bubbles that it floats on water!
Gabbro
Barry Marsh, School of Ocean and Earth Science, University of Southampton
Gabbro is made of coarse-grained (5mm or so) interlocking crystals. Its overall colour is dark grey but it often contains glassy or palecoloured crystals of feldspar as well as dark minerals.
Granite
Barry Marsh, School of Ocean and Earth Science, University of Southampton
Granite is made of coarse-grained (5mm or so) interlocking crystals. It has more light coloured crystals than dark, usually of white or
pink feldspar, glassy quartz, and shiny mica.
Sedimentary Rocks
Sedimentary rocks are formed from sediment grains deposited by water, wind or ice. They are always formed in layers, called “beds” or
“strata”, and quite often contain fossils.
Conglomerate
Conglomerate is made up of rounded pebbles (>2mm) cemented together. They are
formed from sediment deposited by fast-flowing rivers or by waves on beaches.
Mudstone
Mudstone is made up of fine-grained clay particles (<0.05mm) compressed together.
Mudstones form where clay has settled out in calm water - in lakes, lagoons, or deep sea. Flaky mudstone is called shale.
Sandstone
Sandstone is made of sand grains (0.05-2mm) cemented together. It is formed from
sediment deposited by rivers, the sea, or by the wind, so there are many types of sandstone.
Limestone & Chalk
Limestone is made up of calcium carbonate (fizzes with acid). This may be shell
fragments, mud, or small, round ooliths that form in tropical lagoons. Chalk is a soft white limestone made from the microscopic
skeletons of marine plankton.
Metamorphic Rocks
Metamorphic rocks were once igneous or sedimentary rocks, but have been changed (metamorphosed) as a result of intense heat
and/or pressure within the Earth’s crust. They are crystalline and often have a “squashed” (foliated or banded) texture.
Slate
Slate is made of fine-grained interlocking crystals which lie flat in the same direction, known as the cleavage direction, along which the
rock easily splits.
Schist
Schist is made of medium-grained interlocking crystals. Its shiny appearance is due to the mineral mica. Crystals line up to give the
rock wrinkly layers – this is called foliation.
Gneiss
Gneiss is made of coarse-grained interlocking crystals. Crystals line up in pale and dark layers to give the rock a banded texture.
Marble
Marble (metamorphosed limestone) is made of calcium carbonate (fizzes with acid). It has
medium-grained Interlocking crystals with no alignment.
Crystallisation of Magma
Here are some multiple-choice questions to test your understanding:
1. What difference is there between the composition of Lava and Magma?
Magma contains dissolved gases and lava does not
Magma is solid and lava is a liquid
Lava is solid and magma is a gas
1
2. Which type of magma is most likely to erupt effusively from a shield volcano?
Cool, viscous (sticky) magma
Hot, runny magma
Magma that has already partly crystallised below ground
2
3. An igneous rock that is fine-grained or glassy must have:
Crystallised slowly
Cooled rapidly after erupting from a volcano
Formed deep underground
2
4. A sheet-like intrusion formed as magma pushes in between layers of rock is called:
a Batholith
a Dyke
a Sill
3
5. A pyroclastic flow is formed when an explosive eruption produces a dense mixture of:
Hot gases and volcanic ash (shattered rock and pumice)
Water and volcanic ash
Water and lava
Igneous Rocks
Here are some multiple-choice questions to test your understanding:
1. “Rocks that have formed by cooling of molten magma are called igneous rocks. All these rocks have …………… textures.” The
missing word is:
Crystalline
Fragmental
Rough
1
2. What property of granite makes it a good material to use for gravestones?
It contains several different minerals
It is hard and resistant to weathering
It is rough and can be used as an abrasive
2
3. What property of basalt makes it a good material to use for road surfaces?
It is hard and resistant to weathering
It is dark in colour
It can be polished to look attractive
1
4. What property of gabbro makes it a good material to use for worktops?
When broken it has a rough surface
It contains several different minerals
It can be polished to look attractive
3
5. Igneous rocks like granite are often used for street paving and kerb stones in city centres because:
They are hard and do not wear away easily
They contain several different minerals
They can be polished to look attractive
Sedimentary Rocks
Here are some multiple-choice questions to test your understanding:
1. Which one of the following sedimentary rocks fizzes with dilute hydrochloric acid?
Limestone
Sandstone
Mudstone
1
2. Which of the following rocks is used for making bricks?
Limestone
Sandstone
Mudstone
3
3. Which of the following rocks is used to make cement?
Sandstone
Limestone
Conglomerate
2
4. Many sedimentary rocks are good building stones because:
They contain several different minerals
They often contain fossils
They can be cut and carved to make large blocks
3
5. What type of soils would be treated with limestone to improve crop yields?
Acid soils
Neutral soils
Alkaline soils
Metamorphic Rocks
Here are some multiple-choice questions to test your understanding:
1. “Many metamorphic rocks re-crystallised deep in the Earth’s crust as they were heated and squashed up by immense forces. As a
result, these metamorphic rocks often have ……………… textures”. The missing word is:
Foliated
Fragmental
Rough
1
2. What property of slate makes it a good material to use for roofing?
It splits easily into thin sheets
It is dark in colour
It can be polished to look attractive
1
3. What property of marble makes it a good material to use for work-tops?
It is softer than steel
It can be polished to look attractive
It can be dissolved by weak acids
2
4. What property of gneiss makes it a good material for sea-defences?
It contains several different minerals
It can be polished to look attractive
It is hard and resistant to erosion
3
5. What property of marble makes it vulnerable to weathering processes?
It is impermeable (water cannot penetrate)
It can be polished to look attractive
It can be dissolved by weak acids