PH/KS4/Prep

From Earth Science On-Site

< PH | KS4
Jump to: navigation, search
Esos100.gif

Park Hall Country Park, Stoke-on-Trent

KEY STAGE 4 PREPARATION AND FOLLOW-UP IDEAS
© GeoconservationUK ESO-S Project, 2014


It is anticipated that the ideas and materials presented here will be adapted by schools, and others, to be more appropriate for their own purposes and programmes of study.

In such circumstances please acknowledge the source as the Earth Science On-Site project.

Key Stage 4 Downloads
Follow-up Worksheet (PDF)
Animation 1 (EXE 12.1mb)
PH4_KS4_clip.exe (EXE 4.9mb)

Contents

In-school learning in preparation for field visit to Park Hall

Revision of KS3 knowledge and understanding of geological processes should form the basis of the preparatory lesson(s) in school within the week prior to the field visit.

KS3 geological processes Time: 80 minutes

In broad terms KS3 ‘geological processes’ is the study of the ‘Rock Cycle’.

Learning objectives for KS3

  1. be able to describe and explain ways in which rocks are weathered
  2. be able to observe and describe the key features of a rock specimen, including colour, texture and mineral content
  3. be able to classify specimens of common rock types, using observed features, as igneous, sedimentary or metamorphic, and name such common rock types
  4. be able to describe and explain how sedimentary rocks may be formed by processes including the erosion, transport and deposition of rock fragments
  5. be able to make reasonable suggestions as to how a common sedimentary rock type they have described was formed, and how long the process took.

Objective 1. Weathering (10 minutes)

As the basis of a brief question and answer session, use photographs of rocks that have suffered weathering. Suggested images:

  • boulder(s) showing onion-skin weathering
  • boulder(s) split in half – e.g. Devil’s Marbles
  • jagged, broken rocks on mountain ridges, preferably with patches of snow still visible.

An internet search yields many possible images for classroom use[1][2][3][4]

Some internet images provide useful background discussion about the weathering mechanisms involved. Tasks in small groups: show the pupils the photographs and give them one minute to come up with suggested causes of the weathering depicted in each image. There is probably no single ‘correct’ answer in any of these situations because weathering is rarely one process operating on its own. Weathering is usually caused by a combination of physical and chemical weathering processes. It is the pupils’ suggestions and subsequent discussion generated that are important. If pupils do not suggest chemical weathering, the teacher may need to pump-prime the discussion by asking them whether chemical changes might be possible in any of these examples.

Objective 2. The rock cycle (35 minutes)

This session is based on the rock cycle. A simplified pictorial version of the rock cycle should be used in the session and this diagram can be downloaded[5]

Animations under the heading “The formation of fundamental rock types” are useful resources[6]

Activity 1

Provide a set of six common rock types (sandstone, shale, conglomerate, granite, dolerite/basalt with crystals just visible, slate or schist or gneiss). Tasks in small groups:

  • agree key features of each specimen (colour, texture, etc.), and whether sedimentary, igneous or metamorphic
  • provide a set of name labels; groups have to decide quickly which label belongs to each specimen, and be able to justify (for able groups, provide more name labels than specimens!)
  • plenary agreement on correct labelling and why the name label is appropriate.
Activity 2

Teacher shows quick demonstrations of:

  1. sedimentation jar filled with water then 3 charges of different sediment (the last one being muddy to show slow fall of sediment)
  2. a volcano in a laboratory. This demonstration of a volcano uses wax and sand. Details are available from Earth Science Education Unit[7]
  3. effects of pressure on rocks. This simulation of the distortion of fossils by metamorphism uses modelling clay and cockleshells. Details are available at Earth Science Education Unit[8]
    Task for small groups using the rock cycle diagram:
    • decide what part of the rock cycle each demonstration is modelling
    • decide at which point in the rock cycle each specimen would have been formed
    • agree on the rough timescale needed for each rock type to have been formed, including the difference, for sedimentary rocks, between time for deposition and time for a deposit of loose sediment to be turned into a hard rock, and also how that may happen.
Activity 3

How did sediment become hard rock? This can be modelled for sandstone, as shown on the Joint Earth Science Education Initiative website[9]

Objective 3. Sedimentary processes (35 minutes)

Activity 4

Pupils place cubes of sugar in a closed container and shake for 30 seconds and then observe changes to the shape and size of the cubes. Repeat activity at 30 second intervals, weighing & measuring the cubes at each stage. Tasks in small groups:

  • decide what is the cause of the changes they have observed
  • decide what part of the rock cycle is modelled in the experiment
  • agree what will affect the degree of rounding and size reduction of rock fragments in the rock cycle.
Activity 5

Provide three piles of sediment (one of gravel, one of soil and one of sand) and watering cans for pupils to use to pour water over the sediments to see how far the water spreads the sediment. Tasks for pupils work in small groups:

  • agree what needs to be done to ensure the test will be a fair test
  • pour 2 litres of water slowly over each pile of sediment
  • observe what happens and measure how far the water spreads each pile
  • agree which type of material was spread further
  • predict what would happen if they poured 4 litres of water over each pile of sediment.
Activity 6

Teacher shows demonstrations of river erosion, transport and deposition using a child’s slide extension or a very long tray covered with a sand and gravel (pea-sized) mixture.

Tasks for pupils in small groups:

  • decide how the different types of sediment are moved along the river bed in this model
  • agree where erosion takes place and what evidence shows that erosion has occurred here
  • agree where deposition occurs and why deposition occurred at this place
  • decide what different results they could expect to see if (a) the slope of the tray is increased and (b) a greater volume of water is poured into the tray.

Details of Activities 5 and 6 (and of related practical activities) were available[10]

In-school learning following field visit to Park Hall

The knowledge and understanding of geological processes gained on the field visit needs to be consolidated and extended.

Learning Objectives

  • consolidation of understanding of the processes by which sedimentary rocks are formed
  • be able to relate this understanding to how the mode of formation of sedimentary rocks determines their texture and the minerals they contain
  • consolidation of understanding of the processes by which rocks are deformed
  • be able to relate this understanding to the general pattern of behaviour of materials under tensional forces
  • be able to deduce the time sequence of geological events from the pattern of observations made in the field

Park Hall field sketches

Each pupil is now provided with definitive copies of the completed Park Hall field sketch exercises for sites C & E to compare with their own attempts, and to put into their notes. These are found at the end of documents PH9 KS4C and PH9 KS4 D&E.

The Park Hall field sketches can be used to remind pupils about the evidence that can be used to work out the mode of formation of the sedimentary rocks at Park Hall. Pupils could watch PH4_KS3_clip.exe - a short animation with narration which tells the story of pebbles and sand in the Play Canyon at Park Hall:

Please note: this narrated animation is an .exe file, and although this file is safe to download, some computer systems may prevent you from doing so. It is also very large (12.1MB) - please consider whether you want to download a file of this size.

It may be helpful to use ”Sediment Video Movies”[11], which illustrates how sediment may be transported and deposited in different sedimentary environments (including in braided streams).

Deformation of rocks

Depending on how much discussion and modelling of faulting was carried out at Park Hall, part of this session could be devoted to modelling of deformation processes.

In KS3, pupils are likely to have investigated the behaviour of springs and rubber bands when they are stretched. Under lower stresses, both show a linear relationship (known as Hooke’s law) between force (load) and extension. This is called elastic deformation. However as the stress increases, the behaviour of the two materials begins to differ; neither obeys Hooke‘s law any more, but the spring becomes permanently deformed, while the elastic band becomes much more difficult to stretch further, and eventually snaps.

Activity 1

Teacher shows quick demonstrations of:

  • elastic deformation by gently bending a plastic ruler
  • plastic deformation by bending a metal strip by hand until it becomes permanently bent
  • brittle fracture by bending an old plastic ruler so hard that it snaps.

A useful site showing faults and animations of different types of faulting is on the PhysicalGeography.net FUNDAMENTALS eBOOK[12]

Deducing a geological sequence

The Park Hall field sketches can now be used to deduce the geological history of the rocks at Park Hall. This can be done as a small group activity, prompted by a sequence of questions. Alternatively, pupils could watch PH4_KS4_clip.exe - a short animation with narration which continues the story of the Play Canyon at Park Hall - and then be prompted by a sequence of questions.

Please note: this narrated animation is an .exe file, and although this file is safe to download, some computer systems may prevent you from doing so. It is also very large (4.9MB) - please consider whether you want to download a file of this size.

Each pupil should be provided with a copy of the rock cycle to remind them of the processes and events involved.

In the table below statements 1 to 8 show the sequence of events beginning with the oldest.

Statement Comment
1. Pebbles and sand grains were transported by rivers flowing from the south and were moved over long distances. The pebbles and sand grains are rounded and smooth indicating long-distance transport by water.

The most common pebbles are composed of quartzite and quartz; this is because quartz is a hard mineral that resists abrasion during transport over long distances.

Evidence that rivers flowed from the south is the occurrence of pebbles of rock that originated from the borderlands of South Wales, S.W. England and N.W. France.

2. Layers of pebbles and sand were deposited in flash floods. Deposits accumulated in a hot desert approximately 250 and 215 million years ago in the Triassic period when Britain lay just north of the Equator.

The sand grains are coated with clay that contains a red iron oxide called haematite. The presence of haematite is strong evidence that the sediments were deposited in an oxidising environment on land.

The pebbles and sands were deposited by flash floods and in intermittent braided river channels. (Fossils are rare in these deposits: hot deserts with flash floods are not the best environment for living things and even worse for preserving them!)

Some of the layers of sand and gravel were deposited in thick horizontal beds. At the edge of sand and gravel bars the moving sediment avalanched down the slope, driven by sediment-laden water and formed cross bedding. The cross bedding slopes northwards, indicating a river flowing from the south.

3. Sediment was buried below later sediments. Layers were buried, sediment was compacted and excess water was squeezed out.
4. Sediment became hard rock and sandstone and conglomerate were formed. Grains of sand and pebbles were cemented together by silica, which was precipitated from solution by circulating groundwater.

(Sandstone and conglomerate were formed by this process of lithification).

n.b. The silica cement in the rocks at Park Hall is weak and this gives friable sandstones and loose gravels in this quarry. This was an advantage when the quarry was worked for aggregates because the pebbles could be easily extracted.

5. The sandstone and conglomerate layers were buried deep in the Earth.  
6. The layers of rock were tilted. The rocks at Park Hall are tilted by about 10 degrees to the east.
7. Layers of rock were faulted. Faults were formed by tensional forces. These faults are described as normal faults.

In the Play Canyon faulting had dropped the pebble beds to a lower level on the western edge of the quarry.

8. The layers were uplifted.  
9. The layers of rock were weathered and eroded. These processes are still in action today
10. And finally … Humans mined and quarried the rocks in the area. The Play Canyon is an abandoned quarry. The quarry was mainly worked for the pebble beds, which were used as aggregate (gravel). Quarrying ceased because it was uneconomic to work the pebble beds.

Further quarrying will not happen. The site is a Site of Special Scientific Interest (SSSI).

Further work on time sequencing

Further teaching and learning on the topic of sequencing geological events can be found on the Joint Earth Science Education Initiative website[13]

Homework activity based on time sequencing of geological events at Park Hall

This homework is about how the Park Hall quarry formed. Each pupil should be provided with a copy of the Pupil Homework Answer Sheet (there is a copy at the end of this document) giving statements about events that happened before, during and after the formation of the rocks at Park Hall. The pupils may find it useful to look at a copy of the rock cycle to remind them of the processes taking place. A simplified pictorial version of the rock cycle can be downloaded[5].

The pupils use the completed field sketches for sites C and E, decide in what order these events happened and are asked to place the sentences in the correct order (oldest first). The statements are:

A. The layers of rock were uplifted
B. Sediment became hard rock and sandstone and conglomerate were formed.
C. The layers of rock were tilted to the east.
D. The layers of rock were weathered and eroded.
E. Pebble and sand layers were buried below later sediments.
F. Layers of pebbles and sand were deposited in flash floods in a desert.
G. Layers of rock were faulted.
H. The sandstone and conglomerate layers were buried deep in the Earth.

Pupils are then asked to tell the story of the layers of sedimentary rock at Park Hall. The teacher can suggest that they can do this by writing out the sequence of events, by drawing cartoons to illustrate what happened, by making a presentation or by writing a poem.

Homework answer for Park Hall.

F. Layers of pebbles and sand were deposited in flash floods in a desert.
E. Pebble and sand layers were buried below later sediments.
B. Sediment became hard rock and sandstone and conglomerate were formed.
H. The sandstone and conglomerate layers were buried deep in the Earth.
C. The layers of rock were tilted to the east.
G. Layers of rock were faulted.
A. The layers of rock were uplifted
D. The layers of rock were weathered and eroded.

References

  1. www.geos.ed.ac.uk/undergraduate/field/holyrood/spheroids.html
  2. academic.brooklyn.cuny.edu/geology/leveson/core/topics/weathering/picture_gallery/display/new_jersey_garret_mt_1.html
  3. www.au.au.com/cameras/images/devils-marbles.jpg
  4. www.thewalkzone.co.uk/Lake_District/walk_36/180203h.jpg
  5. 5.0 5.1 The Rock Cycle www.washington.edu/uwired/outreach/teched/projects/web/rockteam/WebSite/rockcycle.htm.htm
  6. The formation of fundamental rock types available from earthsci.org/rockmin/rockmin.html
  7. A volcano in a laboratory www.earthscienceeducation.com/workshops/worksheet_index.htm
  8. The effects of pressure on rockswww.earthscienceeducation.com/workshops/rock_cycle/metamorphism.htm
  9. How did sediment become hard rock? www.chemsoc.org/networks/learnnet/jesei/sedimen/index.htm
  10. www.kented.org.uk/ngfl/subjects/geography/rivers/Teacher%20Plans/whatiserosionanddeposition.htm
  11. Sediment Transport Movies faculty.gg.uwyo.edu/heller/sed_video_downloads.htm
  12. Types of faulting www.physicalgeography.net/fundamentals/10l.html
  13. Sequencing geological events www.chemsoc.org/networks/learnnet/jesei/sequenc/index.htm


Top of Page

© GeoconservationUK ESO-S Project, 2014
Site created by Salticus Web-hosting
Sponsors:
National Stone CentreNSC
ESTAESTA
GeoconservationUKUKRIGS
Natural EnglandNatural England
This page was last modified on 28 December 2008, at 17:28. This page has been accessed 1,292 times.