From Earth Science On-Site
The Ercall, Shropshire
KEY STAGE 3 PREPARATION AND FOLLOW-UP IDEAS
© GeoconservationUK ESO-S Project, 2013
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.
In-school learning in preparation for field visit to the Ercall Quarries
List of the concepts needed
KS3 knowledge and understanding of geological processes should form the basis of the preparatory lesson(s) in school within the 1/2 weeks 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
- be able to describe and explain ways in which rocks are weathered
- be able to observe and describe the key features of a rock specimen, including colour, texture and mineral content
- be able to classify specimens of common rock types, using observed features, as igneous, sedimentary or metamorphic, and name such common rock types
- be able to describe and explain how sedimentary rocks may be formed by processes including the erosion, transport and deposition of rock fragments
- 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.
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
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.
The Rock Cycle
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
Animations under the heading “The formation of fundamental rock types” are useful resources
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.
Teacher shows quick demonstrations of:
- sedimentation jar filled with water then 3 charges of different sediment (the last one being muddy to show slow fall of sediment)
- a volcano in a laboratory. This demonstration of a volcano uses wax and sand. Details are available from Earth Science Education Unit
- 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
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.
How did sediment become hard rock? This can be modelled for sandstone, as shown on the Joint Earth Science Education Initiative website
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.
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.
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
Teacher shows a demonstration of the formation of ripple marks using a fish tank (approximately 100cms long, 50cms deep and 50cms wide) and two wooden cylinders 3cm diameter and slightly longer than the width of the tank
Put clean, well sorted sand of fine to medium grain size into the tank, sufficient to line the floor of the tank to a depth of several cm. Place the tank on the wooden rollers, and fill the tank with water to a depth of 15-20cm. Gently and rhythmically rock the tank back-and-forth in an oscillatory motion until ripples form on the sediment surface. (This does not take long, but there is the potential for disaster if the tank is rocked too vigorously!).
- ↑ www.geos.ed.ac.uk/undergraduate/field/holyrood/spheroids.html
- ↑ academic.brooklyn.cuny.edu/geology/leveson/core/topics/weathering/picture_gallery/display/new_jersey_garret_mt_1.html
- ↑ www.au.au.com/cameras/images/devils-marbles.jpg
- ↑ www.thewalkzone.co.uk/Lake_District/walk_36/180203h.jpg
- ↑ The Rock Cycle www.washington.edu/uwired/outreach/teched/projects/web/rockteam/WebSite/rockcycle.htm.htm
- ↑ The formation of fundamental rock types available from earthsci.org/rockmin/rockmin.html
- ↑ A volcano in a laboratory www.earthscienceeducation.com/workshops/worksheet_index.htm
- ↑ The effects of pressure on rockswww.earthscienceeducation.com/workshops/rock_cycle/metamorphism.htm
- ↑ How did sediment become hard rock? www.chemsoc.org/networks/learnnet/jesei/sedimen/index.htm
- ↑ www.kented.org.uk/ngfl/subjects/geography/rivers/Teacher Plans/whatiserosionanddeposition.htm