From Earth Science On-Site
Tedbury Camp, Somerset
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 Vallis Vale and Tedbury Camp
List of the concepts needed
Sound knowledge and understanding of geological processes should form the basis of the preparatory lesson(s) at KS3 in school within the 1 to 2 weeks prior to the field visit.
KS3 geological processes
Time: 80 minutes
In broad terms the KS3 ‘geological processes’ is the study of the ‘Rock Cycle’.
Learning objectives for KS3
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:
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
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:
Teacher shows quick demonstrations of:
Objective 3. Sedimentary processes (35 minutes)
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:
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:
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:
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!).
The follow up work after the Vallis Vale / Tedbury Camp visit is 1) a summary of the rock cycles at Tedbury, or 2) a Building Stones Survey.
Summarising the Rock Cycles
Refer to the Rock Cycle Worksheet (pdf file, 46 KB)
Building Stones Survey
Using the ideas from the preparation exercises pupils conduct a survey of the use of different building materials in the area of the school, using the worksheets at the end of this document.
After the Earth Science On-Site visit, as a homework exercise, pupils are asked to describe in detail two uses of stone as part of a survey of building stone in the local area.
The term “building” may need to be very loose. Suitable sites could include a local church, gravestones (helpfully dated), school buildings, local walls, high street shop fronts, kerbstones, cobblestones, local monuments, bridges, and the pupil’s own home. In particularly unhelpful areas concrete, cement and bricks could be designated as “man-made” stone for the purpose of this exercise.
Teachers (or pupils) should identify two sites to work on (perhaps taken from the preparatory homework exercise above). Remind pupils about situations where permission is required, and appropriate behaviour is expected. Also, draw attention to thoughts about safety, if kerbstones, or a cobbled road is chosen.
Pupils should record: