teaching - Earth Science Teachers' Association

TEACHING EARTH SCIENCES ● Volume 26 ● Number 3, 2001
The activities
The aim of this field trip is to stimulate interest in Earth
science rather than try to get them to learn lots of new
ideas. The beach south of the harbour at Saundersfoot
has a spectacular anticline (see front cover photograph)
that clearly illustrates the ideas that sedimentary rocks
form in layers and that these layers can be bent under
pressure. The first activity (see Figure 1 Task 1) asks the
pupils to draw the shape of the anticline and to decide
on the type of rock it is made of (sedimentary, igneous
or metamorphic). The quality of the field sketches is
usually quite poor at first but at least it makes the pupils
look at the rocks with a “scientific eye”. They examine
the rocks (avoiding all possible hazards such as overhanging
rocks) and estimate the dip of each limb.
Approximately 50 metres back towards the harbour
there is a small syncline in the cliff. This is much more
difficult to spot, but once the layers have been pointed
out the pupils can usually distinguish the structure. The
pupils can appreciate from this that you can have “up”
and “down” folds (see Figure 1 Task 2).
In the same region there are some faults. This time a
sketch is provided (see Figure 2 Task 3) and the pupils are
expected to estimate the distance that the rocks have
moved and to interpret this movement in terms of compression
or extension. Initially they find this quite difficult
but once the teacher has pointed out the sandstone marker
bed they can easily identify the sense of movement.
The final two activities involve simple observations on
the sand and the pebbles found on the beach (see Figure
2 Tasks 4 & 5). These exercises simply show the range of
different materials that can be found in a small area and
are designed to get pupils to think about their origins.
I am planning to introduce a new activity for next
year’s trip in which the pupils will measure and describe
the ripples found in the sand. This will lead towards some
new statements in the AQA double award syllabus.
Conclusion
Fieldwork is one of the great strengths of Earth science.
Pupils can learn that science is all around us and we can
“do science” in all of these environments - not just the
laboratory. The pupils get a lot out of the experience
and I feel that it is very worthwhile.
If you are involved in teaching the Earth science component
of the Key Stage 3 course, can you find a suitable
site for a field trip like this? If, on the other hand, you are
an Earth science specialist not involved in Key Stage 3
science, why not offer your services to your colleagues?
Owain Thomas
Teacher i/c Geology
Amman Valley School
Margaret Street,
Ammanford,
Carmarthenshire. SA18 2NW
Tel. (01269) 592441
Figure 2
111 www.esta-uk.org