Teaching sequence

Lesson objective

In this lesson students carry out simple classification of rock types and identify characteristics of soil and relate these to rock type. Students define the terms ‘weathering’ and ‘erosion’ and understand how these affect landscapes and landforms.


Review the terms relating to rocks and the rock cycle from the previous lesson.

Review the different types of rocks and explain that different rocks have different properties such as crystal type and grain size.

Model the classification of a rock using the learning object Start your rock collection.

Explain that geologists classify rock specimens in great detail; however, explain that they will only need to be able to understand simple classification of rocks.


  1. Allocate a rock sample to each student or group of students.
  2. Show students the worksheet Rock hounds – identifying types of rocks (PDF, 388 KB) 
  3. Ask each group to use a magnifying glass to identify their rock sample.
  4. Share information about the types of rocks identified and the properties that were identified and discuss with students the different types of soil that they may be familiar with. Explain to students that soil is formed from rocks and that rock type and soil type is related.
  5. Use the learning object Soil types to assist in showing students the characteristics of soil.
  6. Show students samples of different types of soil and show how they can be classified according to their grain size and composition – as per rocks.
  7. Mix water with each soil sample, shake and set aside to allow soil to settle into layers.
  8. Explain how having a basic understanding of the different types of rocks and soils assists in understanding how landscapes (rocks and soils) weather and erode. Explain that there are different types of weathering.
  9. Watch the video Weathering and erosion http://studyjams.scholastic.com/studyjams/jams/science/rocks-minerals-landforms/weathering-and-erosion.htm to introduce the concepts of weathering and erosion.
    Teacher note: be aware that the term ‘chemical weathering’ is not indicated in the ACARA curriculum documents; therefore the term ‘weathering by naturally produced chemicals’ is used in this unit.
  10. List the causes of physical weathering and show examples of each.
  11. List the causes of weathering by naturally produced chemicals and show examples of each OR show students images of different types of weathering from the gallery below.
  12. Examine how weathering affects rock landscapes by showing examples of weathering on Uluru that clearly show varying types of weathering. Type ‘Uluru’ into Google maps and then zoom in to see weathering on the surface of the rock.
  13. Review the term ‘erosion’ and clarify the difference between weathering and erosion. Explain how erosion changes landscapes and landforms over time. This includes acute short-term and long-term effects. Revisit the images of Australian landforms used in Lesson 1 to illustrate these effects.

Images of different types of weathering.

Weathering by naturally produced chemicals.
Thermal stress - exfoliation.
Water weathering.
Plant and Lichen erosion.
Wind and Water weathering.
Weathering from freezing and thawing


Explain how weathering and erosion of the landscape can make fossils, rocks and gems visible at the surface. Inform students that Professor Ruby has easily found gemstones in dry and eroded creek beds just by washing and sifting through the soil.

Inform students that weathering and erosion can also reveal fossils. Palaeontologists can do further excavation to ‘dig up’ the fossils. Students complete the learning object Colossal fossils: the dig to illustrate how fossils are found and classified.

Lesson Resources


Student activities

Digital resources

Start your rock collection,
Annenburg Learner. Learning object 

L4 Soil types, NDLRN. Learning object 

Weathering and erosion,
Study Jams. Video 

Google Maps, Google 

L2011 Colossal fossils: the dig,
NDLRN. Learning object 


Rock hounds – identifying types of rocks (Word, 388 KB)

Useful links

L14 Mineshaft,
NDLRN. Learning object. 

L926 Down to Earth – Rock back in time,
NDLRN. Learning object 

Wikipedia. Information for teachers 

Weathering and erosion - geology for kids,
KidsGeo.com. Information and images for students