Rock layers and relative dating

Most sedimentary rocks are laid down in flat, horizontal layers. These can later tilt and fold due to tectonic activity, and river cuttings can cause gaps among the layers. Geologists are able to ‘read’ the rock layers using relative and absolute dating techniques. Relative dating arranges geological events – and the rocks they leave behind – in a sequence. The method of reading the order is called stratigraphy (layers of rock are called strata).

In this activity, students observe rock layers located near Whanganui, watch an animation about how they were formed and use relative dating to work out the order in which rocks were created. The activity offers literacy opportunities as well as practice using the science capability ‘Interpret representations’.

By the end of this activity, students should be able to:

• observe, discuss and compare rock layers in a photo and a diagram

• use reading skills to correctly label an interactive rock layer diagram

• use oral and written language skills to narrate a video animation about rock layer formations.

Download the Word file (see link below) for:

• background information for teachers

• teacher instructions

• student instructions.