River Pebble Geology

Today we joined our friends at the Grose river for a geology class led by...me! First the children collected as many different rocks as they could. We then classified the rocks by size into boulders, cobbles, pebbles, granules, and sands. We used a grain size chart to help us.

We then talked about how the rocks had got to the area and the different types of currents that had transported them.

We then grouped the rocks according to roundness (see chart top of page) and discussed why some were more rounded than others including the distance they had travelled and their hardness.

We then had a look at the sands and gravels and I encouraged the children to name their sample. Most came up with "poorly sorted very course sand". We talked about how giving a description and a name for their sample would help other scientists to understand what they were talking about.

Finally we had a quick discussion about what the rocks sands were made from and how they would be changed in the rock cycle.