Vallorbe’s caves

Experience 1 : How were the caves formed?

We think the caves of Vallorbes were shaped by erosion, so we’ll do an experiment to prove it.

Photo Photo

Water without CO2 Water with carbon dioxyde

Explanation of the first experiment :

Carbon dioxide is present in the rain when it crosses the air. In our experiment the CO2 is represented by the sparkling water.The chalk in the experiment represents the rock And in the other tube we put water without CO2.The sparkling water will dissolve all the chalk and the water without CO2 will not dissolve the chalk.

Experiment 2 : How were the stalactites formed?

After some weeks the salt moved down on the thread and has solidified

Explanation of the 2nd experiment :

When water goes underground the CO2 goes back into the cave’s atmosphere So the elements (calcium carbonate) present in the underground can fuse to form a stalactite.

The stalacmites are formed by the rest of the elements present in the dropping water of the stalactites.

In our experiment we put 2 glasses of water with salt inside and we put a thread which joins the 2 glasses