What colour was the world in the past?

'What colour was the world in the past? Using rock evidence and ‘the present is the key to the past’ to colour the geological world'.

Earth’s surface colours today are produced by the same processes that operated in the geological past. Since the features that made up past geological landscapes were coloured in the same ways as today, many of these landscapes must have had the same combination of colours as Earth’s surface today.

This activity is a discussion, using the colours of unweathered surface rocks and ‘the present is the key to the past’ to give a coloured picture of past geological worlds.

Lots more activities can be fund on our website.

How many sand grains are there on a beach?

New ELI today 'How many sand grains are there in a bucket – or on a beach? Planning activities to estimate the number of sand grains in a bucket – or on a beach'

This ELI is a planning exercise to estimate large numbers of very small items. There are at least two different ways of making this estimation, each with different routes, both involving some simple maths.

Other Earthlearningideas involving calculations can be found in 'Teaching strategies' on our website.

Rock identification

Often wondered which rock is which? Earthlearningidea has updated the Virtual Rock Kit. As the image shows you can see every rock in hand specimen, close-up, in thin sections, where it can be found and how it can be used.

The ELI Team will add extra rocks from time to time. You can also find many activities for teaching about rocks on our website by using the alphabetical index or the search engine.

Weighing a dinosaur?

The new ELI today is 'Let’s weigh that dinosaur! How can a plastic model reveal the mass of an actual dinosaur?'

This Earthlearningidea is a class activity to estimate the mass of a dinosaur using a plastic model. It provides one method of estimating the mass of an extinct animal. The result can be compared with textbook values and with results obtained by alternative methods, based on measurements such as the depth of animal footprints (as demonstrated in 'How to weigh a dinosaur') or the size of the thigh bone.

Other ELIs related to dinosaurs and fossils in general, can be found in the Earthlearningidea 'Evolution of life' category.