This Government of Manitoba article describes how glaciers helped to form bison rubbing stones. So how did these great big rocks end up in the middle of the prairie? Bison rubbine stones are what geologists call "erratics". Erratic stones are defined as rocks that are differenet compositionally from the rocks that form the surface on which they are found. Erratics were moved from their original homes by the formation of the glaciers thousands of years ago. As the ice formed it ripped chunks of stone and gravel from the earth and carried them across the landscape. Several thousand years later, the glaciers started melting. When the glacier was no longer able to carry the weight of the boulder, it was simply dropped. They were left scattered over the landscape, some the size of fieldstones, some car-sized and others as big as a house.

Students will learn about key points in Iowa’s agricultural history, while gaining writing and sequencing skills.

« Découvre la géologie, la chimie et l’écologie des lacs et des étangs. »

*Texte, images, illustrations, vidéo:

-Les écosystèmes lentiques
-Géologie
-Chimie
-Écologie

*Matériel annexe: vidéos (changements climatiques et vidéo satellite accélérée) et articles supplémentaires.

Photographer James Balog shares new image sequences from the Extreme Ice Survey, a network of time-lapse cameras recording glaciers receding at an alarming rate, some of the most vivid evidence yet of climate change. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 22-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

In this episode of Crash Course Kids, Sabrina gives us a real world example of how the Hydrosphere and Geosphere affect each other in the form of Weathering and Erosion. Think of Weathering as the force that makes a mess and Erosion as the force that cleans it up.