Rising 120 meters above Lake Michigan, Sleeping Bear Dunes in Michigan are formed by sand that is blown atop glacial moraines, and are referred to as perched sand dunes. Much of the sand is composed of uniform quartz particles that are blown from the adjacent lakeshore and highlands. Lake Michigan is one of the five Great Lakes of North America, and the second largest. These freshwater lakes were formed about 10, 000 years ago when great ice sheets, two miles thick, retreated following the last ice age. | |
Licence : | Droits gérés |
Crédit : | Science Photo Library / Matulavich, Peter |
Model Release : | Non requis |
Property release : | Non requis |
Durée : | 16 Secondes |
Aspect ratio : | 4/3 |
Restrictions : | - |