Aerial photograph of Devils Tower,a basalt outcrop in Wyoming,USA. This massive rocky tower rises almost 300 metres above the plain. It was formed by the cooling of a plug of underground magma (molten rock) produced by a volcano around 60 million years ago. Erosion of the softer surrounding soil and rock over the centuries slowly exposed the hard rock,causing it to project above the surface. This image was taken during the National Geographic Society-US Army Air Corps stratosphere flight in the balloon 'Explorer II' in November 1935 | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / American Philosophical Society |
Taille de l’image : | 3397 px × 2569 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |