Figure 12.29

Folding. (A) These folded volcanic rocks are located in Hamersley Gorge, Karijini National Park, Australia. The distance across this photo is only a few tens of meters. (B) A satellite image of kilometers-long folds in sedimentary rocks in the Béchar Basin, northwestern Algeria. These rocks were folded in a continental collision between the African and Eurasian plates beginning about 65 million years ago. The ground distance of this satellite image is approximately 100 km (60 mi) across.

(A. © Ignacio Palacios/Lonely Planet Images/Getty Images; B. Image courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center)