Augrabies GorgeAugrabies Falls National Park sits in the northwestern portion of the nation of South
Augrabies GorgeAugrabies Falls National Park sits in the northwestern portion of the nation of South Africa, close to the border with Namibia. The National Park is defined by the scenery of the Orange River, seen here flowing through the spectacular Augrabies Gorge.The river begins its course on flatter lands, where it weaves back and forth over sandy terrain, but within the park that changes. The river tumbles over the Augrabies waterfall, the erosive power of which has dug deeply into the granites of the area.The sharp edges of the canyon are made of the Augrabies Granites. The rocks are about 1.2 billion years old, created at a time of massive tectonic upheaval in the area that is today South Africa, possibly including a plume of hot mantle deep underground supplying heat and magma to the crust.Granites are strong rocks, tough to weather. You see some fractures in this shot; that’s the main way granite weathers, with water getting into cracks and breaking them apart. Sheets of granite will sometimes break off the walls and fall into the gorge along these fractures. The yellowish or dull color of the granite is another feature of how these rocks weather. Many of the minerals in these rocks, such as quartz and plagioclase, are colorless and so are easily stained. When a tiny bit of a colored mineral, most commonly iron oxides, coats these rocks, it changes the color to a dull yellow or darker rusty brown hue.-JBBImage credit: https://www.flickr.com/photos/nevilleslens/14957528072/Read more:http://www.gu.se/forskning/publikation/?publicationId=181050http://www.expertafrica.com/south-africa/augrabies-falls-national-parkhttp://bit.ly/1ypGHye -- source link
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