News Main Animals Archaeology Dinosaurs Earth History Human Animal Space Tech   Getty Images |   Commonplace Today An overview of Passu glacier in the Upper Hunza Region, Northwest Frontier Province, Pakistan. According to a new study, the world's first glaciers appeared when plate tectonics mysteriously shut off 2.4 billion years ago. Volcanoes went on a 250-million year hiatus, and the atmosphere cooled dramatically. | Discovery News Video   « back to article

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