(Redirected from List of longest bridges in the world) This is a list of the world's longest bridges more than three kilometres long sorted by their full length above land or water. Span refers to the longest spans without any ground support. Note: There is no standard way to measure the total length of a bridge.
But the smaller crystals mean that the rest of the cooling happened very quickly. If a rock has both crystal types, it means that the mamga spent some time in a magma chamber, where the large crystals grew, then was violently erupted onto the surface, where the small crystals were formed.
The inside of the Earth is very hot - hot enough to melt rocks. Molten (liquid) rock forms when rocks melt. The molten rock is called magma. When the magma cools and solidifies, a type of rock called igneous rock forms. What are they like? Igneous rocks contain randomly arranged interlocking crystals. The size of the crystals depends on how quickly the molten magma solidified. The more slowly the magma cools, the bigger the crystals. You may have done an experiment at school with a substance called salol. If molten salol cools slowly, you get big crystals. If it cools quickly, you get small crystals. Obsidian and basalt. If the magma cools quickly, small crystals form in the rock. This can happen if the magma erupts from a ...