Orange (colour) and absorb mostly greenish-blue light. (See also shades of orange). Other orange pigments include: The orange colour of carrots, pumpkins, sweet potatoes, oranges, and many other fruits and vegetables comes from carotenes, a type of photosynthetic pigment. These pigments convert the light energy that the plants absorb from the sun into chemical energy for the plants' growth. The carotenes themselves take their name from the carrot. Autumn leaves also get their orange colour from carotenes. When the weather turns cold and production of green chlorophyll stops, the orange colour remains. Before the 18th century, carrots from Asia were usually purple,
Paired metamorphic belts of plate tectonics in the late 1960s, led to a better understanding of regional metamorphism and permitted the association between paired metamorphic belts and subduction zones. The asymmetric deformation of earth's lithosphere along subduction zones produces two distinct thermal environments. These two distinct thermal conditions are parallel to the trend of the subduction zone. Low temperature, high pressure conditions are generated in the areas along the oceanic trench, whereas high temperature, low pressure conditions are generated beneath the arc region. A positive thermal gradient is visualized, extending from the colder oceanic trench to the warmer arc region. The thermal and