Color it is viewed, may alter its perception considerably; for example, a low-intensity orange-yellow is brown, and a low-intensity yellow-green is olive green. The color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Physically, objects can be said to have the color of the light leaving their surfaces, which normally depends on the spectrum of the incident illumination and the reflectance properties of the surface, as well as potentially on the angles of illumination and viewing. Some objects not only reflect light, but also transmit light
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