Development of tolerance. Over time, the brain adapts in a way that actually makes the sought-after substance or activity less pleasurable. In nature, rewards usually come only with time and effort. Addictive drugs and behaviors provide a shortcut, flooding the brain with dopamine and other neurotransmitters.
There are two types of metamorphism: contact metamorphism and regional metamorphism. Contact metamorphism is a type of metamorphism where rock minerals and texture are changed, mainly by heat, due to contact with magma.This is an easy name to recall if you remember that these rocks change by actually coming in contact with something very hot, like magma.egional metamorphism is a type of metamorphism where rock minerals and texture are changed by heat and pressure over a wide area or region. Contact and regional metamorphism differ in both the area and pressure involved.
Metamorphic rocks fall into two major categories: foliated metamorphic sedimentary rocks non-foliated metamorphic rocks. Refer to Metamorphic Rock Photos for more visual examples of each of these metamorphic rock types. Foliated (Layered) Metamorphic Rocks 1. slate Slate is metamorphosed shale.Slate is tougher than shale and it breaks into thin, flat layers.Slate is usually dark gray, but it can also be red colored.efer to Metamorphic Rock Photos for more visual examples of each of these metamorphic rock types. Foliated (Layered) Metamorphic Rocks 1. slate Slate is metamorphosed shale. Slate is tougher than shale and it breaks into thin, flat layers. Slate is usually dark gray, but it can also be red colored.