Since only a small area surrounding the intrusion is heated by the magma, metamorphism is restricted to the zone surrounding the intrusion, called a metamorphic or contact aureole. Outside of the contact aureole, the rocks are not affected by the intrusive event.ataclastic metamorphism occurs as a result of mechanical deformation, like when two bodies of rock slide past one another along a fault zone. Heat is generated by the friction of sliding along such a shear zone, and the rocks tend to be mechanically deformed, being crushed and pulverized, due to the shearing.
Symptoms of oral allergy syndrome include itchy mouth, scratchy throat, or swelling of the lips, mouth, tongue, and throat. Itchy ears are sometimes reported. The symptoms are usually confined to one area and do not normally progress beyond the mouth.
Some likely causes are: 1  Though they donât seem to be caused by bacteria or viruses, they can be triggered by an allergy to bacteria commonly found in the mouth.6 They may occur with viral infections. 2  A fault in the immune system can cause it to attack normal cells in the tongue and mouth.7.