|Describe one structural change that accompanies increasing metamorphism in the vicinity of a large intrusive igneous body.||HINT: Look at the diagram showing structural changes with metamorphism. Follow the changes that occur within an originally horizontal layer.|
|Describe two textural changes that accompany increasing metamorphism in the vicinity of a large intrusive igneous body.||HINT: Look at the series of micro-textural drawings. What happens to grain size? What happens to grain orientation? What happens to an originally clastic texture?|
|Explain under what circumstances melting is a by-product of changes that cause metamorphism.||HINT: Review Plate Tectonic Scenario 2.
In a sedimentary wedge caught between converging plates, increases in T and P may cause some rock types to metamorphose whilst others actually melt.
|Explain under what circumstances the presence of a melt causes the changes that result in metamorphism.||HINT: Review Plate Tectonic Scenario 3.
Where melts form above a descending plate and then rise into overlying crust, the rocks there may be metamorphosed by the intruding melts.