What is the size required for a particle to be called gravel?

Examples of high grade schist is _______

The small sized intrusives that occupy bends in the folds are called __________

Which rocks show severe degree of metamorphism?

What is the usual colour of gabbro?

The shape arch or dome is shown by which type of concordant body?

Porphyries are examples of which type of rocks?

Which rock is also called secondary rock?