Question

Metamorphic aureoles typically contain nonfoliated rock like hornfels because a. they form at shallow burial depths (less than 8 km). b. they form as a consequence of shearing without a subsequent change in temperature or pressure. c. they form adjacent to an intruding pluton, which provides heat for metamorphism. d. compressional forces associated with mountain building provide the necessary pressure to create hornfels.

Answer 1

Answer:

c. they form adjacent to an intruding pluton, which provides heat for metamorphism.

Explanation:

• In metamorphic rocks, the contact metamorphism produces the aureoles in the surrounding zones of the rocks that get altered.

• There varies in the thickness from the from centimeters to several kilometers like the large granitic intrusions and they typically consist of non foliated rocks formed due to the heat sources and intruding plutons.

Answer 2

Answer:

Option (C)

Explanation:

The metamorphic aureoles can be defined as an area forming a ring of metamorphic rocks that surrounds an uprising igneous intrusive body. The rocks that are formed here is hornfels which is a non-foliated rock, which is formed from the heat provided by the uprising magma body. This type of rock is formed in the region where there occurs contact metamorphism.

Thus, the correct answer is option (C).