Question

13. Joints are

1. (a) mode I fractures.

2. (b) shear planes.

3. (c) discontinuities with visible movement on either side.

14. A dike transports magma

1. (a) across strata of the host rock.

2. (b) horizontally.

3. (c) not at all.

15. Metamorphism occurs at temperatures

Answer 1

Answer 13 : a) Mode I fractures.

Explanation : Joints are dilational or mode I fractures where there is no visible movement on either sides of the block.

Answer 14 : a) across strata of the host rock.

Explanation : A dike is a discordant intrusion that cuts across the host rock and transports magma across the strata.