This set of Engineering Geology Problems focuses on “Important Metamorphic Rocks – 02”.
1. Marble is formed from which rock?
Explanation: Marble is essentially a granular metamorphic rock composed chiefly of recrystallized limestone. It is characterized by a granulose texture but the grain size shows considerable variation in different varieties.
2. Marble is composed of which mineral?
Explanation: Marble is composed chiefly of mineral Calcite (CaCO3) in its crystallised form. Small amounts of many other granular minerals like olivine, serpentine, garnet and some amphiboles are also present in many varieties.
3. What is the colour of biotite schist?
Explanation: Since the biotite is metamorphosed to form biotite-schist, the colour is not changed much and hence the colour of biotite-schist is also black.
4. What is the special property test for identification of marble?
a) Scratch test
b) Alkali test
c) Acid test
d) pH test
Explanation: As the marble is rich in calcite, it readily reacts with acids and this itself it is a test to distinguish marble from other metamorphic rocks. Usually, HCl is used.
5. Identify the metamorphic rock formed by thermodynamic method of metamorphism.
Explanation: Gneiss is a unique metamorphic rock which is formed by the thermodynamic process of metamorphism. Whereas the other rocks are either formed by thermal or dynamic methamorphism.
6. Pick the characteristic of gneiss which is wrong.
a) Gneiss does not take polish
b) Gneiss also comes in banded structure or texture
c) Pink gneiss is also observed at many places
d) Gneiss takes polish well
Explanation: Gneiss is a metamorphic rock which sometimes is found to have bands. It is also found to appear in pink-grey colour. Gneiss is known to take excellent polish and hence used as blocks for construction.
7. State true or false. The slatic cleavages are shown by slate.
Explanation: Slate is an extremely fine-grained metamorphic rock characterized by a slaty cleavage by virtue of which it can be readily split into thin sheets having parallel smooth surfaces.
8. Quartzite is formed from which rock?
a) Pure shale
b) Pure Basalt
c) Pure sandstone
d) Pure Granite
Explanation: Metamorphic quartzites result from the recrystallization of rather pure sandstones under the influence of contact and dynamic metamorphism.
Sanfoundry Global Education & Learning Series – Engineering Geology.
To practice all areas of Engineering Geology Problems, here is complete set of 1000+ Multiple Choice Questions and Answers.