Question

Match each term with its definition by writing the letter of the correct definition in the right column on the line beside the term in the left column. 5. fault a.the number of years since a rock has formed6. extrusion b.a break in Earth’s crust7. unconformity c. the way to determine relative ages of rocks8. relative age d.a hardened layer of magma beneath Earth’s surface9. law of superposition e. the age of a rock compared with the age of other rocks10. intrusion f. fossils used to help geologists match rock layers11. absolute age g. the surface where new rock layers meet a much older rock surface beneath them12. index fossils h.a hardened layer of lava on Earth’s surface

Answer 1

Answer:

Fault- B

Extrusion- H

Unconformity- G

Relative Age- E

Law of Superposition- C

Intrusion- D

Absolute Age- A

Index Fossils- F

Explanation:

Fault- A fault generally refers to the fracture as a result of which either the hanging wall goes up or down with respect to the footwall. it takes place either due to compressional or extensional stress. In simple terms, it is a break that occurs in the earth’s crust.

Extrusion- These are the consolidated rocks that are formed when magma comes out to the surface forming extrusive rocks. For example, Basalt and Rhyolite.

Unconformity- It is defined as the period of non-deposition. It occurs when the rocks surfaces are eroded extensively.   These are the surfaces where the much older rock meets geologically younger rocks.

Relative age- When the age of any rock is compared with the age of different rocks then, the relative age of the rock is obtained. It is extensively used for the calculation of the age of rocks from any sedimentary sequence.

Law of Superposition- This law enables us to evaluate the relative ages of two or more rocks as it depicts the younger rocks that are deposited on the apex and the older rocks at the bottom of a sequence.

Intrusion- These are the rocks that form due to the crystallization and solidification of magma beneath the earth's surface. For example, granite and gabbro.

Absolute age- This refers to the total amount of time (in terms of years) that a rock has formed. These rocks are formed from the deposition, compaction, and lithification of sediments in a sedimentary environment.

Index fossils- These are the fossils that were present for a shorter period of time and have a wide geographical distribution and were mostly used by the geologists in order to match the rock layers.