Science Olympiad Dynamic Planet Practice Test

What distinguishes a listric fault?

1. It has a linear fault plane

2. It curves with steep dip near the surface that becomes shallower

3. It is always a normal fault

4. It features lateral movement only

The correct answer is: It curves with steep dip near the surface that becomes shallower

A listric fault is characterized by its unique shape, which is primarily a curved fault plane. This type of fault exhibits a steep dip near the surface that transitions to a shallower dip at greater depths. This curvature in the fault plane is significant because it reflects the underlying geological processes that create such a fault system, often associated with extensional tectonics such as those occurring in rift zones. The movement along a listric fault is typically vertical, where one block of earth is driven upward or downward relative to another, illustrating its classification as a normal fault. The deformation associated with listric faults can lead to significant geological features like basins or half-grabens, especially in regions undergoing stretching of the Earth's crust. In contrast, the other options would not correctly characterize a listric fault. A linear fault plane does not account for the distinctive curvature, and it may represent other fault types. While listric faults often fit into the category of normal faults, not all normal faults are necessarily listric, making the assertion that it is always a normal fault too limiting. Lastly, the feature of lateral movement is more representative of strike-slip faults, rather than the vertical component of listric faults.