Ultramafic Definition In the study of geology, the term “ultramafic” refers to an igneous rock that comprises up to 90% mafic minerals, or more.

Rigidity Definition Rigidity – In geotechnical engineering and engineering geology, rigidity represents the ratio of the shear stress and the amount of angular rotation that it produces, within a rock sample.

Topple Definition Topple – Slope movement due to forces that cause an overturning moment about a pivot point below the center of gravity of the unit.

Aphanitic Definition Aphanitic: In geology, the term aphanitic describes the texture of plutonic or volcanic igneous rocks, with grains that are not visible to the naked eye. In fact, an aphanitic texture is usually the result of faster cooling and solidification of liquid magma.

Stratosphere Stratosphere: The stratosphere of a terrestrial planet is the second-lowest member of the atmosphere. On Earth, the stratosphere starts atop the troposphere at approximately 10 kilometers above mean sea level, and terminates roughly 50 kilometers above mean sea level. In fact, geologists understand that the Earth’s ozone layer exists within the stratosphere, which absorbs…

Listric Fault Listric Fault: In the field of geology, a listric fault refers to a fault with a curved fault plane. Most listric faults comprise a steeply dipping section near the surface. But the fault plane becomes increasingly flat with depth. Listric faults can be normal faults or reverse faults.