Normal Fault Normal Fault: In the field of geology, a normal fault is a type of dip-slip fault where the hanging wall moves downwards from the footwall. The average dipping angle of a normal fault ranges from 45 to 90 degrees. Normal faults are the opposite of reverse faults. Detachment Fault Detachment Fault: A detachment…

Degree of Saturation (SR) “Degree of Saturation” (SR) is an engineering geology term and refers to the ratio of the volume of water to the total volume of void space. The Degree of Saturation or SR-value ranges from 0% to 100% (0% being completely dry, and 100% being fully saturated). Degree of Saturation Formula Degree…

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

Mineraloid Definition The term “mineraloid” refers to a natural earth substance that appears to be similar to a genuine mineral, although lacks any form of internal structure and crystal form. Nonetheless, a mineraloid does comprise true minerals within it. For instance, Fire Opal and Blue Opal are not minerals because they are amorphous (do not…

Liquid Limit (LL) “Liquid Limit (LL)” in the field of geological engineering, refers to the upper limit of the “plastic state.” This is a separation of the plastic phase and viscous liquid phase when measuring soil consistency. Mathematically, it is the water content (basing on the percent of dry weight), at which two sections of…

Extrusive Rocks Extrusive Rocks: In the volcanology branch of geology extrusive rocks are igneous rocks that have been erupted onto the Earth’s surface, before forming and crystallizing. On the other hand, intrusive rocks form and crystallize under the Earth’s ground surface. Extrusive rocks are typically microcrystalline and aphanitic, because of the faster rate of cooling…