Biogenic Gas Biogenic Gas: In geology, biogenic gas refers to natural gas that is the byproduct of the microbial decomposition of biological and organic matter. For instance, methane soil gas on Earth is typically a biogenic gas resulting from the decomposition of organic soil zones, landfills, marshes, and swamplands. Alternatively, natural gas can be petrogenic…

Anion Anion: In the fields of chemistry and geochemistry, an anion is a negatively charged ion. The oppositely charged ion is a cation.    

Intrusive Rocks In the volcanology branch of geology, intrusive rocks are igneous rocks that form and crystallize under the Earth’s ground surfaces, within other geologic formations. In fact, intrusive rocks form by the process of magma shooting through pre-existing sedimentary, igneous or metamorphic rocks. For instance, a pegmatite dyke or a batholith. On the other…

Growth Fault Growth Fault: In geology, a growth fault is a strike-slip fault or dip-slip fault that moves contemporaneously with deposition. This causes the throw (amount of vertical displacement) to increase with depth and the strata to be thicker on the downthrown side as compared to the upthrown side.

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…

Diagenesis Diagenesis: In geology, diagenesis refers to the physical and chemical changes of a sedimentary formation when compaction and lithification occur over time.