“Effective Size” (D10) is an engineering geology term. Effective Size represents a diameter that directly corresponds to the percentage, by weight, of grains that equal to 10% on the grain-size diagram. To illustrate, 10% of the soil sample particles are finer-grained, and 90% of the sample particles are coarser than the “effective size.”
Mafic Definition In geology, “mafic” is a term that describes an igneous rock that has an abundance of darker color minerals.
Diagenesis Diagenesis: In geology, diagenesis refers to the physical and chemical changes of a sedimentary formation when compaction and lithification occur over time.
Index Fossil Definition An Index fossil, in the field of paleontology, refers to a fossil that identifies and dates the stratigraphic unit that it is observed to exist in. Index fossils can combine a wide geographic range. And they can really narrow down the classifications of most stratigraphic units.
Single Station Methane Gas Detector Single Station Methane Gas Detector: As per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a single station methane gas detector is a device consisting of electrical components that are capable of measuring methane soil gas concentrations indoors, and initiating an alarm. The single…
Triggered Creep In the field of geology, the term “Triggered Creep” refers to a type of creeping landslide, usually along a fault line, that is triggered by a source of seismic activity.
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…
