Twinning Definition Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.

Mafic Definition In geology, “mafic” is a term that describes an igneous rock that has an abundance of darker color minerals.

Subsidence “Subsidence” is a geologic condition, in which a localized mass movement occurs, resulting in the downward settlement of the earth over time. When subsidence occurs, the actual ground surface elevation is lower. This occurrence of the ground surface sinking is typically caused by groundwater table and aquifer reductions, by which the soils become more…

Troposphere Troposphere: The troposphere of a terrestrial planet is the lowest member of the atmosphere. On Earth, the troposphere starts atop the ground surface and terminates roughly 10 kilometers above mean sea level. In fact, geologists understand that most of the Earth’s water vapor (clouds) exists in the troposphere. And the next member of the…

Direct Shear Test A Direct Shear Test is a geotechnical engineering laboratory procedure that measures the shear strength value of a soil sample.

Licensed Professional Geologist A “Licensed Professional Geologist” or a “Certified Professional Geologist” is a person who is certified by a State and/or Federal agency (such as the California Department of Consumer Affairs, Board for Professional Engineers, Geologists & Land Surveyors), and has proven be educated, formally trained and professionally competent per government standards, to practice…