Reverse Fault: In the field of geology, a reverse fault is a dip-slip fault in which the hanging wall moves upwards, relative to the footwall. The average dipping angle of a reverse fault ranges from 45 to 90 degrees. However, if less than 45 degrees, it becomes a “thrust fault.” Reverse faults are the opposite of normal faults.
Hydrogen Sulfide Soil Gas (In Natural Gas) Hydrogen Sulfide: Hydrogen sulfide (H2S) soil gas geologically occurs upon the thermal and microbial decomposition of subsurface organic material deposits. It is typically identifiable in biogenic and petrogenic natural gas sources, along with higher concentrations of methane soil gas. Additionally, nitrogen, oxygen, hydrogen, ethane, and isobutane exist within…
Leaking Underground Storage Tank (UST) Leaking Underground Storage Tank (LUST): A leaking underground storage tank (LUST) is a known case of hazardous liquid materials released into the environment, from within an underground storage tank (UST) source. The term “LUST” commonly applies to gasoline station soil contamination cases overseen by environmental regulatory agencies. Also See: Underground…
Contact Metamorphism Contact Metamorphism – Metamorphism is associated with the intrusion of an igneous mass. Metamorphic changes are caused principally by heat, but also by magma composition and deformation related to the intrusion. Pressures are relatively low (<3000 bars) while temperatures range from 200°C to 1000°C.
What is a Concrete Gravity Dam? A Concrete Gravity Dam is also known as “Gravity Arch Dam,” and is a freshwater-retaining concrete structure that has a wider footing (base) than the top-section. The purpose of a Concrete Gravity Dam is to maintain a low center of gravity, in order to avoid collapsing in the event…
Retaining Wall Retaining Wall: A structure that provides the support needed to hold (in place) a mass of earth, preventing it from moving downhill. Retaining walls are relatively rigid structures comprising footings and a drainage system, in order to retain the soils between two different elevations. Updated May 25, 2020. Construction & Design A lot…
Environmental Geology Environmental Geology: (en·vi·ron·men·tal ge·ol·o·gy) a branch of geology that relates to the impact of human activity on Earth, and the pollution of geologic formations, reserves, and resources. Common focus points of environmental geology are contaminated soil, groundwater aquifers, lakes, rivers, and the ocean. Professional geologists assess and remediate contamination plumes in all media,…
