In the field of geology, a rock stratigraphic unit, or a lithostratigraphic unit, is a geologic formation that is identifiable by a specific lithology, as well as a consistent stratigraphic position. For example, the Monterey Formation is a rock stratigraphic unit, as it tends to consistently comprise the same gravel and sand types, and consistently makes contact with other geologic formations, as it spans across the entire western portion of California.
Unconfined Aquifer Unconfined Aquifer: In the hydrogeology branch of geology, an unconfined aquifer is an aquifer that has a water table. In fact, an unconfined aquifer can only be the uppermost hydrogeologic unit and is particularly one that has no hydraulic head (or pressure) that is equal to atmospheric pressure. To illustrate, depth to groundwater…
Gravel Blanket in Methane Mitigation A gravel blanket is a 2-inch or 4-inch thick layer of gravel, sand, or approved material that transmits methane soil gas to the horizontal sub-slab perforated pipes and verticle vent riser of a passive methane mitigation system.
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…
Consolidation “Consolidation” in geology refers to the gradual or slow reduction in the volume of a soil sample (representing a larger soil mass), and the increase in density in response to an applied increasing load, or compressive stress.
Listric Fault Listric Fault: In the field of geology, a listric fault refers to a fault with a curved fault plane. Most listric faults comprise a steeply dipping section near the surface. But the fault plane becomes increasingly flat with depth. Listric faults can be normal faults or reverse faults.
Impervious Membrane in Methane Mitigation Impervious Membrane: In accordance with the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, an impervious membrane is a continuous methane gas barrier. It is a crucial part of the methane mitigation process and underlies a building to impede the vapor intrusion of methane soil gas….
