In geology, the term “type section” refers to a specific stratigraphic unit, that can be compared to other parts of the geologic unit. For a type section, it’s preferred to describe the location where the geologic unit has the maximum thickness, and where the top and bottom units are observable.
Polychlorinated Biphenyl (PCBs) Polychlorinated Biphenyl (PCBs): Polychlorinated Biphenyl (PCBs) are highly toxic human-engineered chlorinated hydrocarbons that have been used around the world as enhancers to hydraulic oil and electrical insulators. PCBs were applied for maintaining low flammability rates, high boiling points, and stronger chemical stability. As of 1979, PCBs have been banned from use in…
Fault Creep Fault Creep: Fault creep means slow ground displacement of a strike-slip fault or dip-slip fault, that usually occurs without accompanying earthquakes. Fault creep can derive from tectonic activity, or be the result of excessive petroleum and groundwater pumping.
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…
Dry Density (ρd) “Dry Density” (ρd) is a value that represents the density of soil when it is completely dry. To illustrate, it equates to (“bulk density” / 1) + “water content.” This is a common geotechnical engineering laboratory procedure. Dry Density Formula Dry Density = [(Bulk Density ÷ 1) + (Water Content)]
U-Shaped Kitchen U-Shaped Kitchen: A U-shaped kitchen, or a horseshoe kitchen, is a general kitchen plan layout with counters, walls, and cabinets that generally form a square-like or rectangular-like shape of the letter “u.” In the State of California (and other states with similar building code standards), U-shaped kitchens must have a minimum of 60-inches…
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.
