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.
Poorly Graded Soil Poorly Graded: In the soil classification process of geology, poorly graded soil represents a sedimentary soil sample that only displays one or a few of the numerous other possible grain sizes for that soil classification, in accordance with the Unified Soil Classification System (USCS). For example, a poorly graded sand (SP) may…
Translational Slide Landslide Translational Slide: In the seismology branch of geology, a translational slide is a type of landslide movement that occurs predominantly along a planar surface. Alternatively, this movement can occur along gently undulating surfaces. For instance, the Palona Schist metamorphic bedrock on the eastern embankment of the former St. Francis Dam comprises an…
Strike-Slip Fault or Transform Fault Strike-Slip Fault (Transform Fault): In the field of geology, a strike-slip fault, or a transform fault, is a fault in which movement is parallel to the strike of the fault plane. The opposite of a strike-slip fault is a dip-slip fault. Left-Lateral or Right-Lateral Strike-Slip Fault A transform fault can…
Stratosphere Stratosphere: The stratosphere of a terrestrial planet is the second-lowest member of the atmosphere. On Earth, the stratosphere starts atop the troposphere at approximately 10 kilometers above mean sea level, and terminates roughly 50 kilometers above mean sea level. In fact, geologists understand that the Earth’s ozone layer exists within the stratosphere, which absorbs…
Dip-Slip Fault Dip-Slip Fault: In geology, a dip-slip fault is any fault in which the earth’s movement is parallel with the dip of the fault plane. For example, a normal fault, reverse fault, or listric fault. The opposite of a dip-slip fault is a strike-slip fault.
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)]
