Well Log: A geological well log (or boring log) is a detailed record of subsurface materials encountered during a drilling project. Boring logs, or well logs, are written by a geologist, and describe the physical subsurface characteristics and lithological units encountered during well-plotting. Well logs include information about depth, different formations, and fluid content.
Time Stratigraphic Unit Definition A Time Stratigraphic Unit, or a Chronostratigraphic Unit, is a rock unit that is characterized by geological formations, during a specific period of time. This serves as a reference for all rocks formed during the same time period.
What is a Concrete Slab and Buttress Dam? A Concrete Slab and Buttress Dam is a freshwater-retaining structure comprising reinforced concrete slabs that are supported in-place by buttresses. The foundation of a Concrete Slab and Buttress Dam receives a large load. Thus, the foundation must be structurally sound, impervious, and competent. The alternative types of dams…
Reverse Fault 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…
Volatile Organic Compounds (VOCs) Volatile Organic Compounds (VOCs): Volatile Organic Compounds are toxic organic chemicals with higher tendencies to change from liquid to vapor phase under typical earth pressures and temperatures, and usually have little-to-no water solubility characteristics. VOCs are commonly found within hydrocarbon-based fuel additives, industrial solvents, refrigerants, hydraulic fluids, degreasers, and more. These…
Effective Size (D10) “Effective Size” (D10) is an engineering geology term. Effective Size represents a diameter that directly corresponds to the percentage, by weight, of grains that equal to 10% on the grain-size diagram. To illustrate, 10% of the soil sample particles are finer-grained, and 90% of the sample particles are coarser than the “effective…
Dilatancy “Dilatancy” is the increase in the bulk volume of a soil substance during deformation. Dilatancy is caused by the change from a close-pack structure to an open-pack structure.
