Hkey	ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚ Term	ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚ Guidance
1	Observed	Feature located on basis of observations at locales that are separated by distances that are insignificant at the scale of mapping
1.1	Observed on ground	"Feature located on basis of visual observations from a distance of less than 10 meters. The observed phenomena may include changes in soil color, vegetation, or slope that are inferred to be a direct result of the mapped feature"
1.2	Observed on ground from a distance	"Feature located on basis of visual observations from a distance of more than 10 meters. The observed phenomena may include changes in soil color, vegetation, or slope that are inferred to be a direct result of the mapped feature"
1.3	Observed in remotely-sensed imagery	"Feature located on basis of observations and interpretation of aerial photographs or other remotely sensed reflectance data, including non-visible wavelengths and possible digital enhancement. The observed phenomena may include changes in soil color, vegetation, or surface character that are inferred to be a direct result of the mapped feature"
1.4	Observed in topographic model	"Feature located on basis of a representation of topography (scale model, digital elevation model, contour map, et cetera).  Includes topography from all sources, including photogrammetry, lidar, IFSAR, plane table, ... "
1.5	Observed in subsurface data	
1.5.1	Observed in excavation	"Feature located on basis of observations made in a trench, pit, or other excavation"
1.5.2	Observed in borehole core	Feature located on basis of observations in core obtained from a borehole.
	Observed in borehole cuttings	Feature located on basis of observation of cuttings obtained from a borehole.
1.5.3	Observed in geophysical log of bore hole	Feature located on basis of measurements made by electronic bore hole logging device(s) that measure geophysical properties.
1.6	Observed by geophysical survey	"Feature located on basis of instrumental measurements of physical properties of in-situ earth materials. Such properties include density, acoustic velocity, magnetic susceptibility, radioactivity, etc."
1.6.1	Observed by seismic survey	Feature located on basis of seismic reflection and (or) seismic refraction survey 
1.6.2	Observed by aeromagnetic survey	Feature located on basis of magnetic field data acquired by airborne sensor.
1.6.3	Observed by gravity survey	Feature located on basis of measured variations in the acceleration of gravity related to mass of underlying Earth material.
1.6.4	Observed by ground magnetic survey	"Feature located on basis of magnetic field data acquired by sensor on the earth surface, either at manually occupied stations, or by a vehicle-based continuously collected sensor data."
1.6.5	Observed by radiometric survey	Feature located on basis of measured flux or intensity of radiation related to the decay of radioactive elements in Earth material. Use for both airborne and ground-surface based sensor.
1.7	Observed by sample analyses	"Feature located on basis of analyses of samples. Analytical method(s) may include staining and point counting, thin-section petrography, chemical analysis, physical analysis (density, magnetization, etc.), geochronological analysis"
2	Inferred	Feature does not have observed manifestation for significant intervals at the scale of observation.
2.1	Inferred by projection from observed locations	Feature located on basis of continuity with observed locations and assumption of continuity of the feature.
2.1.1	Inferred by projection beneath unmapped surficial material	"Feature located on basis of continuity with observed locations and assumption of continuity of the feature. Not observable because of covering mantle of soil, talus, loess, or colluvium that are not mapped as separate geologic units."
2.1.2	Inferred by projection beneath vegetation	"Feature located on basis of continuity with observed locations, and assumption of continuity of the feature. Not observable because of obscuring vegetation, but inferred to crop out at surface."
2.4	Inferred on basis of geological interpretation	"Feature location basis of geologic reasoning from surrounding observations and inferred earth history.  True of many faults, e.g., missing or duplicated stratigraphic section leads to inference of a fault, change in facing direction may lead to inference of a fold. "
3	Concealed beneath covering mapped unit	Feature is covered by mapped younger geologic unit. Location method not otherwise specified.
4	Location method not specified	Locatability is not specified; use for normative descriptions where locatability may take any value
5	Location method not applicable	Use for lines and points that are not located by a mapping process. Location may defined a priori or be arbitrary. Examples include quadrangle boundaries and cross-section lines