Observation Method (Mapped Feature)

mapped feature is located by survey methods

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inertial survey original

compilation original
definition	Mapped feature geometry derived from one or more published or unpublished data sources, involving some interpretation or generalization by the compiler, not an exact digital reproduction of the sources.

direct observation original

Indicates that mapped feature was delineated and a specifier assigned by direct visual observation.

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observed in aerial imagery original
observed in borehole material original
observed in outcrop original

inertial survey original

surveyed original

mapped feature is located by inertial survey methods

inferred original

Indicates that mapped feature is not directly observable, location and specification based on inference from available evidence.

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inferred drill cuttings original
inferred projection between observed locations original
inferred using indirect method original

inferred aeromagnetic survey original

Location and specification inferred based on magnetic field data acquired by airborne sensor.

inferred borehole geophysical log original

Location and specification inferred based on measurements made by electronic bore hole logging device(s) that measure geophysical properties.

inferred drill cuttings original

inferred original

Geologic feature in bore hole inferred based on interpretation of drill cuttings.

inferred gravity data original

Location and specification inferred based on measured variations in the acceleration of gravity related to mass of underlying Earth material.

inferred ground magnetic survey original