USGS



The Venus Geologic Mappers' Handbook




Appendix B: Samples of Geologic Map Symbols




[Notes in brackets]

Contact--Long dashed where approximately located; short dashed where indefinite, gradational, or inferred; dotted where concealed; queried where doubtful

Fault or graben--Long dashed where approximately located; short dashed where inferred or probable; dotted where concealed [must be concealed by overlying mapped deposits]; bar and ball on downthrown side

Fault--Arrows show relative horizontal movement

Thrust fault--Sawteeth on upper plate; dashed where approximately located; intermittent dashed where inferred; dotted where concealed

Fault or lineament--Origin uncertain

Tectonic lineament [Used on small-scale tectonic maps]

Joint [Assumed to be vertical]

Ridge crest

Trough

Depression [Includes large volcanic craters]

Scarp--Barb points downslope, line at base

Flow scarp--Hachures on downslope side

Channel

Crater rim crest--Dotted where buried

Small shield [Less than 20 km across]

Large shield [More than 20 km across]


Mappers' Handbook
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Planetary Geologic Mapping
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