Geologic Field Mapper

Offline | Stations | Contacts | Faults

Geologic Field Mapper

Digitize stations (points), contacts/faults (lines). Data stays on-device. Export GeoJSON/JSON. Basemaps include USGS Topo and USGS Imagery.

Entry panel

0) Active Feature

Active ID

Active kind

None Draw a feature, or Use GPS to create a station point.

Tip: Tap Use GPS to automatically add a station point at your location. Click features to activate them, then edit attributes and press Update.

Map

Basemaps: USGS, OSM, Carto, Esri, OpenTopo, Stadia. Draw with Leaflet.Draw.

Offline Tiles

Caches basemap tiles (for the selected basemap) into Cache Storage for offline work. Keep extents small.

Basemap to cache

Zoom min

Zoom max

Auto-cache viewed

Idle —

GeoTIFF Overlay

Choose a local .tif/.tiff. It will render as an overlay and fit to bounds.

Choose GeoTIFF

Overlay opacity

Ready —

Plots (Stereonet + Rose)

Stereonet (equal-area)

From station points (filtered by search).

Rose diagram

Azimuth histogram (strike preferred, else trend).

ESRI Layer by Item ID

Load a public ArcGIS Online / Enterprise hosted layer by its item ID.

Portal base URL

Item ID

Layer index

Output style

Ready —

1) Station / Point

GPS

Date

Time

Project / Area

Mapper

Station ID

Traverse ID

Datum

GPS accuracy (m)

Latitude

Longitude

Elevation (optional)

UTM / Grid (optional)

Lithology / rock type

Alteration style

Alt intensity

Mineralization style

Stratigraphy & Contacts (station-level)

Unit name / Formation

Contact type / relationship

Bedding thickness class

Strat notes

Hydrothermal & Alteration (the “Mining” layer)

Vein density (veins / m)

Alteration assemblage

Spectral scan (NIR/SWIR)

Location description

General notes

Station photo

Take or upload a single photo for the station (stored with the station).

Photo file

Photo ID (optional)

Direction (azimuth °)

Tags

Caption

Photo notes

Interpretation

Preview:

Ready —

2) Structural Mapping

Structural feature type

Confidence

Quality notes

Measurement ID

Planes: Strike/Dip (RHR recommended). Lines: Trend/Plunge.

Strike (°)

Dip (°)

Dip direction (°)

Notes (plane)

Trend (°)

Plunge (°)

Lineation type / origin

Notes (line)

Kinematics

Structure notes

Structural photo

Take/upload a single photo for the structural measurement.

Photo file

Photo notes

Same actions as Station buttons (apply to active feature).

3) Contacts & Faults

Applies to mapped line features. Common attributes appear for all lines. Contact-only fields appear for Contact features, and fault-only fields appear for Fault features.

1) Common line attributes

Line name / ID

Line notes

Certainty

Style

Strike (boundary, °)

Dip (boundary, °)

Thickness / width of boundary zone

Locational accuracy

Units across boundary

Left-side unit

Right-side unit

Left-side unit age / code

Right-side unit age / code

2) Contact attributes

Boundary relationship / contact type

Boundary sharpness / character

Cross-cutting

Topographic expression

Vegetation / soil change

Evidence (field cues)

Alteration halo

Transect notes

Vectoring

Spectral scan ID(s)

3) Fault attributes

Fault type

Slip sense

Slip indicator

Estimated offset

Fault rock / zone type

Damage zone width

Core zone width

Slickenline trend / plunge

Kinematic evidence

Fault notes

4) Map Sheet / Quadrangle Packager

Capture the current view as a “sheet” (bounds + basemap + zoom range) and export/import the sheet JSON.

Sheet name

Basemap

Zoom min

Zoom max

Notes

Bounds (auto)

Ready —

Click a row to activate (loads its attributes into the entry panel and zooms to it).

Feature ID	Kind	Lat/Lon	Rock/Alt/Min	Structures	Line attrs	Notes

Tip: Export GeoJSON for QGIS. Cache tiles for offline base maps.