GeoMap guide

A simplified, mobile-friendly version of DMPE's GeoView-WA. It shows regional geology and geophysics to help with groundwater and salinity assessment.

Using the map

• Use the sliders to fade each data layer in or out.
• Tick the boxes to show structures and dykes, or switch to a black and white basemap.
• Top right: centre on your location, and zoom with +/- or pinch.
• Tap the map to see coordinates and share a link to that spot.

Radiometrics (top ~30 cm of soil)

Colours mix potassium (K), uranium (U) and thorium (Th). In the Wheatbelt:

• Black or dark blue: deeper sands (or water), often sandplain.
• Red: potassium-rich valley clays. Pink: shallow soils near bedrock.
• Teal or aqua-green: thorium-rich, gravelly duplex soils over deep weathered regolith.

Geomagnetics (bedrock at depth)

Available as standard colour and 1VD (first vertical derivative, sharper detail).

• Red: high magnetite, likely mafic rock (greenstones, dykes).
• Blue, purple or black: low magnetite (granites, quartz-rich rocks).
• Straight lines: usually dolerite dykes. Weaker linear trends are often faults or shear zones.

Mapped dykes and structures are interpreted by geologists from regional data, and only some are mapped. These features can control groundwater flow and the location of saline discharge. Sandy areas often mean higher recharge.

Limitations

Data comes from regional airborne surveys (line spacing up to 200 m), so accuracy varies by area. It does not show depth to watertable, salinity or bore yield. For drilling data, use the DPIRD Groundwater and Salinity app or the DWER Water Information Reporting tool. Use GeoMap as a guide only. Site decisions need professional advice and ground-based assessment.