Overview
ISO 710-1:1974 - Graphical symbols for use on detailed maps, plans and geological cross-sections (Part 1: General rules of representation) establishes the general rules for depicting rocks and minerals on detailed geological maps, plans and cross-sections. It defines representation principles (ornaments and elementary symbols), layout rules and how to combine symbols to describe rock types, mixed lithologies and fabric (consolidated vs. loose). Specific symbol sets for rock groups are provided in the subsequent parts of ISO 710 (e.g., Part II sedimentary, Part III magmatic; Parts IV and V were in preparation).
Key topics and requirements
- Scope: General rules for representation of rocks and minerals; particular symbols given in other ISO 710 parts.
- Elementary symbols: Symbols should be simple, easily traceable and expressive of rock nature.
- Composition rules: Basic rocks represented by repeating identical elementary symbols; mixed or intermediate rocks by juxtaposing different elementary symbols.
- Arrangement to indicate texture:
- Irregular arrangement = loose form (e.g., unconsolidated sediments).
- Systematic staggered arrangement = consolidated rock.
- Orientation: Rows of ornaments should be aligned either parallel to stratification/joints or to the map margin - the chosen convention must be indicated on the plan.
- Boundaries: Areas of different rock types are separated by a continuous thin line when a clear natural demarcation exists.
- Colour use: Symbols are intended primarily in black and white to facilitate reproduction; colour is permitted only exceptionally (not for rock types normally reserved for stratigraphic colouring) and must be explained in the map key.
- Unambiguous meaning: Symbols must retain their defined meaning regardless of background; new characteristics not covered by the standard require creation of new symbols.
Practical applications
- Standardized cartographic depiction for geological mapping, field plans and cross-sections.
- Creation of consistent map legends, symbol libraries and GIS style sheets for national geological surveys, academic publications, exploration reports and technical presentations.
- Improves clarity and international interoperability of geological maps by reducing symbol ambiguity across countries and languages.
- Geologists and geological cartographers
- National geological surveys and mapping agencies
- Mining, petroleum and engineering geoscientists
- GIS specialists producing geological map layers
- Academic authors and publishers of geological maps
Related standards
- ISO 710 Part II: Representation of sedimentary rocks
- ISO 710 Part III: Representation of magmatic rocks
- (Parts IV and V: metamorphic rocks and minerals were noted as in preparation in the 1974 edition)
Keywords: ISO 710-1, graphical symbols, geological maps, map symbols, geological cross-sections, representation of rocks and minerals, ISO standard.
