International standards and resources
The British Geological Survey provides information on groundwater terminology.
Australian conventions and resources
Each state and territory uses its own terminology to describe different sediments and rocks; therefore, the Bureau of Meteorology has produced the National Aquifer Framework (NAF) to provide consistent terminology.
See also the section on groundwater on the Geoscience Australia website.
Most groundwater in Earth’s crust is in aquifers. There are 6 main types of aquifers in Australia. Use lower case for aquifer types:
alluvial coastal fractured rock sedimentary basin paleovalley karst
Caution! The International Commission on Stratigraphy recommends paleo- (not palaeo-).
Use initial capitals for formal names of aquifers:
Great Artesian Basin Carpentaria Basin Leederville Aquifer Yarragadee Aquifer
but lower case for informal (generic) and plural references:
The South Australian aquifers Surat, Bowen and Galilee basins
Reminder. Initial capitals are used only for formal names. Informal and collective (plural) references to the same item do not need capitals.
Hydrogeology
Hydrogeology is the study of the distribution and movement of water in soil and rock.
Sediments and rocks with similar hydrogeologic characteristics are grouped and named into hydrogeologic units. The NAF has 3 tiers: geologic units (typically equivalent to geologic formations), hydrogeologic units (1 or more geologic units that have similar hydrogeologic characteristics and behaviour) and hydrogeologic complexes (collections of hydrogeologic units that, when saturated, are considered part of the same aquifer or aquitard).
Use initial capitals for named hydrogeologic units listed in the NAF:
Cowra Formation Munno Para Clay Hindmarsh Clay Wilson Bluff Limestone
but lower case for informal (generic) and plural references.
