Surface Geology of Australia 1:2.5 million scale dataset 2012 edition

The 1:2.5M scale geology of Australia data documents the distribution and age of major stratigraphic, intrusive and medium to high-grade metamorphic rock units of onshore Australia. This edition contains the same spatial content as the previous edition, but its geological attribute data is more complete than the 2010 edition.
The dataset was compiled to use at scales between 1:2.5 million and 1:5 million inclusive. The units distinguished/mapped mainly represent stratigraphic supergroups, regional intrusive associations and regional metamorphic complexes. Groupings of Precambrian units in the time-space diagram are generally separated by major time breaks; Phanerozoic units are grouped according to stratigraphic age i.e. System/Period. The time-space diagram has the added benefit that it provides a summary of units currently included on the themes. The method used to distinguish sedimentary and many volcanic units varies for each geological eon as follows:
- Cainozoic units are morphological units which emphasise the relationship of the sedimentary fill to the landscape.
- Mesozoic units are regionally extensive to continent-wide time-rock units which emphasise the System of Period(s).
- Paleozoic units are stratotectonic units that emphasise either the dominant System or Period(s) or the range of Periods.
- Proterozoic units are commonly regional stratotectonic units - separated by major time breaks and split into the Paleoproterozoic, Mesoproterozoic and Neoproterozoic Eras - which are generally unique to each cratonic region.
- Archaean units are regional lithological units grouped into broad time divisions.
Metamorphic units are lithological units which emphasise the metamorphic facies and timing of the last major metamorphic event.

澳大利亚1:250万比例尺地质数据集记录了澳大利亚陆上主要地层岩（stratigraphic）、侵入岩（intrusive）及中高级变质岩单元的分布与时代信息。本版数据集的空间内容与前一版一致，但地质属性数据较2010版更为完整。
该数据集编译后适用于1:250万至1:500万（含两端）的比例尺范围。所区分/绘制的单元主要代表地层超群（stratigraphic supergroups）、区域侵入岩组合（regional intrusive associations）及区域变质杂岩（regional metamorphic complexes）。时空图中前寒武纪（Precambrian）单元的分组通常以重大时间间断为界；显生宙（Phanerozoic）单元则依据地层时代（stratigraphic age），即系/纪（System/Period）进行分组。时空图的额外优势在于其提供了当前主题所包含单元的概要信息。
区分沉积岩（sedimentary）和多数火山岩单元的方法因地质宙（geological eon）而异，具体如下：
- 新生代（Cainozoic）单元为形态单元（morphological units），强调沉积充填物与地貌的关系。
- 中生代（Mesozoic）单元为区域延伸至大陆范围的时间-岩石单元（time-rock units），强调系/纪。
- 古生代（Paleozoic）单元为地层构造单元（stratotectonic units），强调主导系/纪或纪的范围。
- 元古宙（Proterozoic单元通常为区域地层构造单元——由重大时间间断分隔，并划分为古元古代（Paleoproterozoic）、中元古代（Mesoproterozoic）和新元古代（Neoproterozoic）——且一般为各克拉通区域所特有。
- 太古宙（Archaean）单元为区域岩性单元（lithological units），按宽泛的时间划分进行分组。
变质岩单元为岩性单元，强调变质相（metamorphic facies）及最后一次重大变质事件的时代。