Open File Report 72
Regolith-landform mapping in the Yilgarn Craton, Western Australia:
Towards a standardized approach
Craig, M.A., Anand, R.R., Churchward, H.M., Gozzard, J.R., Smith,
R.E. and Smith, K.
Knowledge of regolith relationships is essential for control of
most forms of geochemical exploration and many forms of geophysical
exploration. This is particularly true for exploration in the Yilgarn
Craton because of the extent of deep lateritic weathering and the
complexities caused by variable degrees of dismantling and modification
of the lateritic weathering profiles. It is important that the principles
and approaches used or being developed for regolith mapping, establishing
regolith stratigraphy, characterising regolith units, interpretation,
and synthesis be understood - firstly by those engaged in development
of the methods and secondly by users. Three major geoscience agencies
(AGSO, CSIRO, and GSWA) are involved in mapping regolith in the
Yilgarn Craton of Western Australia both collaboratively and separately.
Each group has been working at a different scale as a result of
their original charter, national role, or specific client needs.
Each has developed techniques to suit its own purpose. There is
much common ground in the way each group has mapped the regolith
although, until the present initiative, this was not clearly recognised.
There are still differences between the groups because of the scale
of the work they undertake.
Each group is using landform as a surrogate method of defining
variations in regolith types across mapping areas. The mapping methods
are loosely based on CSIRO Land Systems mapping which varied with
toposequence and included catena concepts used by soil scientists.
Landform-based mapping schemes are internationally recognised as
successful approaches to a variety of problems associated with earth
resources. In Australia, AGSO has adapted the techniques to regolith
mapping at a variety of scales. Those agencies mapping regolith
in the Yilgarn have recognised that landform is the common element
in their approach.
Several scientists from AGSO, CSIRO, GSWA, and Curtin University
have been involved in a working party to clarify the individual
mapping processes, classification of materials, and presentation
of data in map and database form. A summary of mapping techniques,
regolith and landform types, and induration categories shows the
common ground. Perceived similarities and differences between working
methods and definitions are defined. Proposals are suggested for
the development of fully integrated mapping methods and for regolith
and landform terminology. The approaches also take into account
the need to maintain differences in order to account for purpose
and scale variations in the work.
Last updated: Thursday, January 06, 2000 11:47 AM