9.1. This data frame gilgais was collected on a line transect survey in gilgai territory in New South Wales, Australia. Gilgais are natural gentle depressions in otherwise flat land, and sometimes seem to be regularly distributed. The data collection was stimulated by the question: are these patterns reflected in soil properties? At each of 365 sampling locations on a linear grid of 4 metres spacing, sampies were taken at depths 0-10cm, 30-40cm and 80-90cm below the surface.

pH, electrical conductivity and chloride content were measured on a 1:5 soil:water extract from each sampie.

Produce smoothed maps of the measurements.