Geochemical surveys density

A national-scale geochemical survey of Australia is under way. It applies ultra low sampling density to transported and well-mixed outlet sediments, which are expected to represent the average composition of large catchments. The NGSA will provide the first complete, internally consistent geochemical data layer for Australia and is expected to find applications in energy and mineral resources exploration. 

Sampling sites were selected based on the regional soil survey and a related study in seven sub-areas, each with coverage of several dozen to hundreds of square kilometers and with representative geological setting and geochemical characteristics. Rice and cultivation layer soil at 146 sites were sampled at a density of one site per square kilometer during rice harvest season, October 2006. 

The high density (approximately 1 sample per 3 km2) lake sediment geochemical program at the Ontario Geological Survey takes advantage of the greater than... 

Geochemical patterns are related to choice of map scale, which depends on densities of data. What map scale and data density used mainly depends on the size of the surveyed area and the purpose of the mapping study. 

McConnell, J.W. (1999) Results of Geochemical Mapping Employing High-Density Lake-Sediment and Water Sampling in Central Labrador Report 99-1, Current Research Newfoundland Department of Mines and Energy, Geological Survey, pp. 17-39. 

Figure 1.2 Sampling density (sampling sites per km2) for different scales of geochemical studies according to the new classification scheme after the continent-wide geochemical baseline surveys were started.

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