Experimental Geochemical Maps—A Case Study in Cartographic Techniques for Scientific Research

Abstract

A joint experiment is described in which possible methods of representation of geochemical element distributions were examined. Data, consisting of sampling site locations and the concentrations of some thirty elements in active stream sediments in part of Northern Ireland, were written on to magnetic tape in the proposed standard exchange format before being transferred from the AGRG to the EGU. Research indicated that proportional “wind-rose” symbols seemed to be the best compromise solution. Test maps using “wind-rose” symbols produced at varying scales and with different backgrounds by automated means. Evaluation tests were then devised and geochemists and cartographers used as test subjects. The results of these tests were low levels of accuracy in counting and estimating values; in addition, the effects of varying the cartographic parameters, such as map scale, were minimal. Reasons for this are discussed in the text.