Template:LRA 3

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Each geochemical map was prepared by interpolating the point data using the parent material mapping method (Appleton et al., 2013[1]). The LRA area was subdivided into 200 x 200 m squares and intercepted with the geology (parent material) polygons, thereby creating the basic 200 m-PM polygons. For each 200 m-PM polygon the average concentration based on the four nearest samples over the same PM was computed (see further explanation in Materials and methods and references therein). As the maps (produced in ArcGIS 10.1) show estimated concentrations, there is a degree of uncertainty due to variability in soil composition. The element concentration colour ramp is based on percentile classes of the LRD dataset distribution. The tables and graphs were generated running R (R x 64 3.1.0) in RStudio (Version 0.98.977). The LRD, LOND and SEEN surveys are represented by the colours black/white, dark green and dark red respectively. Quaternary, Palaeogene and Cretaceous geological time periods are represented by soft yellow, orange and lime green colours respectively. For further information go to Univariate statistics and graphics

  1. Appleton, J D, Johnson, C C, Ander, E L, and Flight, D M A. 2013. Geogenic signatures detectable in topsoils of urban and rural domains in the London region, UK, using parent material classified data. Applied Geochemistry, Vol. 39, 169–180. DOI 10.1016/j.apgeochem.2013.07.010