gemas: GEMAS geochemical data set
In robCompositions: Compositional Data Analysis

gemas

R Documentation

GEMAS geochemical data set

Description

Geochemical data set on agricultural and grazing land soil

Usage

data(gemas)

Format

A data frame with 2108 observations and 30 variables

Details

COUNTRY: country name
longitude: longitude in WGS84
latitude: latitude in WGS84
Xcoord: UTM zone east
Ycoord: UTM zone north
MeanTemp: Annual mean temperature
AnnPrec: Annual mean precipitation
soilclass: soil class
sand: sand
silt: silt
clay: clay
Al: Concentration of aluminum (in mg/kg)
Ba: Concentration of barium (in mg/kg)
Ca: Concentration of calzium (in mg/kg)

Cr: Concentration of chromium (in mg/kg)
Fe: Concentration of iron (in mg/kg)
K: Concentration of pottasium (in mg/kg)
Mg: Concentration of magnesium (in mg/kg)
Mn: Concentration of manganese (in mg/kg)
Na: Concentration of sodium (in mg/kg)
Nb: Concentration of niobium (in mg/kg)
Ni: Concentration of nickel (in mg/kg)
P: Concentration of phosphorus (in mg/kg)
Si: Concentration of silicium (in mg/kg)
Sr: Concentration of strontium (in mg/kg)
Ti: Concentration of titanium (in mg/kg)
V: Concentration of vanadium (in mg/kg)

Y: Concentration of yttrium (in mg/kg)
Zn: Concentration of zinc (in mg/kg)
Zr: Concentration of zirconium (in mg/kg)
LOI: Loss on ignition (in wt-percent)

The sampling, at a density of 1 site/2500 sq. km, was completed at the beginning of 2009 by collecting 2211 samples of agricultural soil (Ap-horizon, 0-20 cm, regularly ploughed fields), and 2118 samples from land under permanent grass cover (grazing land soil, 0-10 cm), according to an agreed field protocol. All GEMAS project samples were shipped to Slovakia for sample preparation, where they were air dried, sieved to <2 mm using a nylon screen, homogenised and split to subsamples for analysis. They were analysed for a large number of chemical elements. In this sample, the main elements by X-ray fluorescence are included as well as the composition on sand, silt, clay.

Author(s)

GEMAS is a cooperation project between the EuroGeoSurveys Geochemistry Expert Group and Eurometaux. Integration in R, Peter Filzmoser and Matthias Templ.

References

Reimann, C., Birke, M., Demetriades, A., Filzmoser, P. and O'Connor, P. (Editors), 2014. Chemistry of Europe's agricultural soils - Part A: Methodology and interpretation of the GEMAS data set. Geologisches Jahrbuch (Reihe B 102), Schweizerbarth, Hannover, 528 pp. + DVD Reimann, C., Birke, M., Demetriades, A., Filzmoser, P. & O'Connor, P. (Editors), 2014. Chemistry of Europe's agricultural soils - Part B: General background information and further analysis of the GEMAS data set. Geologisches Jahrbuch (Reihe B 103), Schweizerbarth, Hannover, 352 pp.

Examples


data(gemas)
str(gemas)
## sample sites
## Not run: 
require(ggmap)
map <- get_map("europe", source = "stamen", maptype = "watercolor", zoom=4)
ggmap(map) + geom_point(aes(x=longitude, y=latitude), data=gemas)
map <- get_map("europe", zoom=4)
ggmap(map) + geom_point(aes(x=longitude, y=latitude), data=gemas, size=0.8)

## End(Not run)

robCompositions documentation built on Aug. 22, 2025, 5:11 p.m.