This is a subset from the US National Geochemical Survey database (NGS), which contains 74,408 samples of 53(+286) attributes sampled over the period from (1979) 2003 to 2008. We focus on the following eight heavy metals: "As", "Cd", "Cr", "Cu", "Ni", "Zn", "As2", "Hg", "Pb". Please consider obtaining the original data directly from the NGS homepage [1].
Formal class 'SpatialPointsDataFrame' [package "sp"] with 5 slots ..@ data :'data.frame': 74408 obs. of 11 variables: .. ..$ AS_ICP40: num [1:74408] 5 5 5 15 5 5 5 5 5 5 ... .. ..$ CD_ICP40: num [1:74408] 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 ... .. ..$ CR_ICP40: num [1:74408] 120 63 160 130 120 120 43 300 100 70 ... .. ..$ CU_ICP40: num [1:74408] 49 32 51 60 45 41 28 94 57 52 ... .. ..$ NI_ICP40: num [1:74408] 60 29 69 93 45 40 22 86 67 45 ... .. ..$ ZN_ICP40: num [1:74408] 110 99 75 85 88 90 98 74 92 120 ... .. ..$ AS_AA : num [1:74408] NA NA NA NA NA NA NA NA NA NA ... .. ..$ HG_AA : num [1:74408] 0.01 0.01 0.01 0.08 0.01 0.01 0.01 0.01 0.08 0.01 ... .. ..$ PB_ICP40: num [1:74408] 11 12 4 2 5 5 11 2 2 5 ... .. ..$ CATEGORY: Factor w/ 6 levels "NURE","NURE SIEVED",..: 3 3 3 3 3 3 3 3 3 3 ... .. ..$ TYPEDESC: Factor w/ 16 levels "BEACH-SED","CANAL-SED",..: 10 10 10 10 10 10 10 10 10 10 ... ..@ coords.nrs : num(0) ..@ coords : num [1:74408, 1:2] -1758399 -1757766 -1757551 -1757346 -1759941 ... .. ..- attr(*, "dimnames")=List of 2 .. .. ..$ : NULL .. .. ..$ : chr [1:2] "coords.x1" "coords.x2" ..@ bbox : num [1:2, 1:2] -10423650 277823 2255815 6536523 .. ..- attr(*, "dimnames")=List of 2 .. .. ..$ : chr [1:2] "coords.x1" "coords.x2" .. .. ..$ : chr [1:2] "min" "max" ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slots .. .. ..@ projargs: chr " +proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=23 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs +towgs84=0,0,"| __truncated__
USGS / The National Geochemical Survey Team
Attachment | Size |
---|---|
NGS8HMC.Rdata [2] | 1.61 MB |
Links:
[1] http://tin.er.usgs.gov/geochem/
[2] http://spatial-analyst.net/book/system/files/NGS8HMC.Rdata
[3] http://spatial-analyst.net/book/node/142