'data.frame': 1191 obs. of 12 variables:
$ LABNR : Factor w/ 1173 levels "","AA-78447",..: 2 3 4 5 6 7 8 9 10 11 ...
$ C14AGE : int 2362 2171 834 2310 540 2210 1900 2110 2390 1240 ...
$ C14STD : int 39 37 35 60 50 100 50 60 65 120 ...
$ C13 : num 0 0 0 0 0 0 0 0 0 0 ...
$ MATERIAL : Factor w/ 14 levels "","Animal Bone",..: 1 1 1 5 1 5 1 1 1 1 ...
$ SITE : Factor w/ 471 levels "725","85/22",..: 267 267 267 308 307 185 401 221 390 438 ...
$ COUNTRY : Factor w/ 12 levels "","AGO","BDI",..: 4 4 4 8 7 8 8 7 8 6 ...
$ FEATURE : Factor w/ 102 levels "","ABM 06/1",..: 1 1 1 1 1 1 1 1 1 1 ...
$ FEATURE_DESC: Factor w/ 10 levels "","Burial","Deposit",..: 8 8 8 1 1 1 1 1 1 1 ...
$ LAT : num 3.99 3.99 3.99 NA -4.19 ...
$ LONG : num 16.9 16.9 16.9 NA 15.2 ...
$ SOURCE : Factor w/ 120 levels "Asombang","Asombang 1988",..: 57 57 57 9 104 9 9 30 91 14 ...