| srnd {GCDkit} | R Documentation | 
Age-corrects the Sr-Nd isotopic data to a given age; calculates initial ε(Nd) values and Nd model ages.
    srnd(age = NULL)
    initial(age = NULL, x = WR, system = "Nd")
    epsilon(age, x = WR)
    DMage(x = WR)
    DMGage(x = WR)
    DMLHage(age = NULL, x = WR, RCC = 0.12)
| age | age in Ma. | 
| x | numeric matrix with isotopic data to be recalculated. | 
| system | character; which isotopic system: Sr or Nd? | 
| RCC | numeric; the 147Sm/144Nd ratio of the intermediate crustal reservoir for calculation of the two-stage Nd model ages. | 
Recalculates the Sr-Nd isotopic data and returns them in the numeric matrix 
init with the following columns (DM = Depleted Mantle):
| Age (Ma) | Age in Ma | 
| 87Sr/86Sri | Initial 87Sr/86Sr ratios | 
| 143Nd/144Ndi | Initial 143Nd/144Nd ratios | 
| EpsNdi | Initial ε(Nd) values | 
| TDM | Single-stage DM Nd model ages (Liew & Hofmann, 1988), function DMage | 
| TDM.Gold | Single-stage DM Nd model ages (Goldstein et al., 1988), function DMGage | 
| TDM.2stg | Two-stage DM Nd model ages (Liew & Hofmann, 1988), function DMLHage | 
If the parameter age in call to the main function srnd() is empty, 
and no column named Age is found in the dataset, 
the user is prompted to enter a value. 
For other functions, the argument age is empty, it is taken from the 
value assigned upon loading the dataset. 
For srnd():
| init | numeric matrix with the results | 
| age | numeric vector with the ages used in calculations for each sample | 
For all functions:
| results | numeric matrix, or vector, with the results | 
SrNd.r
Vojtěch Janoušek, vojtech.janousek@geology.cz
Goldstein SL, O'Nions RK & Hamilton PJ (1984) A Sm-Nd isotopic study of atmospheric dusts and particulates from major river systems. Earth Planet Sci Lett 70: 221-236 doi: 10.1016/0012-821X(84)90007-4
Liew TC & Hofmann AW (1988) Precambrian crustal components, plutonic associations, plate environment of the Hercynian Fold Belt of Central Europe: indications from a Nd and Sr isotopic study. Contrib Mineral Petrol 98: 129-138 doi: 10.1007/BF00402106
elemIso, reciprocalIso, ageEps,
    sampleDataset("blatna_iso")
    
    srnd() # Using the age information from the file; 
    # This is done automatically upon loading a new data file.
    
    srnd(500)
    
    initial(346,system="Sr")
    out<-cbind(epsilon(0),epsilon(346))
    colnames(out)<-c(0,346)
    print(out)
    
    DMage()
    DMGage()
    DMLHage()