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,
data(blatna_iso) accessVar("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()