YbN vs. LaN/YbN {GCDkit} | R Documentation |
Assigns data for the YbN
vs. LaN/YbN diagram for adakite/TTG
discrimination into Figaro template (list 'sheet
') and
appropriate values into 'x.data
' and 'y.data
'.
LaYb(ybrep=FALSE)
ybrep |
logical, should be missing Yb values replaced by Y/2.4? |
Diagram proposed by several authors for discriminating between adakitic (or TTG) and "ordinary" calc-alkaline rocks. The version used here is from Martin (1986).
Martin (1999) suggested that Yb (ppm) could be replaced by
Y (ppm)/2.4. Notionally this could help with old data with missing values.
However if Yb is missing La is also likely to be absent (or unreliable), so by default this
replacement is not done; the user can access it by calling the function with ybrep=TRUE
(not available from GUI).
Normalization values are La = 0.33 ppm, Yb = 0.22 ppm (Nakamura 1974).
sheet |
list with Figaro Style Sheet data |
x.data |
LaN/YbN or La/(Y/2.4) |
y.data |
YbN |
Jean-François Moyen, jfmoyen@gmail.com
Martin H (1986) Effect of steeper Archean geothermal gradient on geochemistry of subduction-zone magmas. Geology 14: 753-756 doi: 10.1130/0091-7613(1986)14<753:EOSAGG>2.0.CO;2
Martin H (1999) Adakitic magmas: modern analogues of Archaean granitoids. Lithos 46: 411-429 doi: 10.1016/S0024-4937(98)00076-0
Nakamura N (1974) Determination of REE, Ba, Fe, Mg, Na and K in carbonaceous and ordinary chondrites. Geochim Cosmochim Acta 38: 757-775 doi: 10.1016/0016-7037(74)90149-5
data(sazava) accessVar("sazava") # plot the diagram plotDiagram("LaYb",FALSE)