Agrawal {GCDkit} | R Documentation |
Plots data stored in 'WR
' into discrimination plots proposed by
Agrawal et al. (2008) for (ultra-) basic rocks (SiO2 < 52 wt. %).
Agrawal(plot.txt = getOption("gcd.plot.text"))
plot.txt |
logical, annotate fields by their names? |
Suite of five diagrams for discrimination of geotectonic environment of ultrabasic and basic rocks, proposed by Agrawal et al. (2008). It is based on linear discriminant analysis applied to log-transformed concentration ratios of five trace elements (La, Sm, Yb, Nb, and Th), i.e., using four ratios ln(La/Th), ln(Sm/Th), ln(Yb/Th), and ln(Nb/Th). The two discriminant functions, DF1 and DF2, are mathematically designed to maximize the separation between the groups and account for 100 percent of the variance in the data.
Note that only samples with SiO2 < 52 wt. % are plotted.
Also note that each diagram applies only to environments explicitly mentioned. Samples from the environment not taken into account will be misinterpreted (the CRB + OIB + MORB diagram is not designed for IAB etc.) See the Agrawal et al (2008) for further details.
Following geotectonic settings may be deduced:
Abbreviation used | Environment |
IAB | island arc basic rocks |
CRB | continental rift basic rocks |
OIB | ocean-island basic rocks |
MORB | mid-ocean ridge basic rocks |
None.
This function uses the plates concept. The individual plots can be selected and their
properties/appearance changed as if they were stand alone Figaro-compatible plots.
See Plate
, Plate editing
and
figaro
for details.
Vojtech Janousek, vojtech.janousek@geology.cz
Agrawal S, Guevara M, Verma S (2008) Tectonic discrimination of basic and ultrabasic volcanic rocks through log-transformed ratios of immobile trace elements. Int Geol Review 50: 1057-1079 doi: 10.2747/0020-6814.50.12.1057
Verma, Plate, Plate editing, plotPlate, figaro
#plot the diagrams plotPlate("Agrawal")