OConnor {GCDkit} | R Documentation |
Assigns data for O'Connor's triangular diagram into Figaro template
(list 'sheet
') and appropriate values into 'x.data
' and 'y.data
'.
OConnorVolc() OConnorPlut()
The O'Connor's triangular diagram is based on combination of Albite, Anorthite and
K-feldspar modal or normative data. While the function 'OConnorPlut
' can
plot either modal or normative diagrams for plutonic rocks, 'OConnorVolc
'
is to be used exclusively with normative data computed from chemical compositions
of volcanic rocks.
In fact, the triangle represents projection of the Quartz - K-feldspar - Albite - Anorthite tetrahedron. All three diagrams are designed for quartz-rich rocks, i.e. those with quartz contents higher than 10 such silica-rich samples, the rock type can be determined purely on the basis of the feldspars' proportions.
As the specific version of the normative calculation is not mentioned in the
original paper by 'O'Connor (1965)', the function 'CIPW
',
designed after 'Hutchison (1974, 1975)' was implemented.
sheet |
list with Figaro Style Sheet data |
x.data, y.data |
An, Ab and Or data (see details) transformed to orthogonal coordinates |
Vojtech Erban, vojtech.erban@geology.cz
O'Connor J T (1965) A classification for Quartz-rich igneous rocks based on feldspar ratios. U.S. Geol. Survey Prof Paper 525-B: B79-B84
Hutchison C S (1974) Laboratory Handbook of Petrographic Techniques. John Wiley & Sons, New York, p. 1-527
Hutchison C S (1975) The norm, its variations, their calculation and relationships. Schweiz Mineral Petrogr Mitt 55: 243-256
classify figaro CIPW plotDiagram
plotDiagram("OConnorVolc", FALSE) classify("OConnorVolc")