I´ve tried to find the original article by Werner, C.D. (1987) without luck. The other one that I´m aware of is the one written by Hayashi et al. (1994) but the TiO2 vs MGO figure is missing!
I´m using GCDKit but there aren´t classification diagrams that would help me.
The complete reference of the Werner article that I´m looking for in case you have it is:
Werner, C.D. (1987) Saxonian granulites: a contribution to the geochemical diagnosis of original rocks in high-metamorphic complexes. Gerlands Beitraege zur Geophysik, 96: 271–290.
Dear Mr. Correa,
know these publications and also there strong and weak points.
There is no "philosopher´s stone" in dicriminating the protolith of metamoprhic rocks.
The results strongly depend on the grade of metamorphism. Low- to very-low grade stages often still allow for an identification of textures and structures which can direct your thoughts towards one or the other parent rock. In high- to very-high grade stages at the brink anatexis the situation becomes more and a question of believe and hope.
For magmatic rocks some discrimination digrams using "so-called" immobile elements like Zr, Ti and Nb may be helpful.
For (meta) sediments you can use the following parameters:
for paragneisses derived from psammo-pelitic rocks the following parameters and ratios are recommended: K/Rb approx. 250, Ti > 0.5 %, enriched in Al, Cr, Ti, Ni, Co (> 10 ppm
for paraamphibolites (marl) the following data are known: low contents of Cr, Ni, Co, V, Ti, enriched in B, Li, Rb, Cs, relative to orthoamphibolite. Sr/Ba < 1, Cr/Ni < 1, Mg-V, Cr-V positively correlated Ti-V, Cr-Cu is negatively correlated up to o.5 % C.
paraultrabasic rocks (evaporitic) are enriched in Be, Ge, B.
ortho-metamorphic rocks often show the following trace element contents:
Orthogneiss: poor in B and Co, Ti below 3 %
Metabasalt: Cr, V > 200 ppm, Ti > 1%, PGE, Zr > 300 ppm,
increasing the metamoprhic grade up to ortho-eclogite:
Co > 40 ppm, V > 200 ppm, Sc > 20, Ti, Ni
While these bulk chemical compositions are often not indicative of their own it may be helpful to take a closer look also at the morphology of rutile, zircon and tourmaline and their trace element contents. The more focused the target during analysis the better the outcome.
They may at least in parts retain some chemical fingerprints which enable the analyst to constrain the origin of the altered rock.
I suggest a combination of the above approaches to be taken in order to be successfull.
With kind regards
H.G.Dill
Dear Sir
I think the links below will benefit you in your search
http://seed-net.org/wp-content/uploads/2015/12/GEOCHEMICAL-CHARACTERISTIC-OF-METAMORPHIC-ROCKS-FROM-SOUTH-SULAWESI-CENTRAL-JAVA-SOUTH-AND-WEST-KALIMANTAN-IN-INDONESIA.pdf
Article Geochemistry of metamorphic rocks of the Kurai block (Gorny Altai)
https://core.ac.uk/download/pdf/51482612.pdf
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2448-167X2016000400397
http://journals.tubitak.gov.tr/earth/issues/yer-06-15-1/yer-15-1-2-0602-4.pdf
Best Regards
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