You can use CIA indices for alteration for metapelites.

Can you please recommend me a publication with a similar case if you read any ?

Thanks Dr Azimuddin Mirza

Ahmed Morad Thanks .

Actually Metapelites are mostly enriched in alumina and it is considered like Chemical Index of Alteration for metapelites is approx. 75. reveals moderately weathered protholith.

For more information go through the paper :

Geochemistry of Hindoli Group Metasediments, SE Aravalli Craton NW India: Implications for Paleoweathering and Provenance

Hopefully you will get some idea.

For Metapelites, you can use CIA

TITLE: THE LATE MIOCENE PELITIC SILTSTONE OF THE ISHIM FORMATION (SOUTHWESTERN SIBERIA): MINERALOGICAL AND GEOCHEMICAL CHARACTERIZATION AND PROSPECTS FOR FURTHER USE

Authors: Alexander O. Konstantinov, Pavel V. Smirnov *, Olga B. Kuzmina, Irina V. Khazina, Georgii A. Batalin and Bulat I. Gareev

Informations: Acta Geodyn. Geomater., Vol. 15, No. 3 (191), 259–275, 2018 DOI: 10.13168/AGG.2018.0019 regards

Dear Mr. Morad,

Unless you have carried out a geological survey and studied the mineralogical association of your rocks the chemical studies and the use of any index based upon chemical data is meaningless. It is a repetive critics of mine.

It is good for riding the “paper-tiger” but in practice these figures are of no use. Because what it is all about, is the futile attempt to circumnavigate experience and knowledge in geology and mineralogy. To gather experience needs time and to pile up knowledge even more in combination with a series of physical and mental endowments.

We cannot delegate geosciences to the technicians in the chemical lab.

Sorry for this harsh critics which is a general statement rather a reference to your question.

Sincerely yours

Harald G. Dill