NORRRM: A Free Software to Calculate the CIPW Norm

Abstract

This work gives an introduction to the R package NORRRM whose main purpose is to calculate the CIPW Norm. Although there are many softwares and spreadsheets available to estimate the standard mineral assemblages in igneous rocks, this package has the following advantages: a) it has the ability to be run on any operating computer systems (BSD, GNU/Linux, Mac OS X®, Windows®); b) an input argument allows choose different procedures to set the Fe-oxidation ratio; c) the options to use whole-rock major as well as minor oxides and trace elements in the computation; d) the output data yields highly consistent results achieving absolute match between the sum of the input weights of oxides recalculated on an anhydrous basis and the sum of the weights of estimated normative minerals and; e) the functions are written in R language and released under terms that guarantee users the freedom to study, adapt, modify, and distribute the software.