feldspar: Ternary feldspar experiments and thermodynamic models

feldsparR Documentation

Ternary feldspar experiments and thermodynamic models

Description

A data set that has been manually transcribed from Table 5 of Elkins and Grove's Ternary feldspar experiments and thermodynamic models.

Usage

feldspar

Format

A data frame of 40 rows and 7 columns:

Experiment

The ID of the experiment

Feldspar

Coexisting feldspars, Alkali or Plagioclase

Or

Proportion of orthoclase

An

Proportion of anorthite

Ab

Proportion of albite

Temperature

Temperature of the reaction (degrees centigrade)

Pressure

Pressure of the reaction (bars)

Abstract

This paper reports the results of 20 experiments in which mixes of two or three feldspars were reacted to produce coexisting plagioclase feldspar (PF) and alkali feldspar (AF). Starting materials with similar bulk compositions were prepared using different combinations of two and three minerals, and experiments were designed to produce similar AF and PF minerals in the experimental products from different starting binary and ternary compositions. The coexisting AF and PF compositions produced as products define compositional fields that are elongate parallel to the ternary solvus. In 11 experiments reaction was sufficient to product fields of coexisting AF and PF, or AF, PF, and melt with a bulk composition close to that of the starting mixture. In six experiments significant reaction occurred in the form of reaction rim overgrowths on seeds of the starting materials. Three experiments produced AF, PF, and melt from a natural granite starting material. A two-feldspar thermometer is presented in which temperature is constrained by equilibria among all three components - Albite, Orthoclase, and Anorthite - in coexisting ternary feldspars.

Source

Elkins LT, Grove TL. Ternary feldspar experiments and thermodynamic models. American Mineralogist. 1990;75(5-6):544-59.


tactile documentation built on May 31, 2023, 9:47 p.m.