Related Experiment Video
Updated: Mar 31, 2026

Atom Probe Tomography Analysis of Exsolved Mineral Phases
Published on: October 25, 2019
Does a Heavy Fe-Isotope Composition of Akilia Quartz-Amphibole-Pyroxene Rocks Necessitate a BIF Origin?
M J Whitehouse1, R Schoenberg2, C M Fedo3
11 Department of Geosciences, Swedish Museum of Natural History , Stockholm, Sweden .
Iron (Fe) isotope data from Akilia Island
Area of Science:
- Geochemistry
- Early Earth geology
- Isotope analysis
Background:
- The Akilia Island quartz-amphibole-pyroxene (qap) gneiss is debated for its origin and age.
- Previous interpretations suggested biogenic activity and chemical sedimentary origins based on carbon isotopes and Fe isotopes.
Purpose of the Study:
- To investigate the origin of the qap gneiss by analyzing new Fe isotope data.
- To reassess the use of Fe isotopes in determining the protolith of the qap gneiss.
Main Methods:
- Analysis of Fe isotope compositions (δ(56)Fe) across various lithologies of the qap gneiss.
- Comparison of Fe isotope data with undisputed ultramafic igneous layers.
Main Results:
- Fe isotope data were analyzed from all lithologic variants of the qap gneiss.
- Ultramafic igneous layers within the qap gneiss indicate introduction of fractionated Fe.
Conclusions:
- Fe isotopes should be interpreted with caution when inferring a banded iron formation (BIF) protolith for the qap gneiss.
- The presence of ultramafic igneous layers complicates the interpretation of Fe isotopes for sedimentary origins.
More Related Videos
11:50Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
10:12Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples
Published on: June 19, 2018
Related Concept Videos
Acid Mine Drainage
Atomic Fluorescence Spectroscopy
Alkali Metals
Table 1: Properties of the alkali metals
Origin of Photosynthesis
Diversity of Protists III
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...