Version 1
: Received: 17 October 2024 / Approved: 17 October 2024 / Online: 18 October 2024 (16:34:15 CEST)
How to cite:
Peretyazhko, I. S.; Savina, E. A. Formation Conditions of Extremely Reduced High-Temperature Mineral Assemblages in Rocks of Combustion Metamorphic Complexes (Mongolia). Preprints2024, 2024101443. https://doi.org/10.20944/preprints202410.1443.v1
Peretyazhko, I. S.; Savina, E. A. Formation Conditions of Extremely Reduced High-Temperature Mineral Assemblages in Rocks of Combustion Metamorphic Complexes (Mongolia). Preprints 2024, 2024101443. https://doi.org/10.20944/preprints202410.1443.v1
Peretyazhko, I. S.; Savina, E. A. Formation Conditions of Extremely Reduced High-Temperature Mineral Assemblages in Rocks of Combustion Metamorphic Complexes (Mongolia). Preprints2024, 2024101443. https://doi.org/10.20944/preprints202410.1443.v1
APA Style
Peretyazhko, I. S., & Savina, E. A. (2024). Formation Conditions of Extremely Reduced High-Temperature Mineral Assemblages in Rocks of Combustion Metamorphic Complexes (Mongolia). Preprints. https://doi.org/10.20944/preprints202410.1443.v1
Chicago/Turabian Style
Peretyazhko, I. S. and Elena A. Savina. 2024 "Formation Conditions of Extremely Reduced High-Temperature Mineral Assemblages in Rocks of Combustion Metamorphic Complexes (Mongolia)" Preprints. https://doi.org/10.20944/preprints202410.1443.v1
Abstract
New data, including Raman spectroscopy, characterize unusual mineral assemblages from rocks of the Naylga and Khamaryn–Khyral–Khiid combustion metamorphic complexes in Mongolia. Several samples of melilite–nepheline paralava and other thermally altered (metamorphosed) sedimentary rocks contain troilite (FeS), metallic iron (Fe0), kamacite (Ni-bearing Fe0), taenite (Ni-rich Fe0), barringerite or allobogdanite (Fe2P), schreibersite (Fe3P), steadite (Fe4P = eutectic α-Fe+Fe3P), wüstite (FeO), and cohenite (Fe3C). The paralava matrix includes a fragment composed of magnesiowüstite–ferropericlase (FeO–MgO solid solution), as well as of spinel (Mg,Fe)Al2O4 and forsterite. The highest-temperature mineral assemblage belongs to a xenolithic remnant, possibly Fe-rich sinter: molten ash left after underground combustion of coal seams. The crystallization temperatures of the observed iron phases were estimated using phase diagrams for the respective systems: Fe–S for iron sulfides and Fe–P for iron phosphides. Iron monosulfide (high-temperature pyrrhotite) with inclusions of Fe0 underwent solid-state conversion into troilite at 140 °C. Iron phosphides in inclusions from the early growth zone of anorthite–bytownite in melilite–nepheline paralava crystallized from < 1370 to 1165 °C (Fe2P), 1165–1048 °C (Fe3P), and
Keywords
reduced mineral assemblages; troilite; iron phosphide; metallic iron; wüstite; magnesiowüstite–ferropericlase; Raman spectroscopy; combustion metamorphic complex; Mongolia
Subject
Environmental and Earth Sciences, Geochemistry and Petrology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
