The Haghartsin deposit of ferruginous sandstones (Armenia) is hosted by Middle Eocene sedimentary rocks. A productive horizon is composed of alternating beds of volcanic sandstones and gravelites with magnetite interbeds and massive strata. Five ferruginous sandstone beds with cross-bedding extend for 5.5 km with an average thickness of 2.5 m. The chemical composition of rocks have elevated Fe, Ti, V, Zn, As, and Ge contents relatively to the clarke value and are depleted Rb, Cs, and Ba. Rare earth element contents are close to PAAS standard. The Ybsn/Lasn and Gdsn/Lasn ratios of ferruginous sandstones are 2.2–3.1 and 3.8–4.4, respectively. The δ13C isotope ratio for ferrous carbonate varies from –4.84 to –13.45‰ VPDB. The ferruginous sandstones are products of lithification of beach sediments. The ore-forming detrital Ti-bearing magnetite was likely sourced from the Middle Eocene mafic volcanic rocks. Authigenic ferrous carbonate formed through abiotic oxidation reactions of organic matter, as well as the assimilation of carbonate ions from primary dissolved carbonate.
Keywords. Lesser Caucasus, Armenia, Haghartsin, ferruginous sandstone, Eocene.
Funding. Laboratory studies were supported by state contract of the South Urals Federal Research Center of Mineralogy and Geoecology UB RAS no. 122031600292-6.
Acknowledgements. We are grateful to M.N. Malyarenok, T.V. Semenova and L.G. Udachina for chemical analyses of samples andA.I. Brusnitsyn for meticulous review of the manuscript and valuable comments. The archival materials are available on the website of the Geological Fund of the Republic of Armenia (https://www.geo-fund.am/ru/), to which they would like to express their special gratitude for providing open access.
Conflict of interests. The authors declare that there are no conflicts of interest related to this manuscript.
Author contributions. K. Novoselov – fieldwork, concept development, research, manuscript writing; E. Belogub – analysis, manuscript editing; K. Filippova, M. Rassomakhin, and S. Sadykov – analysis, interpretation of results. All authors approved the final version of the article before publication.
For citation: Novoselov K.A., Belogub E.V., Filippova K.A., Rassomakhin M.A., Sadykov S.A. Magnetite sandstones of the Haghartsin Fe-Ti deposit (Armenia): mineralogical and geochemical features. Mineralogy, 2026, 12(3), 45–65. https://doi.org/10.35597/2313-545X-2026-12-3-3

Received 20.06.2026, revised 29.06.2026, accepted 28.07.2026

Konstantin A. Novoselov – Cand. Sci. (Geol.-Mineral.), Leading Researcher, South Urals Federal Scientific Center of Mineralogy and Geoecology UB RAS, Miass, Russia; const31@yandex.ru
Elena V. Belogub – Doct. Sci. (Geol.-Mineral.), Key Researcher, South Urals Federal Scientific Center of Mineralogy and Geoecology UB RAS, Miass, Russia; belogub@mineralogy.ru
Kseniya A. Filippova – Cand. Sci. (Geol.-Mineral.), Scientific Researcher, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Miass, Russia; kseniyafil@yandex.ru
Mikhail A. Rassomakhin – Junior Researcher, South Urals Federal Scientific Center of Mineralogy and Geoecology UB RAS, Miass, Russia; miha_rassomahin@mail.ru
Sergey A. Sadykov – Cand. Sci. (Geol.-Mineral.), Scientific Researcher, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Miass, Russia; sadykov@mineralogy.ru

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