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Genesis of the Enkafela Mn deposit: a record of submarine hydrothermal activity in the Afar Depression, Northeast Ethiopia

Genesis of the Enkafela Mn deposit: a record of submarine hydrothermal activity in the Afar... The genesis of the Enkafela Mn deposit and associated processes were investigated using field mapping, mineralogical and geochemical analyses by XRD, ICP-MS/AES and XRF. The geology is constituted by limestone, evaporites/gypsum, conglomerates and basalt. The orebody is hosted in the limestone and has two distinctive manganese layers: a massive bottom and powdery top. Pyrolusite, romanechite and birnessite are the major ore minerals. The geochemical results indicate elevated MnO (av. 70.25 wt-%), Ba (>10,000 ppm), Sr (>10,000 ppm) and depleted Fe2O3 (av. 0.37 wt-%) and other metals. The massive orebody has higher (172.9 ppm) REE content than the powdery ore (7.84 ppm). Chondrite normalised REE plot shows LREE enrichment for both orebodies. The massive manganese layer shows enrichment in Ce and no Eu anomaly. The powdery manganese is depleted in Ce and Eu. The geochemical and mineralogical studies indicate that the manganese mineralisation has dual sources: hydrogenous and hydrothermal sources (for the massive orebody), and hydrothermal (for the powdery). The data suggest that there was active submarine hydrothermal activity in Dallol associated with the regional geodynamic events while the area was inundated by the Red Sea during the Pleistocene. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Applied Earth Science Taylor & Francis

Genesis of the Enkafela Mn deposit: a record of submarine hydrothermal activity in the Afar Depression, Northeast Ethiopia

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Genesis of the Enkafela Mn deposit: a record of submarine hydrothermal activity in the Afar Depression, Northeast Ethiopia

Abstract

The genesis of the Enkafela Mn deposit and associated processes were investigated using field mapping, mineralogical and geochemical analyses by XRD, ICP-MS/AES and XRF. The geology is constituted by limestone, evaporites/gypsum, conglomerates and basalt. The orebody is hosted in the limestone and has two distinctive manganese layers: a massive bottom and powdery top. Pyrolusite, romanechite and birnessite are the major ore minerals. The geochemical results indicate elevated MnO (av....
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Publisher
Taylor & Francis
Copyright
© 2022 Institute of Materials, Minerals and Mining and The AusIMM
ISSN
2572-6838
eISSN
2572-6846
DOI
10.1080/25726838.2022.2035640
Publisher site
See Article on Publisher Site

Abstract

The genesis of the Enkafela Mn deposit and associated processes were investigated using field mapping, mineralogical and geochemical analyses by XRD, ICP-MS/AES and XRF. The geology is constituted by limestone, evaporites/gypsum, conglomerates and basalt. The orebody is hosted in the limestone and has two distinctive manganese layers: a massive bottom and powdery top. Pyrolusite, romanechite and birnessite are the major ore minerals. The geochemical results indicate elevated MnO (av. 70.25 wt-%), Ba (>10,000 ppm), Sr (>10,000 ppm) and depleted Fe2O3 (av. 0.37 wt-%) and other metals. The massive orebody has higher (172.9 ppm) REE content than the powdery ore (7.84 ppm). Chondrite normalised REE plot shows LREE enrichment for both orebodies. The massive manganese layer shows enrichment in Ce and no Eu anomaly. The powdery manganese is depleted in Ce and Eu. The geochemical and mineralogical studies indicate that the manganese mineralisation has dual sources: hydrogenous and hydrothermal sources (for the massive orebody), and hydrothermal (for the powdery). The data suggest that there was active submarine hydrothermal activity in Dallol associated with the regional geodynamic events while the area was inundated by the Red Sea during the Pleistocene.

Journal

Applied Earth Science – Taylor & Francis

Published: Jan 2, 2022

Keywords: Dallol; genesis; hydrogenous; hydrothermal; manganese

References

  • Ocean history from Afar
  • Evolution of the Danakil Depression (Afar Ethiopia) in light of radiometric age determination
  • Surface displacements in the September 2005 Afar rifting event from satellite image matching: asymmetric uplift and faulting
  • Isotope (Sr, Nd, Pb, O) and trace element geochemistry of volcanics from Erta‘Ale range (Ethiopia)
  • Discriminating between different genetic types of marine ferro-manganese crusts and nodules based on rare earth elements and yttrium
  • Tectonics of the Afar Depression: review and synthesis
  • Geochemistry and mineralogy of seafloor hydrothermal and hydrogenetic Mn oxide deposits from the Manus Basin and Bismarck Archipelago region of the southwest Pacific Ocean
  • Iron manganese-barium deposit from the northern Afar rift (Ethiopia)
  • The Red Sea and Gulf of Aden basins
  • Rare earth element geochemistry of ferromanganese crusts from the Hawaiian Archipelago, central Pacific
  • Geochemistry and depositional environment of Mn oxide deposits in the Tokora Belt, Northeastern Hokkaido, Japan
  • Geology of northern Afar (Ethiopia)
  • On causal links between flood basalts and continental breakup
  • Crustal structure and Magmato tectonic processes in an active rift (Asal-Ghoubbet, Afar, East Africa): 2. Insights from the 23-year recording of seismicity since the last rifting event
  • The rare earth elements in seawater
  • Mineralogy and geochemistry of two metamorphosed sedimentary manganese deposits, Sierra Nevada, California, USA
  • A model for the formation of hydrothermal manganese crusts from the Pitcairn Island hotspot
  • Metallogeny of manganese and ferromanganese ores in Baft ophiolitic melange, Kerman, Iran
  • Geochemistry of hydrothermal manganese deposits from the Pitcairn Island hotspot, southeastern Pacific
  • Geochemical characteristics of sedimentary manganese deposit of Guichi, Anhui Province, China
  • Chalcophanite, ZnMn3O7.3H2O: New crystal structure determinations
  • A new discrimination scheme for oceanic ferromanganese deposits using high field strength and rare earth elements
  • First report of geochemical characteristics of the Sangan manganese occurrence, Northeast Khash, Iran
  • Datationpar la methode U/Th des hautsniveauxdecoreaux de la depression de l'Afar
  • Contrasting REE signatures on manganese ores of iron ore group in north Orissa, India
  • Barium geochemistry in sediment pore waters and formation waters of the oceanic crust on the eastern flank of the Juan de Fuca Ridge (ODP Leg 168)
  • Geochemical characteristics of the Eymir (Sorgun-Yozgat) manganese deposit, Turkey
  • Manganese deposits in Turkey: distribution, types and tectonic setting
  • New geochemical and mineralogical constraints on the genesis of the Vani hydrothermal manganese deposit at NW Milos island, Greece: comparison with the Aspro Gialoudi deposit and implications for the formation of the Milos manganese mineralization
  • Formation of Thetis Deep metal rich sediments in the absence of brines, Red Sea
  • A kinematic model for the development of the Afar Depression and its paleogeographic implications
  • Environments and processes of manganese deposition
  • Mineralogical and geochemical studies on manganese deposits at Abu Ghusun Area, South Eastern Desert, Egypt
  • Geology and geochemistry of Middle Eocene Maden complex ferromanganese deposits from the Elazig-Malatya region, eastern Turkey
  • Geochemistry and origin of Mn deposits in the Waziristan ophiolite complex, north Waziristan, Pakistan
  • Manganese and ferromanganese ores from different tectonic settings in the NW Himalayas, Pakistan
  • Geology and mineral potential of Ethiopia: a note on geology and mineral map of Ethiopia
  • Deposition of submarine crusts rich in manganese and iron
  • Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode
  • Pathways of birnessite formation in alkali medium