Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-19T22:56:46.826Z Has data issue: false hasContentIssue false
  • English
  • Français

Metastable Si-Fe phases in hydrothermal sediments of Atlantis II Deep, Red Sea

Published online by Cambridge University Press:  09 July 2018

N. Taitel-Goldman  and
A. Singer
N. Taitel-Goldman*
Affiliation:
The Open University of Israel, P.O. Box 39328 Tel Aviv The Seagram Center for Soil and Water Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, RehovotIsrael
A. Singer
Affiliation:
The Seagram Center for Soil and Water Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, RehovotIsrael
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Amorphous silicate sediments comprise most of the upper part of the sedimentary column of the Atlantis II Deep, whereas more crystalline phases are found in the lower part. The objective of this study was to focus on the newly-formed, metastable, hydrothermal phases, that eventually transform into clays or Fe oxides.

Short-range ordered Si-Fe phases (Si/Fe = 0.2 0.6) rounded to elliptical in shape, and amorphous Si-Fe platy phases (Si/Fe = 0.09 pure Si) comprise some of the amorphous sediments in Atlantis II Deep. The rounded particles have distinct electron-dense (thicker, relatively ordered) margins and a less crystalline inner core. They have rhombohedral symmetry with unit-cell parameters of a= 0.504 nm and c= 1.08 nm. They presumably transform into crystalline clay minerals in statunascendi(at the formative stage) in the sediments. Synthesis in NaCl brines designed to simulate crystallization of the rounded particles, was performed successfully. Similar rounded phases (Si/Fe = 0.26) were synthesized under saline, neutral, hydrothermal conditions (40°C, pH 7, 2 M NaCl) with initial Si/Fe = 1.5. We suggest that the metastable rounded particles precipitate from the hot brine created by the encounter between Red Sea Deep Water and the hydrothermal brine underneath. Within a few thousands years they disintegrate and transform into clay minerals, probably nontronite.

Keywords

amorphousAtlantis II Deephydrothermalshort range orderedSi-Fe phaserounded particles
Type
Research Article
Information
Clay Minerals , Volume 37 , Issue 2 , June 2002 , pp. 235 - 248
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ahn, J.H. & Buseck, P.R. (1990) Hematite nanospheres of possible colloidal origin from a Precambrian banded iron formation. Science, 250, 111–113.CrossRefGoogle ScholarPubMed
Anschutz, P. & Blanc, G. (1995) Geochemical dynamics of the Atlantis II Deep (Red Sea): silica behavior. Marine Geology, 128, 25–36.CrossRefGoogle Scholar
Bäcker, V.H. & Richter, H. (1973) Die rezente hydrothermal- sedimentäre Lagerstätte Atlantis II Tief im Roten Meer. Geologische Rundschau, 62, 697–741.CrossRefGoogle Scholar
Badaut, D., Besson, G., Decarreau, A. & Rautureau, R. (1985) Occurrence of a ferrous, trioctahedral smectite in recent sediments of Atlantis II Deep, Red Sea. Clay Minerals, 20, 389–404.CrossRefGoogle Scholar
Badaut, D., Blanc, G. & Decarreau, A. (1990) Variation des Mineraux argileux ferriferes, en function du temps et de l’espace, dans les depots metaliferes de la fosse Atlantis II en Mer Rouge. Comptes Rendus de l’Académie des Sciences, Paris,Serie II,1069–1075.Google Scholar
Bischoff, J.L. (1972) A ferroan nontronite from the Red Sea geothermal system. Clays and Clay Minerals, 20, 217–223.CrossRefGoogle Scholar
Butuzova, G.Yu. & Lisitsyna, N.A. (1984) Metal deposits in deep subbasins of the Red Sea; ore geochemistry and distribution pattern. Lithology and Mineral Resources of the USSR, 18, 224–238.Google Scholar
Cornell, R.M. & Schwertmann, U. (1996) The Iron Oxides, Structure, Properties, Reactions, Occurrence and Uses. VCH, Weinheim-New York- Basel-Cambridge-Tokyo 573 pp.Google Scholar
Decarreau, A., Bonnin, D., Badaut-Trauth, D., Couty, R. & Kaiser, P. (1987) Synthesis and crystallogenesis of ferric smectite by evolution of Si-Fe coprecipitates in oxidizing conditions. Clay Minerals, 22, 207–223.CrossRefGoogle Scholar
Eggleton, R.A. (1987) Noncrystalline Fe-Si-Al-oxyhydroxides. Clays and Clay Minerals, 35, 29–37.CrossRefGoogle Scholar
Farmer, V.C. (1974) The layer silicates. Pp. 331–363 in. The Infrared Spectra of Minerals (Farmer, V.C., editor). Monograph 4, Mineralogic al Society, London.CrossRefGoogle Scholar
Hartmann, M. (1985) Atlantis II Deep geothermal brine system. Chemical processes between hydrothermal brines and Red Sea deep water. Marine Geology, 64, 157–177.CrossRefGoogle Scholar
Hartmann, M., Scholten, J.C., Stoffers, P. & Wehner, F. (1998) Hydrographic structure of brine filled deeps in the Red Sea new results from Shaban, Kerbit, Atlantis II and Discovery Deep. Marine Geology, 144, 311–330.CrossRefGoogle Scholar
Kawano, M., Tomita, K. & Kamino, Y. (1993) Formation of clay minerals during low temperature experimental alteration of obsidian. Clays and Clay Minerals, 41, 431–441.CrossRefGoogle Scholar
Ryskin, Y.I. (1974) The vibration of protons in minerals: hydroxyl, water and ammonium. Pp. 137–181 in. The Infrared Spectra of Minerals (Farmer, V.C., editor). Monograph 4, Mineralogical Society, London.CrossRefGoogle Scholar
Schwertmann, U., Friedl, J., Stanjek, H., Murad, E. & Bender Koch, C. (1998) Iron oxides and smectites in sediments from the Atlantis II Deep, Red Sea. European Journal of Mineralogy, 10, 953–967.CrossRefGoogle Scholar
Shanks III, W.C. & Bischoff, J.L. (1980) Geochemistry, sulfur isotope composition, and accumulation rates of Red Sea geothermal deposits. Economic Geology, 75, 445–459.CrossRefGoogle Scholar
Singer, A. & Stoffers, P. (1987) Mineralogy of a hydrothermal sequence in a core from the Atlantis II Deep, Red Sea. Clay Minerals, 22, 251–267.CrossRefGoogle Scholar
Singer, A., Stoffers, P., Heller-Kallai, L. & Szafranek, D. (1984) Nontronite in a deep sea core from the South Pacific. Clays and Clay Minerals, 32, 375–383.CrossRefGoogle Scholar
Taitel-Goldman, N. & Singer, A. (2001) High-resolution transmission electron microscopy study of newly formed sediments in the Atlantis II Deep, Red Sea. Clays and Clay Minerals, 49, 174–182.CrossRefGoogle Scholar
Taitel-Goldman, N., Singer, A. & Stoffers, P. (1999) A new short-range ordered, Si-Fe phase in the Atlantis II Deep, Red Sea, hydrothermal sediments. Pp. 697–705 in: Proceedings 11th International Clay Conference, Ottawa, Canada, 1997 (Kodama, H., Mermut, A.R. & Torrance, J.K., editors).Google Scholar
White, W.B. (1974) The carbonate minerals. Pp. 227–284 in. The Infrared Spectra of Minerals (Farmer, V.C.,editor).Monograph 4, Mineralogical Society, London.CrossRefGoogle Scholar