2020年10月
Formation of highly Zn-enriched sulfide scale at a deep-sea artificial hydrothermal vent, Iheya-North Knoll, Okinawa Trough
Mineralium Deposita
- 巻
- 56
- 号
- 5
- 開始ページ
- 975
- 終了ページ
- 990
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1007/s00126-020-01022-3
- 出版者・発行元
- Springer Science and Business Media LLC
Artificial hydrothermal vents, created by boreholes that discharge hydrothermal fluids and useful for observing secular changes in mineral precipitates and the chemical compositions of hydrothermal fluids, are periodically cleaned of scale deposits. Here, we report petrographic and geochemical features of hydrothermal scale with a concentric structure and extreme enrichment in Zn, recovered as an intact plug from an artificial hydrothermal vent pipe in the Okinawa Trough. The scale consists of sphalerite with accessory galena and chalcopyrite, and minor cotunnite (PbCl2), barite, an unidentified Zn sulfate, and Bi-rich minerals. It comprises at least five concentric layers alternating between thin, reddish-brown porous layers composed of relatively Fe-rich sphalerite accompanied by galena and chalcopyrite, and coarse-grained, dark gray layers dominated by relatively Fe-poor sphalerite. Cotunnite occurs only in the innermost reddish-brown layer, and barite occurs only in the uppermost and innermost layers. The scale is composed of > 50 wt% Zn, several wt% Fe and Pb, and < 1 wt% Cu, Mn, and Cd, a composition consistent with the solubility of Zn and Cu in a hydrothermal fluid at 304–311 °C and pH 4.7–5.0. We suggest that the concentric layers are related to periodic scale removal operations through which (1) mostly clogged pipe conditions and weak hydrothermal discharge alternate with (2) fully open pipe conditions and vigorous hydrothermal discharge, thus affecting sulfur fugacity and [Cl−] and [SO42−] activities in the hydrothermal fluid and leading to the formation of concentric layers of precipitated minerals.
- リンク情報
-
- DOI
- https://doi.org/10.1007/s00126-020-01022-3
- URL
- http://link.springer.com/content/pdf/10.1007/s00126-020-01022-3.pdf
- URL
- http://link.springer.com/article/10.1007/s00126-020-01022-3/fulltext.html
- Scopus
- https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85094181308&origin=inward
- Scopus Citedby
- https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85094181308&origin=inward
- ID情報
-
- DOI : 10.1007/s00126-020-01022-3
- ISSN : 0026-4598
- eISSN : 1432-1866
- SCOPUS ID : 85094181308