Geology and mineralogy of massive sulfide ores from the central Okinawa trough, Japan

Peter Halbach, Bernhard Pracejus, Andreas Marten

Research output: Contribution to journalArticle

157 Citations (Scopus)

Abstract

Massive sulfide ores were collected from active and inactive vents and smokers and from mounds of the hydrothermal Jade field in the central Okinawa trough (Japan), which is a tectonically active intracontinental back-arc basin located in the northwestern Pacific. The Jade field occurs at a site where the tip of a marine graben segment is thought to be influenced by an obliquely striking shear zone. Small faults in the resulting Izena basin present the paths for circulating hydrothermal solutions discharged at the Jade field. The ores forming from these fluids can be chemically characterized by their respective major components as follows: (1) Zn-Pb rich, (2) Ba-Zn-Pb rich, (3) Zn-Cu rich, (4) Fe-rich replacements, and (5) Zn-Pb-rich impregnations of felsic volcanics. Ore types 1, 2, and 4 originate from chimneys, whereas 3 was collected as large slabs from mounds. Some ore samples show high concentrations of Au (up to 24 ppm) and Ag (up to 1.1%). Mineralogically and texturally, the ores show distinctive differences, even if the overall chemistry is comparable (such as that for 1 and 5). Strong similarities, both geochemically and mineralogically, are found between these ore samples and kuroko-type massive sulfide ores. However, the formation of the Jade deposit is as yet incomplete and at an immature stage. This presents the unique opportunity to examine a modern analogue of an ancient deposit.

Original languageEnglish
Pages (from-to)2210-2225
Number of pages16
JournalEconomic Geology
Volume88
Issue number8
DOIs
Publication statusPublished - Dec 1 1993

Fingerprint

Mineralogy
Sulfides
massive sulfide
mineralogy
Geology
geology
troughs
Ores
sulfides
Japan
trough
minerals
Deposits
deposits
chimneys
Chimneys
Vents
vents
ore
basin

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics
  • Economic Geology
  • Geology

Cite this

Geology and mineralogy of massive sulfide ores from the central Okinawa trough, Japan. / Halbach, Peter; Pracejus, Bernhard; Marten, Andreas.

In: Economic Geology, Vol. 88, No. 8, 01.12.1993, p. 2210-2225.

Research output: Contribution to journalArticle

@article{a3c7ca3a65a34f78b5232a736cb6f786,
title = "Geology and mineralogy of massive sulfide ores from the central Okinawa trough, Japan",
abstract = "Massive sulfide ores were collected from active and inactive vents and smokers and from mounds of the hydrothermal Jade field in the central Okinawa trough (Japan), which is a tectonically active intracontinental back-arc basin located in the northwestern Pacific. The Jade field occurs at a site where the tip of a marine graben segment is thought to be influenced by an obliquely striking shear zone. Small faults in the resulting Izena basin present the paths for circulating hydrothermal solutions discharged at the Jade field. The ores forming from these fluids can be chemically characterized by their respective major components as follows: (1) Zn-Pb rich, (2) Ba-Zn-Pb rich, (3) Zn-Cu rich, (4) Fe-rich replacements, and (5) Zn-Pb-rich impregnations of felsic volcanics. Ore types 1, 2, and 4 originate from chimneys, whereas 3 was collected as large slabs from mounds. Some ore samples show high concentrations of Au (up to 24 ppm) and Ag (up to 1.1{\%}). Mineralogically and texturally, the ores show distinctive differences, even if the overall chemistry is comparable (such as that for 1 and 5). Strong similarities, both geochemically and mineralogically, are found between these ore samples and kuroko-type massive sulfide ores. However, the formation of the Jade deposit is as yet incomplete and at an immature stage. This presents the unique opportunity to examine a modern analogue of an ancient deposit.",
author = "Peter Halbach and Bernhard Pracejus and Andreas Marten",
year = "1993",
month = "12",
day = "1",
doi = "10.2113/gsecongeo.88.8.2210",
language = "English",
volume = "88",
pages = "2210--2225",
journal = "Economic Geology",
issn = "0361-0128",
publisher = "Society of Economic Geologists, Inc",
number = "8",

}

TY - JOUR

T1 - Geology and mineralogy of massive sulfide ores from the central Okinawa trough, Japan

AU - Halbach, Peter

AU - Pracejus, Bernhard

AU - Marten, Andreas

PY - 1993/12/1

Y1 - 1993/12/1

N2 - Massive sulfide ores were collected from active and inactive vents and smokers and from mounds of the hydrothermal Jade field in the central Okinawa trough (Japan), which is a tectonically active intracontinental back-arc basin located in the northwestern Pacific. The Jade field occurs at a site where the tip of a marine graben segment is thought to be influenced by an obliquely striking shear zone. Small faults in the resulting Izena basin present the paths for circulating hydrothermal solutions discharged at the Jade field. The ores forming from these fluids can be chemically characterized by their respective major components as follows: (1) Zn-Pb rich, (2) Ba-Zn-Pb rich, (3) Zn-Cu rich, (4) Fe-rich replacements, and (5) Zn-Pb-rich impregnations of felsic volcanics. Ore types 1, 2, and 4 originate from chimneys, whereas 3 was collected as large slabs from mounds. Some ore samples show high concentrations of Au (up to 24 ppm) and Ag (up to 1.1%). Mineralogically and texturally, the ores show distinctive differences, even if the overall chemistry is comparable (such as that for 1 and 5). Strong similarities, both geochemically and mineralogically, are found between these ore samples and kuroko-type massive sulfide ores. However, the formation of the Jade deposit is as yet incomplete and at an immature stage. This presents the unique opportunity to examine a modern analogue of an ancient deposit.

AB - Massive sulfide ores were collected from active and inactive vents and smokers and from mounds of the hydrothermal Jade field in the central Okinawa trough (Japan), which is a tectonically active intracontinental back-arc basin located in the northwestern Pacific. The Jade field occurs at a site where the tip of a marine graben segment is thought to be influenced by an obliquely striking shear zone. Small faults in the resulting Izena basin present the paths for circulating hydrothermal solutions discharged at the Jade field. The ores forming from these fluids can be chemically characterized by their respective major components as follows: (1) Zn-Pb rich, (2) Ba-Zn-Pb rich, (3) Zn-Cu rich, (4) Fe-rich replacements, and (5) Zn-Pb-rich impregnations of felsic volcanics. Ore types 1, 2, and 4 originate from chimneys, whereas 3 was collected as large slabs from mounds. Some ore samples show high concentrations of Au (up to 24 ppm) and Ag (up to 1.1%). Mineralogically and texturally, the ores show distinctive differences, even if the overall chemistry is comparable (such as that for 1 and 5). Strong similarities, both geochemically and mineralogically, are found between these ore samples and kuroko-type massive sulfide ores. However, the formation of the Jade deposit is as yet incomplete and at an immature stage. This presents the unique opportunity to examine a modern analogue of an ancient deposit.

UR - http://www.scopus.com/inward/record.url?scp=2042462886&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=2042462886&partnerID=8YFLogxK

U2 - 10.2113/gsecongeo.88.8.2210

DO - 10.2113/gsecongeo.88.8.2210

M3 - Article

VL - 88

SP - 2210

EP - 2225

JO - Economic Geology

JF - Economic Geology

SN - 0361-0128

IS - 8

ER -