The Kago low-sulfidation gold and silver deposit

A peripheral mineralisation to the Nansatsu high-sulfidation system, southern Kyushu, Japan

Thomas Tindell, Koichiro Watanabe, Akira Imai, Ryohei Takahashi, Adrian J. Boyce, Kotaro Yonezu, Anders Schersten, Laurence Page, Takeyuki Ogata

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The Kago deposit is a small deposit located at the southern tip of the Satsuma Peninsula of Southern Kyushu, Japan. It lies proximal to the well-known Nansatsu-type mineralisation province dominated by high-sulfidation type epithermal deposits. The deposit was heavily mined in the 18 th Century, largely for its relatively higher gold compared to that of surrounding and regional deposits. The Kago deposit is a typical low-sulfidation deposit, characterised by adularia-quartz veins, composed of electrum, Ag-tetrahedrite, polybasite, chalcopyrite and pyrite. Based on mine records, the grade ranged from 4.1 to 13.3 g/t Au and 2.6–6.6 g/t Ag. Alteration grades from low to high temperature argillic into a propylitic zone at the extremes of the vein exposures. Carbonate is absent. Fluid inclusion microthermometry reveals a typical temperature range of 220–240 °C with salinity of 0.7–2.6 NaCl eq. wt%. Electrum from high-grade ore ranges from 66 to 69 wt% Au. 40Ar/39Ar age dating of adularia bearing colloform/crustiform and brecciated veins, suggests a mineralisation event from 4.23 to 4.0 Ma. δ18O of veined and silicified quartz ranges from +4.0 to +18.4‰. δ18OH2O of fluids in equilibrium with quartz, in the dominant range of measured fluid inclusion temperatures, ranges from −6.5‰ to −0.2‰. δ34S of pyrite has a narrow range from −1.8 to 2.7‰. The deposit lies at the northern extent of the classic Nansatsu high-sulfidation epithermal area, in which a number of silicified bodies punctuate the region in a roughly semi-circular shape. The Kago deposit lies within the principle mineralisation age range of the high-sulfidation deposits, which range from 5.5 to 3.7 Ma. The structural displacement of the Kago deposit from the Nansatsu mineralisation and the differing host rocks has greatly influenced alteration, ore and rock-water interaction of the ore depositing fluids. Here we seek to establish the relationship that this extended mineral province has between the differing styles of mineralisation.

Original languageEnglish
Pages (from-to)951-966
Number of pages16
JournalOre Geology Reviews
Volume102
DOIs
Publication statusPublished - Nov 1 2018

Fingerprint

Silver deposits
Gold deposits
Quartz
silver
gold
mineralization
Ores
Fluids
adularia
Bearings (structural)
Rocks
fluid inclusion
pyrite
Carbonates
quartz
epithermal deposit
tetrahedrite
ore grade
Gold
Temperature

All Science Journal Classification (ASJC) codes

  • Geology
  • Geochemistry and Petrology
  • Economic Geology

Cite this

The Kago low-sulfidation gold and silver deposit : A peripheral mineralisation to the Nansatsu high-sulfidation system, southern Kyushu, Japan. / Tindell, Thomas; Watanabe, Koichiro; Imai, Akira; Takahashi, Ryohei; Boyce, Adrian J.; Yonezu, Kotaro; Schersten, Anders; Page, Laurence; Ogata, Takeyuki.

In: Ore Geology Reviews, Vol. 102, 01.11.2018, p. 951-966.

Research output: Contribution to journalArticle

Tindell, Thomas ; Watanabe, Koichiro ; Imai, Akira ; Takahashi, Ryohei ; Boyce, Adrian J. ; Yonezu, Kotaro ; Schersten, Anders ; Page, Laurence ; Ogata, Takeyuki. / The Kago low-sulfidation gold and silver deposit : A peripheral mineralisation to the Nansatsu high-sulfidation system, southern Kyushu, Japan. In: Ore Geology Reviews. 2018 ; Vol. 102. pp. 951-966.
@article{9e771efe7fd74daca7fd28cc85074052,
title = "The Kago low-sulfidation gold and silver deposit: A peripheral mineralisation to the Nansatsu high-sulfidation system, southern Kyushu, Japan",
abstract = "The Kago deposit is a small deposit located at the southern tip of the Satsuma Peninsula of Southern Kyushu, Japan. It lies proximal to the well-known Nansatsu-type mineralisation province dominated by high-sulfidation type epithermal deposits. The deposit was heavily mined in the 18 th Century, largely for its relatively higher gold compared to that of surrounding and regional deposits. The Kago deposit is a typical low-sulfidation deposit, characterised by adularia-quartz veins, composed of electrum, Ag-tetrahedrite, polybasite, chalcopyrite and pyrite. Based on mine records, the grade ranged from 4.1 to 13.3 g/t Au and 2.6–6.6 g/t Ag. Alteration grades from low to high temperature argillic into a propylitic zone at the extremes of the vein exposures. Carbonate is absent. Fluid inclusion microthermometry reveals a typical temperature range of 220–240 °C with salinity of 0.7–2.6 NaCl eq. wt{\%}. Electrum from high-grade ore ranges from 66 to 69 wt{\%} Au. 40Ar/39Ar age dating of adularia bearing colloform/crustiform and brecciated veins, suggests a mineralisation event from 4.23 to 4.0 Ma. δ18O of veined and silicified quartz ranges from +4.0 to +18.4‰. δ18OH2O of fluids in equilibrium with quartz, in the dominant range of measured fluid inclusion temperatures, ranges from −6.5‰ to −0.2‰. δ34S of pyrite has a narrow range from −1.8 to 2.7‰. The deposit lies at the northern extent of the classic Nansatsu high-sulfidation epithermal area, in which a number of silicified bodies punctuate the region in a roughly semi-circular shape. The Kago deposit lies within the principle mineralisation age range of the high-sulfidation deposits, which range from 5.5 to 3.7 Ma. The structural displacement of the Kago deposit from the Nansatsu mineralisation and the differing host rocks has greatly influenced alteration, ore and rock-water interaction of the ore depositing fluids. Here we seek to establish the relationship that this extended mineral province has between the differing styles of mineralisation.",
author = "Thomas Tindell and Koichiro Watanabe and Akira Imai and Ryohei Takahashi and Boyce, {Adrian J.} and Kotaro Yonezu and Anders Schersten and Laurence Page and Takeyuki Ogata",
year = "2018",
month = "11",
day = "1",
doi = "10.1016/j.oregeorev.2017.10.027",
language = "English",
volume = "102",
pages = "951--966",
journal = "Ore Geology Reviews",
issn = "0169-1368",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - The Kago low-sulfidation gold and silver deposit

T2 - A peripheral mineralisation to the Nansatsu high-sulfidation system, southern Kyushu, Japan

AU - Tindell, Thomas

AU - Watanabe, Koichiro

AU - Imai, Akira

AU - Takahashi, Ryohei

AU - Boyce, Adrian J.

AU - Yonezu, Kotaro

AU - Schersten, Anders

AU - Page, Laurence

AU - Ogata, Takeyuki

PY - 2018/11/1

Y1 - 2018/11/1

N2 - The Kago deposit is a small deposit located at the southern tip of the Satsuma Peninsula of Southern Kyushu, Japan. It lies proximal to the well-known Nansatsu-type mineralisation province dominated by high-sulfidation type epithermal deposits. The deposit was heavily mined in the 18 th Century, largely for its relatively higher gold compared to that of surrounding and regional deposits. The Kago deposit is a typical low-sulfidation deposit, characterised by adularia-quartz veins, composed of electrum, Ag-tetrahedrite, polybasite, chalcopyrite and pyrite. Based on mine records, the grade ranged from 4.1 to 13.3 g/t Au and 2.6–6.6 g/t Ag. Alteration grades from low to high temperature argillic into a propylitic zone at the extremes of the vein exposures. Carbonate is absent. Fluid inclusion microthermometry reveals a typical temperature range of 220–240 °C with salinity of 0.7–2.6 NaCl eq. wt%. Electrum from high-grade ore ranges from 66 to 69 wt% Au. 40Ar/39Ar age dating of adularia bearing colloform/crustiform and brecciated veins, suggests a mineralisation event from 4.23 to 4.0 Ma. δ18O of veined and silicified quartz ranges from +4.0 to +18.4‰. δ18OH2O of fluids in equilibrium with quartz, in the dominant range of measured fluid inclusion temperatures, ranges from −6.5‰ to −0.2‰. δ34S of pyrite has a narrow range from −1.8 to 2.7‰. The deposit lies at the northern extent of the classic Nansatsu high-sulfidation epithermal area, in which a number of silicified bodies punctuate the region in a roughly semi-circular shape. The Kago deposit lies within the principle mineralisation age range of the high-sulfidation deposits, which range from 5.5 to 3.7 Ma. The structural displacement of the Kago deposit from the Nansatsu mineralisation and the differing host rocks has greatly influenced alteration, ore and rock-water interaction of the ore depositing fluids. Here we seek to establish the relationship that this extended mineral province has between the differing styles of mineralisation.

AB - The Kago deposit is a small deposit located at the southern tip of the Satsuma Peninsula of Southern Kyushu, Japan. It lies proximal to the well-known Nansatsu-type mineralisation province dominated by high-sulfidation type epithermal deposits. The deposit was heavily mined in the 18 th Century, largely for its relatively higher gold compared to that of surrounding and regional deposits. The Kago deposit is a typical low-sulfidation deposit, characterised by adularia-quartz veins, composed of electrum, Ag-tetrahedrite, polybasite, chalcopyrite and pyrite. Based on mine records, the grade ranged from 4.1 to 13.3 g/t Au and 2.6–6.6 g/t Ag. Alteration grades from low to high temperature argillic into a propylitic zone at the extremes of the vein exposures. Carbonate is absent. Fluid inclusion microthermometry reveals a typical temperature range of 220–240 °C with salinity of 0.7–2.6 NaCl eq. wt%. Electrum from high-grade ore ranges from 66 to 69 wt% Au. 40Ar/39Ar age dating of adularia bearing colloform/crustiform and brecciated veins, suggests a mineralisation event from 4.23 to 4.0 Ma. δ18O of veined and silicified quartz ranges from +4.0 to +18.4‰. δ18OH2O of fluids in equilibrium with quartz, in the dominant range of measured fluid inclusion temperatures, ranges from −6.5‰ to −0.2‰. δ34S of pyrite has a narrow range from −1.8 to 2.7‰. The deposit lies at the northern extent of the classic Nansatsu high-sulfidation epithermal area, in which a number of silicified bodies punctuate the region in a roughly semi-circular shape. The Kago deposit lies within the principle mineralisation age range of the high-sulfidation deposits, which range from 5.5 to 3.7 Ma. The structural displacement of the Kago deposit from the Nansatsu mineralisation and the differing host rocks has greatly influenced alteration, ore and rock-water interaction of the ore depositing fluids. Here we seek to establish the relationship that this extended mineral province has between the differing styles of mineralisation.

UR - http://www.scopus.com/inward/record.url?scp=85034964309&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85034964309&partnerID=8YFLogxK

U2 - 10.1016/j.oregeorev.2017.10.027

DO - 10.1016/j.oregeorev.2017.10.027

M3 - Article

VL - 102

SP - 951

EP - 966

JO - Ore Geology Reviews

JF - Ore Geology Reviews

SN - 0169-1368

ER -