EPITHERMAL GOLD MINERALIZATION AND MODERN … · ii GUIDEBOOK SERIES of the SOCIETY OF ECONOMIC GEOLOGISTS SERIES EDITOR: Tommy B. Thompson Graphic Design/Printing by Johnson Printing

Guidebook Prepared for the Society of Economic Geologists Field Trip 28 October-3 November 2001

Series Editor: Tommy B. ThompsonSOCIETY OF ECONOMIC GEOLOGISTS

EPITHERMAL GOLD MINERALIZATION AND MODERN ANALOGUES, KYUSHU, JAPAN

Edited by Craig A. Feebrey, Toshihiko Hayashi, Sachihiro Taguchi

GUIDEBOOK SERIESVolume 34

Trip stops

ii

GUIDEBOOK SERIESof the

SOCIETY OF ECONOMIC GEOLOGISTS

SERIES EDITOR: Tommy B. Thompson

Graphic Design/Printing byJohnson Printing

1880 South 57th CourtBoulder, Colorado 80301

ISBN 1-887483-34-9

Additional copies of the guidebook maybe obtained from

Society of Economic Geologists, Inc.

7811 Shaffer Parkway

Littleton, CO 80127 USA

Telephone: (720) 981-7882

FAX: (720 981-7874

Website: <www.segweb.org> E-mail: [email protected]

Publication Date: October 2001

Cover figure: Map of Kyushu, Japan, with field trip stops indicated. Rectangles delimit the areas covered by route maps, p. viii–xi.

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ContentsPreface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vAcknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vItinerary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viRoute maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii

DAY 1Quaternary gold mineralization and it geologic environments in Kyushu, Japan (Reprint)

Eiji Izawa, and Yukitoshi Urashima . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Overview of epithermal gold mineralization in Kyushu, JapanEiji Izawa and Koichiro Watanabe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

DAY 2Route maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Hishikari gold mineralization: A case study of the Hosen no. 1 vein hosted by basement Shimanto sedimentary rocks, southern Kyushu, Japan

Eiji Izawa, Jiro Etho, Misuzu Honda, Yoshinobu Motomura, and Ryota Sekine . . . . . . . . . . . . . . . . . . . . . . 21

Geology and geophysical expression of the Yamagano low-sulfidation epithermal Au-Ag deposit, southwest Kyushu, Japan

Hiroyasu Murakami and Craig A. Feebrey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Field Stop: Geology and geophysical expression of the Yamagano low-sulfidation epithermal Au-Ag deposit, southwest Kyushu, Japan

Hiroyasu Murakami and Craig A. Feebrey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

DAY 3Route maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Kushikino gold mineralization in a Pliocene volcanic region, Kyushu, JapanEiji Izawa and Nanshi Zeng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Epithermal gold exploration in the Iriki district, Kagoshima, JapanToshihko Hayashi and Sachihiro Taguchi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Field stop: Iriki kaolin mineToshihiko Hayashi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Field stops: Kushikino gold mineToshihiko Hayashi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

DAY 4Route maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Geology, geochemistry, and origin of high-sulfidation Cu-Au mineralization in the Nansatsu district, Japan (Reprint)

Jeffrey W. Hedenquist, Yukihiro Matsuhisa, Eiji Izawa, Noel C. White, Werner F. Giggenbach, and Masahiro Aoki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Geology and gold exploration in the Nansatsu district, southern Kyushu, JapanToshihiko Hayashi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Field stops: Kasuga, Iwato, and Akeshi minesToshihiko Hayashi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

DAY 5Route maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Geology of Sakurajima volcano, southern Kyushu, JapanTetsuo Kobayashi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Field stops: SakurajimaTetsuo Kobayashi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

iv CONTENTS

DAY 6Route maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

Overview of geological and geophysical features of Aso VolcanoKoichiro Watanabe and Sachihiro Taguchi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Field stops: Aso VolcanoKoichiro Watanabe and Sachihiro Taguchi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

Kuju Iwo-yama fumaroleSachihiro Taguchi, Koichiro Watanabe, and Masahiro Komatsu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

Field stops: Kuju Iwo-yama fumaroleSachihiro Taguchi, Koichiro Watanabe, and Masahiro Komatsu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

DAY 7Route maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

Otake-Hatchobaru geothermal fieldSachihiro Taguchi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Field stops: Otake-HatchobaruSachihiro Taguchi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Occurrence and structure of the Ikiryu sinter, Kuju volcanic region, north-central Kyushu, Japan

Tetsuya Nakanishi, Sachihiro Taguchi, Koichiro Watanabe, and Eiji Izawa. . . . . . . . . . . . . . . . . . . . . . . . 181

Onta pottery (Ontayaki) and Onta-Yamakuni gold fieldRyota Sekine, Koichiro Watanabe, Sachihiro Taguchi, and Eiji Izawa . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187