Skip to Main Content
Book Chapter

Field Stop: Geology and Geophysical Expression of the Yamagano Low-Sulfidation Epithermal Au-Ag Deposit, Southwest Kyushu, Japan

By
Hiroyasu Murakami
Hiroyasu Murakami
Metal Mining Agency of Japan, Tokiwa Bldg., 1-24-14, Toranomon, Minato-ku, Tokyo 105-0001, Japan
Search for other works by this author on:
Craig A. Feebrey
Craig A. Feebrey
Metal Mining Agency of Japan, Tokiwa Bldg., 1-24-14, Toranomon, Minato-ku, Tokyo 105-0001, Japan
Search for other works by this author on:
Published:
January 01, 2001

Abstract

Turn off the main road and move toward field stop 1. Participants can observe variations in alteration starting with patchy occurrences of zone I, followed by zone II, and finally by zone iii assemblages, representing a progressive increase in paleohydrothermal fluid temperatures associated with mineralization. Field stop 1 is located above the southern vein system in the vicinity of Takasuka vein and within zone III alteration, which is characterized by the assemblage quartz + interstratified illite/smectite ± kaolinite (Fig. 1). Analyses from these veins have been as high as 27.7 g/t, and fluid inclusions from the same veins indicate temperatures of about 200° to 250°C (figs. 4 and 5, Murakami and Feebrey, 2001). Also at this location silicified Nagano Formation rocks essentially cap and have preserved mineralization. Sedimentary bedding planes of the Nagano Formation are also still evident in some localities (Figs. 2 and 3).

Also of particular interest in terms of exploration for this style of mineralization is the excellent correspondence between the distribution of mapped zone III alteration, characterized by interstratified illite/smectite, and the area of extremely high K counts obtained during a high-resolu- tion airborne radiometric survey. Points of interest include the amount of vegetation that exists and covers zone III alteration, indicating that significant anomalies are still evident in areas with moderate to high vegetation cover.

You do not currently have access to this article.

Figures & Tables

Contents

Society of Economic Geologists Guidebook Series

Epithermal Gold Mineralization and Modern Analogues, Kyushu, Japan

Craig A. Feebrey
Craig A. Feebrey
Search for other works by this author on:
Toshihiko Hayashi
Toshihiko Hayashi
Search for other works by this author on:
Sachihiro Taguchi
Sachihiro Taguchi
Search for other works by this author on:
Society of Economic Geologists
Volume
34
ISBN electronic:
9781934969878
Publication date:
January 01, 2001

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal