Skip to Main Content
Book Chapter

Quaternary Gold Mineralization and Its Geologic Environments in Kyushu, Japan

By
Elji Izawa
Elji Izawa
Department of Mining, Kyushu University, Hakozaki, Higashi-ku, Fukuoka, Japan
Search for other works by this author on:
Yukitoshi Urashima
Yukitoshi Urashima
College of Liberal Arts, Kagoshima University, Korimoto, Kagoshima, Japan
Search for other works by this author on:
Published:
January 01, 1989

Abstract

The late Cenozoic volcanic activity in Kyushu is characterized by large-scale volcano-tectonic depressions. The sites of these depressions together with associated volcanism and gold mineralization migrated southeastward in northern Kyushu and eastward in southern Kyushu. Thus, Quaternary gold deposits in Kyushu occur within 30 km west from the present volcanic front; the Pliocene gold deposits occur farther away from the active volcanoes.

Typical Quaternary gold mineralization in Kyushu is the quartz vein type with associated adularia and minor calcite. Although host rocks are predominantly andesitic volcanic rocks and sometimes rhyolite and lacustrine sediments, the major portion of high-grade quartz veins of the Hishikari deposit discussed here is hosted in basement sedimentary rocks close to the unconformity between the basement and overlying Quaternary andesites. Five distinct alteration types are recognizable on the basis of mineral assemblages for Quaternary gold deposits. Two are the deeper propylitic alteration and the shallower smectite-zeolite alteration of the widespread and temperature-controlled type; the rest are mica-chlorite alteration, argillic alteration, and siliciflcation of the fracture-controlled type.

Most Quaternary and some Pliocene gold deposits in Kyushu are located near small Bouguer anomaly highs in areas of regional gravity anomaly lows. In the case of the youngest deposits the gravity anomaly highs are overlapped by low electrical resistivities. The small gravity anomaly highs have been ascribed to underlying uplifted blocks of basement. The low resistivity anomalies are caused by the presence of argillic alteration of the shallow portion of the mineralized systems.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables

Contents

Economic Geology Monograph Series

The Geology of Gold Deposits: The Perspective in 1988

Reid R. Keays
Reid R. Keays
Search for other works by this author on:
W. R. H. Ramsay
W. R. H. Ramsay
Search for other works by this author on:
David I. Groves
David I. Groves
Search for other works by this author on:
Society of Economic Geologists
ISBN electronic:
9781629490014
Publication date:
January 01, 1989

GeoRef

References

Related

A comprehensive resource of eBooks for researchers in the Earth Sciences

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal