Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Clays and Clay Minerals Email Content Delivery
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Clays and Clay Minerals; June 2002; v. 50; no. 3; p. 381-387
© 2002 Clay Minerals Society
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jin, Z.
Right arrow Articles by Lu, X.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

TWO ORIGINS OF ILLITE AT THE DEXING PORPHYRY Cu DEPOSIT, EAST CHINA: IMPLICATIONS FOR ORE-FORMING FLUID CONSTRAINT ON ILLITE CRYSTALLINITY

Zhangdong Jin1,2,*, Jinchu Zhu2, Junfeng Ji2, Fuchun Li2 and Xinwei Lu2,3

1 Lake Sediment and Environment Laboratory, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China
2 State Key Laboratory for Research of Mineral Deposits, Department of Earth Sciences, Nanjing University, Nanjing 210093, China
3 Institute of Geography, Chinese Academy of Sciences, Beijing 100101, China

* E-mail address of corresponding author: zhdjin{at}niglas.ac.cn

Illite is a distinctive clay mineral formed by K alteration within hydrothermal alteration zones in porphyry Cu deposits. Based on differences in spatial distribution, Kübler index, number of swelling layers, and polytype, two kinds of illite are recognized within the Dexing porphyry Cu deposit, East China. One is a hydrothermal mineral within hydrothermally-altered granodiorite porphyry and altered tuffaceous phyllite near the contact zone with the granodiorite porphyry cupola. The hydrothermal illite is formed by illitization of plagioclase and/or micas during hydrothermal fluid-rock interaction. The considerable variation of their higher Kübler indices (0.17–1.41°{Delta}2{theta}) with swelling layer is affected by fluid/rock ratio or fluid flux. The other type of illite is a product of low-grade metamorphism within tuffaceous phyllite away from the porphyry cupola (>2 km), and has a lower Kübler index (0.06–0.13°{Delta}2{theta}), a 2M1 polytype, and no swelling layers. We suggest that, within the mineralized alteration zone, the lower the Kübler index, the stronger the degree of alteration, and the higher the copper grade. This is caused by a higher fluid/rock ratio in the middle–upper portions of the contact zone.

Key Words: Alteration • Hydrothermal Fluid • Kübler Index • Low-grade Metamorphism • Porphyry Cu Deposit




This article has been cited by other articles:


Home page
 Clays and Clay MineralsHome page
E. M. Bongiolo, P. Patrier-Mas, A. S. Mexias, D. Beaufort, and M. L. L. Formoso
SPATIAL AND TEMPORAL EVOLUTION OF HYDROTHERMAL ALTERATION AT LAVRAS DO SUL, BRAZIL: EVIDENCE FROM DIOCTAHEDRAL CLAY MINERALS
Clays and Clay Minerals, April 1, 2008; 56(2): 222 - 243.
[Abstract] [Full Text] [PDF]

Home page
 Economic GeologyHome page
M. Franchini, A. Impiccini, L. Meinert, G. Grathoff, and I. B.A. Schalamuk
Clay Mineralogy and Zonation in the Campana Mahuida Porphyry Cu Deposit, Neuquen, Argentina: Implications for Porphyry Cu Exploration
Economic Geology, January 1, 2007; 102(1): 27 - 54.
[Abstract] [Full Text] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Clay Minerals Society