Geochemical Studies of Rare Earth Elements in the Portuguese Pyrite Belt, and Geologic and Geochemical Controls on Gold Distribution Edited by David J. Grimes and S.J. Kropschot A. Rare Earth Element Distribution in the Volcanic Lithostratigraphic Units of the Portuguese Pyrite Belt By David J. Grimes, Robert L. Earhart, and Delfim de Carvalho B. Geologic Setting and Geochemical Controls on the Distribution of Gold in the Portuguese Pyrite Belt By Robert L. Earhart, Delfim de Carvalho, Vitor Oliveira, Jose T. Oliveira, and Paulo Castro T OF EN TH U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1596–A–B TM E R I A N P T E E R D . I O S . R U Prepared in cooperation with the Luso American Development Foundation, the M Serviços Geológicos de Portugal, and the Serviço A 4 9 R 18 de Fomento Mineiro C H 3, UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1998 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Thomas J. Casadevall, Acting Director For sale by U.S. Geological Survey, Information Services Box 25286, Federal Center Denver, CO 80225 Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government Library of Congress Cataloging-in-Publication Data Geochemical studies of rare earth elements in the Portuguese Pyrite Belt, and geologic and geochemical controls on gold distribution / edited by David J. Grimes and S. J. Kropschot. p. cm.—(U.S. Geoloigcal Survey professional paper ; 1596) “Prepared with the support and cooperation of the Luso American Development Foundation, the Serviços Geológicos de Portugal, and the Serviços de Fomento Mineiro.” Includes bibliographical references. Contents: Rare earth element distribution in the volcanic lithostratigraphic units of the Portuguese Pyrite Belt / by David J. Grimes, Robert L. Earhart, and Delfim de Carvalho — Geologic setting and geochemical controls on the distribution of gold in the Portuguese Pyrite Belt / by Robert L. Earhart . [et al.]. 1. Geochemistry—Portugal. 2. Rare earth metals—Portugal. 3. Gold ores— Portugal. I. Grimes, D. J. (David J.), 1943–. II. Kropschot, S. J. (Susan J.) III. Luso-American Development Foundation. IV. Serviços Geológicos de Portugal. V. Portugal, Serviços de Fomento Mineiro. VI. Series. 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