Home | Contact Us | Sitemap | 中文 | CAS | Director's Email
 
Location:Home > Papers > Recent Papers
Geology setting and metallogenesis of the Alta Floresta Province, southern Amazon Craton (Brazil) TEXT SIZE: A A A
The Alta Floresta Province consists of Paleoproterozoic plutonic-volcanic sequences (2.01-1.75 Ga) originated from a series of successive magmatic arcs that accreted to the southwestern margin of the Central Amazon Province. The geologic framework of the eastern sector of the province is organized into: 2.8-1.97 Ga deformed metamorphic and metamorphosed granitic basement; 1.97-1.78 Ga I-type plutonic-volcanic and volcano-sedimentary sequences; 1.78-1.77 Ga post-orogenic and anorogenic plutonic-volcanic units; and Mesoproterozoic (similar to 1.3 Ga) to Quaternary sedimentary sequences. The ore deposits are clustered into four main groups: (i) disseminated Au-Cu-Mo; (ii) structurally-controlled vein-type Au-Cu-Mo; (iii) disseminated Cu-Mo; and (iv) structurally-controlled vein-type Au-Zn-Pb-Cu. Groups (i) to (iii) are characterized by pyrite-chalcopyrite-molybdenite, whereas group (iv) consists of pyrite-sphalerite-galena-chalcopyrite-digenite. In most deposits, mineralization is contained within muscovite-chorite-quartz-rich or silica-rich zones. The fluid regime of groups (i) and (ii) is mainly represented by CO2-rich fluids, whereas group (iv) by two-phase aqueous fluids with heterogeneous degree of filling. Re-Os on pyrite and molybdenite and Pb-Pb on pyrite geochronology systematics constrain the mineralization age between 1.84 - 1.77 Ga. This overlaps with the ages of porphyritic granitoids, and in a regional scale with ages of the Colider and Teles Pires suites. These deposits represent magmatic-hydrothermal systems and are considered to share broad similarities with porphyry-epithermal deposits.
 

Publication name

 LIFE WITH ORE DEPOSITS ON EARTH, PROCEEDINGS OF THE 15TH SGA BIENNIAL MEETING, 2019, VOLS 1-4 Book Group Author(s):SGA Pages: 1109-1112 Published: 2019

Conference
 
 Conference: 15th SGA Biennial Meeting on Life with Ore Deposits on Earth 
 Location: Univ Glasgow, Glasgow, SCOTLAND
 Date: AUG 27-30, 2019 

Author(s)

 Trevisan, Veronica; Xavier, Roberto; Hagemann, Steffen; Kemp, Anthony; Loucks, Robert; Gao, Jian-Feng

Corresponding author(s) 

 Trevisan, Veronica 
 Univ Estadual Campinas, Inst Geosci, Campinas, SP, Brazil

Author(s) from IGCAS   GAO Jianfeng

View here for the details 

Copyright © Institute Of Geochemistry, Chinese Academy of Sciences All Rights Reserved.
Address: 99 West Lincheng Road, Guanshanhu District, Guiyang, Guizhou Province 550081, P.R.China
Tel: +86-851-85895239 Fax: +86-851-85895239 Email: web_en@mail.gyig.ac.cn