• Rua Carlos Gomes, 250 - CEP: 13083-855 - Campinas, SP, Brasil

Image not available

  • Portuguese, Brazil
    Image not available
  • English
    Image not available
  • Spanish
    Image not available
Utilizar o username do domínio IGE
Utilizar a senha do domínio IGE
  • Reset your password
IG 45 anos
Image not available
Unicamp
Image not available

Main Menu

  • Institutional
    • Overview
    • Departments
      • DGEO
      • DGRN
      • DPCT
    • Library
      • Comission
      • Regulations
      • Team
      • Services
      • Links
      • Social Media
    • Contact
  • People
    • Faculty
    • Colaborators
    • Techical and Administrative Staff
    • Researchers
    • Postdocs
  • Undergraduate
    • Overview
    • Undergraduate in Geology
    • Undergraduate in Geography
    • Scholarships and Internships
    • Contact
  • Graduate
    • Overview
    • Programmes
      • Teaching and History of Earth Sciences
      • Geosciences
      • Geography
      • Science and Technology Policy
    • Regulations and Catalogues
    • Student Entities
    • Unicamp Teacher Internship Programme Grants
    • Grants
    • Disciplines
    • Special Students
    • Defenses and Qualifications
      • Schedule
      • Procedures for dissertation defences and qualifying exams
    • Repository of Theses and Dissertations
    • Contact
  • Research
    • Overview
    • Research resources
    • Support Office for Research and Extension Projects
    • Academic and scientific production
    • Research Groups
    • Contact
  • Laboratories
  • Culture and Extension
    • Overview
    • Outreach and Specialisation Degrees
    • Extension activities
    • Contact
  • Communication
    • News
    • Social Media

Paleoproterozoic gold deposits at Alta Floresta Mineral Province, Brazil: Two overprinted mineralizing events?

Breadcrumb

  • Home
  • Paleoproterozoic gold deposits at Alta Floresta Mineral Province, Brazil: Two overprinted mineralizing events?
Maria José
Image not available
Maria José Maluf de Mesquita
Márcia Elisa Boscato Gomes
Igor de Carvalho Moreira
Renata Augusta Sampaio Paes
Hevelyn Eduarda da Silva Martins
José Henrique da Silva Nogueira de Matos
Alberto Ruggiero
Guilherme Primo
Diego Fernando Ducart
Luciano Poggi
Vanessa Pimenta
Leonardo Zanchetta de Laurentis
André Massanobu Ueno Kunifoshita
DGRN

Large gold provinces commonly show complicated mineralization histories, and the Paleoproterozoic Alta Floresta, one of Brazil's most exciting Au–Cu mineral provinces, is a good example. The current models define four deposit types, all connected to a single (1.88–1.75 Ga) magmatic–hydrothermal event. However, long Province history, diverse geodynamic environment and older ages of type-1 mineralization weaken the single metallogenic event and enable the hypothesis of overprinted mineral events. By using scale-integrated analyses, we revise the tectonic–geological context, structural–hydrothermal alterations and chlorite–white mica geothermobarometer and propose the type-1 as an older, granitoid-hosted orogenic mineralization with subsequent overprinting by the magmatic–hydrothermal event. The older orogenic gold event developed orogenic gold deposits on WNW-trending shear zones in the Peixoto de Azevedo domain granitic–gneiss rocks. Phengite, biotite, chlorite–carbonate phyllonites (3.3–6.1 kbar, 300–420°C) host fault-fill quartz veins (pyrite–chalcopyrite–magnetite–pyrrhotite–gold–Bi–Ag tellurides). Mg-rich chlorite–phengite is the main alteration footprint for this mineralization type. A younger magmatic–hydrothermal event in the Juruena magmatic–arc rocks produced Ferich chlorite–white mica alteration zones (0.6–4.6 kbar, 120–380°C) and disseminated and stockwork–breccia ore (pyrite–chalcopyrite–gold–molybdenite– Ti minerals–allanite) in porphyry–epithermal deposits. Where the younger mineralization overprints the older, phyllic alteration destroyed the phengite orogenic gold phyllonite Sn+1 foliation. The ages of two pyrite populations (1979 and 1841 Ma) in the older fault-fill veins and molybdenite in late fractures (1805–1782 Ma) or disseminated in the ca. 1.79 Ga syenogranite porphyry suggest more than two episodes of mineralization. These two events differ in their alteration styles, P–T conditions, and structural, mineralogical and textural ore styles. The multi-scale approach enlightens the relationships between the various mineralization events, allowing a new explorational potential within the province.

Maria José Maluf Mesquita

Diego Fernando Ducart

The Geological Society

Address

Rua Carlos Gomes, 250
CEP: 13083-855
Campinas, SP

Directions 

22º48'48"S 47º04'09"W

Footer menu

  • Portal Feedback

Links

  • Email Unicamp
  • Sistemas e Solicitações
  • Intranet (antiga)
  • Logotipos do IG
  • Contacts

Menu do usuário

  • Log in
IG 45 anos
Unicamp

Copyright © 2025 IG, Unicamp. Todos os direitos reservados

Notifications