Skip to main content
padlock icon - secure page this page is secure

Genesis, mineralogy and geochemistry of kaolin deposits of the Jari River, Amapá State, Brazil

Buy Article:

$20.00 + tax (Refund Policy)

Kaolin samples from the Jari deposit (Amazon region) were studied using various techniques to characterize its structural and crystallochemical aspects, and to establish its origin and evolution. A profile 60 m thick was selected in a kaolin mine (Morro do Felipe) located at the banks of the Jari river. Despite the great thickness of the deposit and the variety of kaolin types, the mineralogical composition is rather homogeneous and is mainly kaolinite associated with gibbsite and small amounts of quartz, anatase, goethite and hematite. The field observations and the morphological analysis indicate the existence of sedimentary features throughout the whole profile except for the upper aluminous clayey layer (Belterra Clay). This is evidence that the Rio Jari kaolin deposit originated from sedimentary material, the Alter do Chão Formation. The presence of alternating clay and sandy layers is explained by sedimentation processes with great depositional energy variation. Thus, the accumulation of thick clay layers was related to a lowenergy phase, and during the high-energy phases, the deposition process led to the accumulation of sandy materials, constituted essentially of quartz and showing strong textural and structural variation. Later on, periods of hydromorphy were responsible for iron removal and consequently for the bleaching of the sedimentary formation. The crystallinity data show an increase of the structural disorder toward the surface associated with an increase in the amount of structural Fe in the kaolinite. The Rio Jari kaolin deposits should be considered as having originated from kaolinitic clay sediments of the Alter do Chão formation (protore) that was submitted to intensive lateritic weathering processes.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Keywords: AMAZON REGION; GENESIS; GEOCHEMISTRY; KAOLIN; KAOLINITE; MINERALOGY; RIO JARI.

Document Type: Research Article

Publication date: 01 August 2002

More about this publication?
  • The JOURNAL publishes articles of interest to the international community of clay scientists, including but not limited to areas in mineralogy, crystallography, geology, geochemistry, sedimentology, soil science, agronomy, physical chemistry, colloid chemistry, ceramics, petroleum engineering, foundry engineering, and soil mechanics. Clays and Clay Minerals exists to disseminate to its worldwide readership the most recent developments in all of these aspects of clay materials. Manuscripts are welcome from all countries.

    Clays and Clay Minerals is the official publication of The Clay Minerals Society.

    The Editor-in-Chief is Professor Joseph W. Stucki [email protected]

    Publications of The Clay Minerals Society
    Source Clays

  • Editorial Board
  • Information for Authors
  • Membership Information
  • Annual Meeting of The Clay Minerals Society
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
UA-1313315-24
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more