Lyell Collection
Geochemistry: Exploration, Environment, Analysis
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
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
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Åström, M. E.
Right arrow Articles by Salminen, R.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Geochemistry: Exploration, Environment, Analysis; 2008; v. 8; issue.2; p. 139-148;
DOI: 10.1144/1467-7873/07-155
© 2008 Geological Society of London

Original Article

Niobium in boreal stream waters and brackish-water sediments

Mats E. Åström1, Pasi Peltola1, Joonas J. Virtasalo2, Aarno T. Kotilainen3 & Reijo Salminen3

1 Kalmar University, School of Pure and Applied Natural Sciences, S-39182 Kalmar, Sweden (mats.astrom{at}hik.se)
2 University of Turku, Department of Geology, FI-20014 Turku, Finland
3 Geological Survey of Finland, FI-02151 Espoo, Finland

The focus is on ‘non-detrital’ Nb in boreal stream waters (dissolved fraction and acid-available particulate fraction) and brackish-water/lacustrine sediments (aqua regia extractable fraction). Spatial patterns, temporal trends and speciation experiments all point to dissolved humic substances and colloidal Fe as the main control of Nb concentrations in stream waters. In addition, clay-silt deposits and/or ore deposits may be responsible for producing local streamwater Nb anomalies. In groundwater in overburden (glacial till) overlying Proterozoic granitoids, dissolved Nb concentrations were about an order of magnitude higher than in stream waters and strongly correlated with dissolved Fe. In the brackish-water sediments, the Nb concentrations (1.33–4.20 ppm) were higher than in the lacustrine ones (0.25–0.53 ppm). To explain this, we assessed the potential role of organic material, biological processes, sulphide mineralogy, silicate mineralogy and input factors. However, none of them could satisfactorily explain the observed Nb geochemical features. Although Nb can be considered relatively immobile, the data presented in this paper show that under certain conditions its abundance in the aquatic environment increases.

Key Words: niobium • stream water • boreal • sediment • humus • speciation