Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Geology Signup for GSW Email News
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Geology; February 2002; v. 30; no. 2; p. 107-110; DOI: 10.1130/0091-7613(2002)030<0107:POGA>2.0.CO;2
© 2002 Geological Society of America
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 reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (27)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bethke, C. M.
Right arrow Articles by Johnson, T. M.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Paradox of groundwater age

Craig M. Bethke*,1 and Thomas M. Johnson*,1

1 Department of Geology, University of Illinois, Urbana, Illinois 61801, USA

Groundwater in aquifers is generally older than expected on the basis of flow velocity, and this observation has important implications for interpreting radiometric age determinations. Hydrologists commonly account for the aging of water as it flows along streamtubes, but not for the effects of mixing old water from aquitards (or confining layers) into aquifers, because the rate of mass exchange between aquifers and aquitards can in many cases be assumed to be small. We show, however, that the effect on age of such mixing does not depend on the mixing rate; this is the paradox of groundwater age. Surprisingly, the contribution of aquitards to the age of groundwater in aquifers depends only on the ratio of fluid volume in aquitards to aquifers. This result has broad importance for understanding the relationship between groundwater flow and the distribution of radiometric age.

Key Words: groundwater age • residence time • radiometric age dating




This article has been cited by other articles:


Home page
 Reviews in Mineralogy and GeochemistryHome page
C. I. Steefel and K. Maher
Fluid-Rock Interaction: A Reactive Transport Approach
Reviews in Mineralogy and Geochemistry, January 1, 2009; 70(1): 485 - 532.
[Full Text] [PDF]

Home page
 GeosphereHome page
M. Person, A. Banerjee, A. Hofstra, D. Sweetkind, and Y. Gao
Hydrologic models of modern and fossil geothermal systems in the Great Basin: Genetic implications for epithermal Au-Ag and Carlin-type gold deposits
Geosphere, October 1, 2008; 4(5): 888 - 917.
[Abstract] [Full Text] [PDF]

Home page
 Bulletin of the Seismological Society of AmericaHome page
L. Matias, A. Ribeiro, M. A. Baptista, N. Zitellini, J. Cabral, P. Terrinha, P. Teves-Costa, and J. M. Miranda
Comment on "Lisbon 1755: A Case of Triggered Onshore Rupture?" by Susana P. Vilanova, Catarina F. Nunes, and Joao F. B. D. Fonseca
Bulletin of the Seismological Society of America, December 1, 2005; 95(6): 2534 - 2538.
[Full Text] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Geological Society of America