Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Rowley, D. B. Search for Related Content GeoRef GeoRef Citation

Stable Isotope-Based Paleoaltimetry: Theory and Validation

Department of the Geophysical Sciences, The University of Chicago, 5734 S. Ellis Avenue, Chicago, Illinois, 60637, U.S.A., rowley{at}geosci.uchicago.edu

Paleoaltimetry is the quantitative estimate of the surface height above mean sea level of ancient landforms. Atmospheric thermodynamic modeling of the behavior of ¹⁸O relative to ¹⁶O during condensation from water vapor establish the systematic relationship that exists between ( ¹⁸O_p) and elevation, where (¹⁸O_p) is the difference between a low altitude, preferably sea level ¹⁸O_p and a potentially high elevation sample. Comparison of model predictions with observations suggests that the model captures the first-order behavior of ¹⁸O_p during condensation and precipitation in orographic settings. The actual relationship between ( ¹⁸O_p) and elevation depends sensitively on climate, and specifically starting temperature and to a lesser degree relative humidity. Thermodynamic modeling allows the (¹⁸O_p) and elevation relationship to be explicitly calculated for any given starting climate state. This makes the theoretical approach significantly more appropriate than empirically calibrated approaches based typically on quite limited samples presently available in most orographic settings today.

Paleoaltimetry archives derive their isotopic compositions from surface and or ground water, and hence it is important to understand the systematic differences between these reservoirs and precipitation. Surface waters and ground waters integrate not just the change in isotopic composition with altitude, but also variations in hypsometry within the drainage basin and precipitation amount as functions of elevation. Thus these archives should reflect the precipitation amount weighted hypsometric mean elevation of the (paleo)-drainage basin from which they derive their waters. Analysis of modern data from the Himalayan region supports this expectation. Foreland basin rivers are such integrators and it is shown, using an example from the Siwaliks that the rivers draining the front of the Himalayas in the past had isotopic compositions comparable with modern rivers draining the Himalayan front suggesting little net change in Himalayan hypsometry over the past 11 million years.

This article has been cited by other articles:

				E. J. Cassel, S. A. Graham, and C. P. Chamberlain Cenozoic tectonic and topographic evolution of the northern Sierra Nevada, California, through stable isotope paleoaltimetry in volcanic glass Geology, June 1, 2009; 37(6): 547 - 550. [Abstract] [Full Text] [PDF]

				A. Mulch, A. M. Sarna-Wojcicki, M. E. Perkins, and C. P. Chamberlain A Miocene to Pleistocene climate and elevation record of the Sierra Nevada (California) PNAS, May 13, 2008; 105(19): 6819 - 6824. [Abstract] [Full Text] [PDF]

				M. K. Clark The Significance of Paleotopography Reviews in Mineralogy and Geochemistry, October 1, 2007; 66(1): 1 - 21. [Abstract] [Full Text] [PDF]

				M. J. Kohn and D. L. Dettman Paleoaltimetry from Stable Isotope Compositions of Fossils Reviews in Mineralogy and Geochemistry, October 1, 2007; 66(1): 119 - 154. [Abstract] [Full Text] [PDF]

				C. A. Riihimaki and J. C. Libarkin Terrestrial Cosmogenic Nuclides as Paleoaltimetric Proxies Reviews in Mineralogy and Geochemistry, October 1, 2007; 66(1): 269 - 278. [Abstract] [Full Text] [PDF]