Laser (U-Th)/He thermochronology of detrital zircons as a tool for studying surface processes in modern catchments

Alka Tripathy-Lang, Kip Hodges, Brian D. Monteleone, Matthijs Van Soest

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Detrital mineral thermochronology of modern sediments is a valuable tool for interrogating landscape evolution. Detrital zircon (U-Th)/He thermochronology is of particular interest because zircons are durable and withstand transport in glacial and fluvial systems far better than, for example, apatite. However, because of the time-intensive nature of conventional zircon (U-Th)/He thermochronology, most previous studies of this kind have relied on data for a few tens of grains, even though conventional wisdom holds that a substantially larger number is necessary for a robust characterization of the population of cooling ages in a sample. Here, we introduce a microanalytical approach to detrital zircon (U-Th)/He thermochronology that addresses many factors that can complicate the interpretation of conventional zircon (U-Th)/He data, particularly with respect to alpha ejection and injection and U + Th zoning. In addition, this technique permits the effective dating of naturally abraded and broken grains, and, therefore, lessens the potential for sampling bias. We apply both conventional and laser microprobe techniques to a detrital sample from the Ladakh Range in the northwestern Indian Himalaya, showing that the two yield very similar principal modes of apparent ages. However, the laser microprobe data yield a broader spectrum of ages than that of the conventional data set, which we interpret to be caused by bias related to the selection requirements for zircons used for conventional dating. This method thus provides a time-efficient route to obtaining a higher-resolution distribution of dates from a single sample, which will, in turn, yield higher-fidelity constraints regarding catchment-wide erosion rates for surface process studies.

Original languageEnglish (US)
Pages (from-to)1333-1341
Number of pages9
JournalJournal of Geophysical Research: Earth Surface
Volume118
Issue number3
DOIs
StatePublished - 2013

Fingerprint

thermochronology
Catchments
zircon
laser
catchment
dating
Lasers
lasers
apatites
ejection
erosion
sediments
sampling
routes
minerals
injection
cooling
Apatites
sampling bias
requirements

ASJC Scopus subject areas

  • Earth-Surface Processes
  • Geophysics

Cite this

Laser (U-Th)/He thermochronology of detrital zircons as a tool for studying surface processes in modern catchments. / Tripathy-Lang, Alka; Hodges, Kip; Monteleone, Brian D.; Van Soest, Matthijs.

In: Journal of Geophysical Research: Earth Surface, Vol. 118, No. 3, 2013, p. 1333-1341.

Research output: Contribution to journalArticle

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