English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  In-situ high spatial resolution LA-MC-ICPMS 230Th/U dating enables detection of small-scale age inversions in speleothems

Lin, Y., Jochum, K. P., Scholz, D., Hoffmann, D. L., Stoll, B., Weis, U., et al. (2017). In-situ high spatial resolution LA-MC-ICPMS 230Th/U dating enables detection of small-scale age inversions in speleothems. Solid Earth Sciences, 2(1), 1-9. doi:10.1016/j.sesci.2016.12.003.

Item is

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Lin, Yiming, Author
Jochum, K. P.1, Author              
Scholz, Denis, Author
Hoffmann, Dirk L., Author
Stoll, B.2, Author              
Weis, U.2, Author              
Andreae, M. O.3, Author              
Affiliations:
1Geochemistry, Max Planck Institute for Chemistry, Max Planck Society, ou_1826288              
2Climate Geochemistry, Max Planck Institute for Chemistry, Max Planck Society, ou_2237635              
3Biogeochemistry, Max Planck Institute for Chemistry, Max Planck Society, ou_1826286              

Content

show
hide
Free keywords: -
 Abstract: We present an in-situ method for Th and U isotope measurements by laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) to determine possible age inversions of stalagmites, using a 213 nm Nd:YAG laser connected to an MC-ICPMS. Due to the low ion beam intensity of 230Th (20–120 counts per second, cps), we carefully optimized the operating parameters to get highest possible ion beam intensities, i.e., laser fluence (25 J cm−2), spot size (110 μm), pulse repetition rate (20 Hz), scan speed (4 μm s−1), integration time (1000 s), and He and Ar gas flow (∼0.9 L min−1 and ∼0.6 L min−1 respectively). A precision (2 relative standard error, 2RSE) of better than 1.8% was obtained for a single 230Th/238U measurement performed on a stalagmite from Hϋttenblӓserschachthöhle, western Germany, having U concentrations of 2–7 μg g−1 and with 230Th beam intensity of less than 100 cps. Compared to previous studies (Hoffmann et al., 2009), this is the about same precision, however at lower U concentrations. The data are corrected and calibrated by two factors (F1 and F2) for 230Th/238U and 234U/238U, respectively, using a carbonate material (flowstone in secular equilibrium). We obtained an age uncertainty (2 SE, 2σ) of ca. 9 ka at ca. 215 ka. Most data agree with solution MC-ICPMS results obtained on the same sample within their uncertainties. The reproducibility of the LA-MC-ICPMS age data is within 4.5% (2RSE) as determined from 3 to 4 repeated analyses. With a spot size of 110 μm and spatial resolution of about 400 μm or higher, it is possible to see much more details in thin growing layers than conventional solution analysis, where mixed layer sampling cannot be avoided. Potential age inversions in small regions are revealed, which cannot be detected by solution analysis due to the insufficient spatial resolution.

Details

show
hide
Language(s): eng - English
 Dates: 2017-02-152017-03
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: DOI: 10.1016/j.sesci.2016.12.003
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Solid Earth Sciences
  Alternative Title : Solid Earth Sciences
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 2 (1) Sequence Number: - Start / End Page: 1 - 9 Identifier: ISBN: 2451-912X