TY - JOUR
T1 - U-Pb dating of detrital zircons for sediment provenance studies - A comparison of laser ablation ICPMS and SIMS techniques
AU - Košler, Jan
AU - Fonneland, Hege
AU - Sylvester, Paul
AU - Tubrett, Mike
AU - Pedersen, Rolf Birger
N1 - Funding Information:
The MUN laser ablation ICPMS facility is supported by NSERC through MFA funding. The high-resolution ion microprobe facility in Stockholm (Nordsim) is jointly funded by Denmark, Finland, Norway and Sweden (this is a Nordsim publication no. 52). HCF would like to acknowledge the staff at Nordsim for supervision and assistance, while obtaining the SIMS zircon ages and Norsk Hydro for financial support. This paper has benefited from constructive reviews by George Gehrels and Ingo Horn. We also thank Roberta Rudnick for an effective editorial handling of the manuscript.
PY - 2002
Y1 - 2002
N2 - New developments in U-Pb dating of zircons by laser ablation (LA) ICPMS are described and, for the first time, a direct comparison of detrital zircons dated by LA ICPMS and SIMS methods is presented. True real-time mass bias correction is made by aspirating a T1/U tracer at the same time as laser ablation. The method is similar to that described in Horn et al. (2000), except that enriched 233U rather than 235U is used in the tracer solution. Correction for laser-induced Pb/U elemental fractionation is based on a mathematical treatment of time-resolved data that is independent of laser ablation characteristics and does not require external standardisation. Internal corrections for mass bias and elemental fractionation eliminate the effects of variable sample matrix on isotopic ratios and improve the accuracy of U-Pb dating by laser ablation ICPMS. With the proper error propagation, the precision of U-Pb age determinations is only slightly worse than SIMS-based ion probe dating. However, LA ICPMS is capable of much more rapid analysis of the large number of zircons required for sediment provenance studies. There is excellent agreement between concordant laser ablation ICPMS and SIMS analyses of detrital zircons extracted from lower Silurian metasandstone from the Ulven Group (Skarfjell Formation) in the west Norwegian Caledonian nappes. Both LA ICPMS and SIMS U-Pb zircon ages indicate that sedimentary detritus of the Ulven Group was supplied from a terrain containing zircons of Archean, Proterozoic and early Ordovician age.
AB - New developments in U-Pb dating of zircons by laser ablation (LA) ICPMS are described and, for the first time, a direct comparison of detrital zircons dated by LA ICPMS and SIMS methods is presented. True real-time mass bias correction is made by aspirating a T1/U tracer at the same time as laser ablation. The method is similar to that described in Horn et al. (2000), except that enriched 233U rather than 235U is used in the tracer solution. Correction for laser-induced Pb/U elemental fractionation is based on a mathematical treatment of time-resolved data that is independent of laser ablation characteristics and does not require external standardisation. Internal corrections for mass bias and elemental fractionation eliminate the effects of variable sample matrix on isotopic ratios and improve the accuracy of U-Pb dating by laser ablation ICPMS. With the proper error propagation, the precision of U-Pb age determinations is only slightly worse than SIMS-based ion probe dating. However, LA ICPMS is capable of much more rapid analysis of the large number of zircons required for sediment provenance studies. There is excellent agreement between concordant laser ablation ICPMS and SIMS analyses of detrital zircons extracted from lower Silurian metasandstone from the Ulven Group (Skarfjell Formation) in the west Norwegian Caledonian nappes. Both LA ICPMS and SIMS U-Pb zircon ages indicate that sedimentary detritus of the Ulven Group was supplied from a terrain containing zircons of Archean, Proterozoic and early Ordovician age.
KW - Instrument mass bias
KW - Laser ablation ICPMS
KW - SIMS
KW - Sediment provenance
KW - U-Pb zircon geochronology
UR - http://www.scopus.com/inward/record.url?scp=0036194752&partnerID=8YFLogxK
U2 - 10.1016/S0009-2541(01)00341-2
DO - 10.1016/S0009-2541(01)00341-2
M3 - Article
AN - SCOPUS:0036194752
SN - 0009-2541
VL - 182
SP - 605
EP - 618
JO - Chemical Geology
JF - Chemical Geology
IS - 2-4
ER -