Isotopic Analysis of Minerals for Geochronology and Source Tracing using Small Ablation Spots
The TTU MILL Mineral Isotope Laser Laboratory
Instrumentation consists of a Nu Plasma II MC-ICP-MS, a Nu AttoM magnetic sector, single-collector ICP-MS, and an ESI NWR193 laser ablation system with a 193 nm ArF excimer laser and a TwoVol2 two-volume ablation chamber. The AttoM is used for U-Th-Pb geochronology and the Plasma II is used for isotope tracer analyses (e.g. in-situ Lu-Hf isotope analyses). Data can be acquired manually or in fully automated mode.
Research Analyses
Using in situ analyses of minerals to determine the timing of crystallization and/or recrystallization and source of the magmas and/or fluids involved.
Mineral grains may be analyzed in epoxy mounts or directly in polished thin sections. Cathodoluminescence (CL) or high-contrast backscattered electron (BSE) images should be collected prior to arrival in the LA-ICP-MS laboratory in order to guide the placement of ablation spots for age measurements. Reference mineral materials such as 91500, Plesovice, Temora-2 and OG-1 zircons are used for calibration and/or quality assurance/control. Data are processed using Iolite and assessed for final isotopic ratios and age determinations using the VizualAge DRS and IsoplotR.
U-Pb Zircon Geochronology
Hf Isotope Zircon Geochemistry
U-Pb Geochronology of Other Minerals
LA-ICP-MS U-Pb geochronology of zircon using the Nu AttoM magnetic sector is the most common type of analysis performed in the laboratory. We specialize in the use of small ablation spots, 7-15 microns, for U-Pb analyses of small grains or small domains such as inherited cores or overgrowth rims of larger grains.
Laser ablation analysis for Hf-isotope geochemistry of zircon is performed using the Nu Plasma II multicollector magnetic sector. Spots must be somewhat larger than the 7-15 microns used for U-Pb ages to achieve 1epsilon Hf precision, and are commonly placed over the U-Pb age pits.
Apatite, rutile, monazite, and titanite may also be measured for U-Th-Pb age by LA-ICP-MS using the Nu AttoM. Spots sizes can be as small as those used for zircon depending on the U and Th contents. Where necessary, common Pb corrections are made using Stacey-Kramers crustal Pb or Nu Plasma II measurements of common Pb in feldspar coexisting with the dated mineral.
Published Work
Literature references relevant to laboratory methods
January 2019
Laser Ablation ICP-MS U-Pb Geochronology with Small Spots
Mukherjee, P. K., Souders, A. K., & Sylvester, P. J. (2019). Accuracy and precision of U–Pb zircon geochronology at high spatial resolution (7–20 μm spots) by laser ablation-ICP-single-collector-sector-field-mass spectrometry. Journal of Analytical Atomic Spectrometry, 34(1), 180-192.
October 2016
A Brief History of Laser
Ablation Inductively Coupled
Plasma Mass Spectrometry
Sylvester, P. J., & Jackson, S. E. (2016). A Brief History of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA–ICP–MS). Elements, 12(5), 307-310.
September 2016
Data Reporting Procedures for LA-ICP-MS U-Pb Geochronology
Horstwood, M. S., Košler, J., Gehrels, G., Jackson, S. E., McLean, N. M., Paton, C., Pearson, N.J., Sircombe, K., Sylvester, P., Vermeesch, P. & Bowring, J. F. (2016). Community‐derived standards for LA‐ICP‐MS U‐(Th‐) Pb geochronology–Uncertainty propagation, age interpretation and data reporting. Geostandards and Geoanalytical Research, 40(3), 311-332.
September 2013
Laser Ablation ICP-MS U-Pb Geochronology of Detrital Zircon
Košler, J., Sláma, J., Belousova, E., Corfu, F., Gehrels, G. E., Gerdes, A., Horstwood, M.S., Sircombe, K.N., Sylvester, P.J., Tiepolo, M. & Whitehouse, M. J. (2013). U‐Pb detrital zircon analysis–Results of an inter‐laboratory comparison. Geostandards and Geoanalytical Research, 37(3), 243-259.
January 2013
LA-MC-ICP-MS measurements of Lu-Hf isotopes in zircon and common Pb isotopes in feldpsar
Souders, A. K., Sylvester, P. J., & Myers, J. S. (2013). Mantle and crustal sources of Archean anorthosite: a combined in situ isotopic study of Pb–Pb in plagioclase and Lu–Hf in zircon. Contributions to Mineralogy and Petrology, 165(1), 1-24.
January 2011
Laser Ablation ICP-MS U-Pb and Th-Pb Geochronology of Apatite
Chew, D. M., Sylvester, P. J., & Tubrett, M. N. (2011). U–Pb and Th–Pb dating of apatite by LA-ICPMS. Chemical Geology, 280(1-2), 200-216.
Current Staff
Laboratory Team Members with Diverse Expertise
Diversity, Equity & Inclusion Statement: MILL celebrates diversity and is committed to strengthening equity and fostering an inclusive environment for all.
We aim to provide a supportive community that empowers each individual and embraces individuals of all social and intrinsic backgrounds.
Prof. Paul Sylvester
Pevehouse Chair Professor
Principle Investigator
Dr. Kate Souders
United States Geological Survey - Denver
Adjunct Faculty - TTU Geosciences
Mr. Rui Liu
Ph.D. Student Research Assistant
Current Staff
Laboratory Team Members with Diverse Expertise
Mr. Alex Washburn
Ph.D. Student Research Assistant
Mr. Chris Reudelhuber
MS. Student Research Assistant
Mr. Austin Bertoch
MS. Student Research Assistant
Former Group Members
Career Professionals
Ms. Suzanne Ji, M.Sc
Section Managing Editor of /Climate/ MDPI Journals
Ms. Angela Norman, MS.
Exploration Geologist, Newfoundland
Mr. Matthew Scott, M.Sc
C-NLOPB Development Geologist, Newfoundland
Contact Us
1008 Canton Ave
Experimental Sciences Building
Room 157
Texas Tech University
Lubbock, TX 79409-3132 USA
806-834-5091