The TTU MILL Mineral Isotope Laser Laboratory

Name: TTU MILL Mineral Isotope Laser Laboratory
Address: 2500 Broadway, Lubbock, TX, 79409, US
Telephone: 806-834-5091

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

20170504_GCH5371_method_and_gas_paramete

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

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We aim to provide a supportive community that empowers each individual and embraces individuals of all social and intrinsic backgrounds.