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Posts dealing with analytical methods

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Enhanced UPbR data reduction spreadsheet

A more sophisticated UPbR data reduction (Schmitz and Schoene, 2007) sample template file containing enhancements like weighted mean calculation, comprehensive Th/U disequilibrium correction alternatives, outlier rejection calculations, and analysis of variance graphs is now available as BSULab_UPbR17-2_Anyone.xls. (Read More) Enhanced UPbR data reduction spreadsheet

Barite removal from heavy mineral separates

Barite is an occasional voluminous component of the non-magnetic heavy mineral fraction of altered volcanic tuffs and sandstones, and can swamp out the target zircon population.  Unfortunately barite is remarkably immune to dissolution in strong mineral acids. To quantitatively remove … (Read More) Barite removal from heavy mineral separates

Ultrasonic Clay Separator Device and Manuscript

This published manuscript (clay_separator_v3s) describes an efficient method for high-volume heavy mineral separation from clay-rich rocks using an ultrasonic probe. The ultrasonic clay separator (UCS) is an easily constructed device that allows for the recovery of high density minerals, as … (Read More) Ultrasonic Clay Separator Device and Manuscript

Effects of high-T annealing on CL emission

These SEM-based cathodoluminescence (CL) photomicrographs of zircon crystals illustrate the positive enhancement of CL emission resulting from high-temperature (900°C) annealing for 60 hours. All four rows of zircon crystals are from the same 1.1 Ga granitoid, and contain 100 to … (Read More) Effects of high-T annealing on CL emission

New instructional resources in the LabShare archive!

New slideshows and instructional videos are now available in LabShare! These resources demonstrate the methods we use in the IGL for both ID-TIMS and LA-ICPMS U-Pb zircon geochronology. (Read More) New instructional resources in the LabShare archive!

Volcanic ash bed dissaggregation

We have been experimenting extensively with the sediment disaggregation method of Triplehorn_(2002) using dimethyl sulfoxide (DMSO), which appears to selectively dissolve kaolinite.  We’ve found that this treatment works remarkably well for disaggregating many weakly to significantly indurated volcanic tuff samples.  … (Read More) Volcanic ash bed dissaggregation

Making shrink-teflon microcolumns for U-Pb ion chromatography

Detailed instructions for making microcolumns (50 to 100 µl) for U-Pb ion chromatography from shrink-teflon, and a lazy-susan type assembly for ≥16 simultaneous separations.  I’ve also added instructions for making larger diameter 100 µl microcolumns for common Pb separations. (Read More) Making shrink-teflon microcolumns for U-Pb ion chromatography

Supplier of quartz crucibles

We now purchase fused quartz crucibles and covers for high-T annealing zircons from AdValue Technology LLC (tel: 520-514-1100), at a significant discount compared to other large laboratory suppliers. (Read More) Supplier of quartz crucibles

Zone-refined rhenium for U-Pb

We now only use zone-refined (99.999%) rhenium ribbon from H. Cross for our U-Pb zircon analysis.  Total common Pb contents of our radiogenic Pb analyses are more consistent and lower, in the range of 0.3 to 0.5 pg; prior to … (Read More) Zone-refined rhenium for U-Pb

Mass spec cleanup

We routinely boil the stainless steel portions of our turret, bead blocks, ion source lens, and filament beads in ACS-grade hydrogen peroxide to effectively remove Re buildup (no scrubbing of slit plates or filing of used filament beads needed!) and … (Read More) Mass spec cleanup