6533b823fe1ef96bd127e2c0

RESEARCH PRODUCT

Assessment of Five Monazite Reference Materials for U-Th/Pb Dating Using Laser-Ablation ICP-MS

Delia RöselDelia RöselMassimo RaveggiThomas ZackOliver NebelRegina Mertz-krausYona Nebel-jacobsenMarianne Richter

subject

Laser ablation010504 meteorology & atmospheric sciencesMAdel94-222U-Th/Pb datinglcsh:QE1-996.5Mineralogy010502 geochemistry & geophysics01 natural sciencesTMMlcsh:GeologyMoacirUSGS 44069La icp msAbsolute datingMonaziteCalibrationmonaziteGeneral Earth and Planetary SciencesLA-ICP-MSInductively coupled plasma mass spectrometryGeologyreference material0105 earth and related environmental sciences

description

Monazite is a common accessory phosphate mineral that occurs under a wide range of pressure and temperature conditions in sedimentary, metamorphic and igneous rocks. Monazite contains high amounts of Th and U, rendering single monazite grains suitable for in-situ U-Th/Pb dating using laser ablation inductively-coupled mass spectrometry (LA-ICP-MS). Two key aspects of monazite dating that are critical for accurate age data with maximum precision are (i) optimized instrumental conditions to minimize analytical scatter and (ii) a well characterized reference material to ensure the accuracy of the obtained aged. Here, we analyzed five monazite reference materials (USGS 44069, 94-222, MAdel, Moacir and Thompson Mine Monazite) for their U-Th/Pb ages using LA-ICP-MS technique and applied a variety of laser spot diameters and repetition rates to find the best operational conditions to achieve accurate age data while maintaining maximum precision. We find that a spot diameter of 10 &micro

yearjournalcountryeditionlanguage
2019-09-06Geosciences
10.3390/geosciences9090391http://dx.doi.org/10.3390/geosciences9090391