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Earth and Environmental Sciences

M.Sc. Thesis Proposal, “Microanalysis of Magnesium Isotope Abundances in Carbonate Minerals Using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS): Validation and Application to Hydrocarbon Reservoirs”

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  • Thu, 05/11/2017 - 3:00pm




The Department of Earth & Environmental Sciences is pleased to announce

 

EES M.Sc. Thesis Proposal

“Microanalysis of Magnesium Isotope Abundances in Carbonate Minerals Using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS):  Validation and Application to Hydrocarbon Reservoirs”
 

Namir Al-Aasm

 

Abstract

The nature of a given dolomitized hydrocarbon reservoir and the host rocks is a function of many properties, both chemical and physical; one of the defining factors being the nature of the dolomitizing fluids infiltrating host rocks and the interaction between them. These diagenetic fluids impart a unique “isotopic signature or fingerprint” on the rocks they form; this “fingerprint” being the ratio between possible isotopes of that element, the three (24Mg, 25Mg, and 26Mg) stable isotopes of magnesium in this case. These “fingerprints” are paramount in characterizing the history and formational conditions of a given deposit. Isotopic and elemental geochemistry has proven to be an invaluable tool in understanding the earth and its various geologic processes. Much of that work has relied on the use of stable isotope mass spectrometry. ICP-MS has been used to measure both the isotopic and elemental composition of geologic samples for decades, typically by conventional time consuming and costly wet chemistry analytical methods that rely on solution nebulization (SN) of a sample prepared in the form of an aqueous solution. Recent advances and breakthroughs in laser technology has made the use of laser ablation (LA) an attractive analytical method for geochemists due to its enhanced operational flexibility, lower cost and effort required in preparing and analyzing samples, as well as the ability to perform in-situ isotopic and elemental compositional analysis that can be spatially resolved in three dimensions. Advances in both higher accuracy ICP-MS and shorter pulse duration lower wavelength lasers (operating on the order of femtoseconds in the deep ultraviolet wavelength) shows promising applications in a magnesium isotopic system where isotopic fractionation of Mg and the resulting mass bias induced measuring inaccuracy can be mitigated and minimized; allowing for higher resolution sampling in 3D on the scale of tens of microns by way of controlled ablation of a solid sample. Once isotopic fractionation of Mg, and the mass bias it introduces into measurements is compensated for, laser ablation will likely become the preferred method of in-situ analysis of geologic samples containing magnesium.

This study will validate the hypothesis that laser ablation (LA) can be applied to Mg isotopic measurements in dolomite while matching and/or exceeding the accuracy attained by conventional solution nebulization (SN). Methods and equipment used will focus on measuring and establishing baseline measurements of prepared standards using an atomizing nebulizer before attempting to replicate the results using a Quantronix Integra-C femtosecond Ti:Sapphire laser to ablate the same standard sample in situ. Zoned saddle dolomite samples obtained from two carbonate reservoirs in the Kurdistan region of Iraq and Western Canada will be analyzed for their Mg isotopic ratios to quantify the origin and source of pore fluids responsible for diagenesis of carbonate rock.

 

Supervisor: Dr. Joel Gagnon
Co-Supervisor: Dr. Ihsan Al-Aasm
Program Reader: Dr. Ali Polat
Outside Program Reader: Dr. Scott Mundle

Thursday, May 11, 2017 at 3:00 p.m.

 201 Room, Memorial Hall

All Are Wecome



Marg Mayer
mmayer@uwindsor.ca
(519)253-3000 ext.2528