scholarly journals U-Pb dating by zircon dissolution method using chemical abrasion

2012 ◽  
Vol 84 (2) ◽  
pp. 399-405
Author(s):  
Lucy Takehara ◽  
Farid Chemale Júnior ◽  
Léo A. Hartmann ◽  
Ivo A. Dussin ◽  
Koji Kawashita
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Mass Spectrometer ◽  
Ionization Mass ◽  
Zircon Age ◽  
Dissolution Method ◽  
Laser Ablation Method ◽  
Thermal Ionization Mass Spectrometer ◽  
Thermal Ionization Mass

Chemical abrasion was carried out on zircons grains of the Temora II standard for U-Pb dating prior to analyses using in situ Laser Ablation-MultiCollector Ion Coupled Plasma Mass Spectrometer (LA-ICPMS) followed by the Isotope Dissolution Thermal Ionization Mass Spectrometer (ID-TIMS) method. The proposed methodology was herein applied in order to reduce primarily the effects of secondary Pb loss, the presence of common lead and/or silicate impurities. Nine Temora II zircon grains were analyzed by the laser ablation method yielding an age of 418.3±4.3 Ma. Zircon grains of a same population were separated for chemical abrasion before dissolution and mass spectrometry analyses. Six fractions of them were separated for isotope dissolution using 235U-205Pb mixed spike after we have checked and assured the laboratory conditions of low blank values for total Pb of less than 2 pg/g. The obtained U-Pb zircon age by the ID-TIMS method was 415.7±1.8 Ma (error 0.43 %) based on four successful determinations. The results are consistent with the published ages for the Temora diorite (Temora I – 416.75±1.3 Ma; Temora II – 416.78±0.33 Ma) and established as 416±0.33 Ma. The technique is thus recommended for high precision U-Pb zircon analyses (error < 1 %), mainly for high resolution stratigraphic studies of Phanerozoic sequences.

Measurements of bio-signature in ancient micrometre-sized fossils with a miniature laser mass spectrometer

2020 ◽  
Author(s):  
Marek Tulej ◽  
Rustam Lukmanov ◽  
Andreas Riedo ◽  
Valentine Grimaudo ◽  
Coenraad de Koning ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Chemical Composition ◽  
Mass Spectrometer ◽  
Spatial Resolution ◽  
Ionization Mass ◽  
Camera System ◽  
Laser Mass Spectrometer ◽  
Ionisation Mass

&lt;p&gt;Searches for the past and present life on the planetary surfaces will be involving multilevel characterisation of the planetary rocks and soils within potentially habitable environments. Some up to three billion years old stromatolites or fossilised bacterial colonies are particularly interesting. They are found on the Earth and thought to be earliest life forms preserved within the terrestrial sedimentary rocks and can be a benchmark for searches of bio-relevant objects on planetary surfaces. By combining the microscope-camera system and mass analyser one can identify micro-fossilised material within the rocks by means of specific morphological details and characteristic chemical composition. We discuss the results of the studies on ancient microfossils obtained by space-born instrumentation, microscope-camera system combined with laser mass spectrometer. Both, the microscope imaging and chemical analyses can be conducted with micrometre spatial resolution. We demonstrate that the morphological record is helpful but not sufficient to identify bio-relevant material. Yet, while combined with elemental and isotope and with help depth profiling method, the compositional analysis can distinguish between abiotic and biological nature of the material. Detection of biosignature in measurements of fossilised materials with a miniature laser ablation ionisation mass analyser.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;[1] M. Tulej, A. Neubeck, M. Ivarsson, A. Riedo, M.B. Neuland, S. Meyer, P. Wurz, Chemical Composition of Micrometer-Sized Filaments in an Aragonite Host by a Miniature Laser Ablation/Ionization Mass Spectrometer, Astrobiology, 15 (2015) 669-682.&lt;/p&gt; &lt;p&gt;[2] A. Neubeck, M. Tulej, M. Ivarsson, C. Broman, A. Riedo, S. McMahon, P. Wurz, S. Bengtson, Mineralogical determination in situ of a highly heterogeneous material using a miniaturized laser ablation mass spectrometer with high spatial resolution, International Journal of Astrobiology, 15 (2016) 133-146.&lt;/p&gt; &lt;p&gt;[3] R. Wiesendanger, D. Wacey, M. Tulej, A. Neubeck, M. Ivarsson, V. Grimaudo, P. Moreno-Garcia, A. Cedeno-Lopez, A. Riedo, P. Wurz, Chemical and optical identification of micrometer-sized 1.9 billion-year-old fossils by combining a miniature laser ablation ionization mass spectrometry system with an optical microscope, Astrobiology, 18 (2018) 1071-1080.&lt;/p&gt; &lt;p&gt;[4] A. Riedo, A. Bieler, M. Neuland, M. Tulej, P. Wurz, Performance evaluation of a miniature laser ablation time-of-flight mass spectrometer designed for in situ investigations in planetary space research, Journal of Mass Spectrometry, 48 (2013) 1-15.&lt;/p&gt; &lt;p&gt;[5] M. Tulej, A. Riedo, M.B. Neuland, S. Meyer, P. Wurz, N. Thomas, V. Grimaudo, P. Moreno-Garcia, P. Broekmann, A. Neubeck, M. Ivarsson, CAMAM: A Miniature Laser Ablation Ionisation Mass Spectrometer and Microscope-Camera System for In Situ Investigation of the Composition and Morphology of Extraterrestrial Materials, Geostand Geoanal Res, 38 (2014) 441-466.&lt;/p&gt;

In-situ analysis of 1.9 Ga chert with a miniature mass spectrometer for space

2020 ◽  
Author(s):  
Rustam Lukmanov ◽  
Marek Tulej ◽  
Valentine Riedo ◽  
Niels Ligterink ◽  
Coenraad De Koning ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Chemical Composition ◽  
Mass Spectrometer ◽  
Depth Profiling ◽  
Ion Source ◽  
Mass Analyzer ◽  
Ionization Mass ◽  
Martian Surface ◽  
Mass Unit

&lt;p&gt;In-situ Mars exploration requires new promising instrumentation that will be capable of delivering highly accurate chemical information about soils and rocks present at the Martian surface. Specific attention is drawn to the instruments that are capable of identifying extinct or extant microbes within the bulk of various solid samples (Tulej et al., 2015; Westall et al., 2015; Wiesendanger et al., 2018). A miniature Laser Ablation/Ionization Mass Spectrometer (LIMS) developed at the University of Bern is among the valid candidates (Wurz et al., 2012). The size of the mass analyzer is only &amp;#216; 60 mm &amp;#215; 160 mm and thus capable of being deployed on a rover or lander platform. In this contribution, we will present data collected from a 1.88 Ga Gunflint sample using a deep UV fs laser system as ablation ion source. The gunflint chert sample contains a population of microfossils entombed in the silica matrix and was chosen as a Martian analogue. Using the high stability of the UV laser and consequent uniform ablation, we performed large-scale spectra collection (90&amp;#8217;000) in two modes - chemical imaging and depth profiling. With the current setup, we achieved a diameter of the analytical spot of ~10 &amp;#181;m for the depth profiling and ~5 &amp;#181;m for the imaging. Our results reveal that our LIMS instrument can identify the location of the microfossil lamination area as well as single microfossils by chemical means. We show how single mass unit spectral decomposition and subsequent kernel clustering reveal masses and intensity regions unique to the microfossils and inorganic host, thus providing the opportunity for automated identification of the spectra that are collected from the microfossils. We also show how transforming spectral intensities into spectral proximities can help to navigate the rich multidimensional datasets. We also address common interpretation problems in LIMS, when multiple mineralogical inclusions contribute to the output spectra acquired within the single analytical spot using &amp;#961;-networks and Principal Component Analysis (PCA). In combination with analysis of spectral proximities, this approach is particularly useful in attempts to assess the biogenicity of the putative terrestrial microfossils as well as potential Martian microfossils. Additionally, we discuss the data analysis pipeline and chemical composition of the microfossils and surrounding inorganic host in detail.&amp;#160;&lt;/p&gt; &lt;p&gt;Tulej M., Neubeck A., Ivarsson M., Riedo A., Neuland M. B., Meyer S., and Wurz P. (2015) Chemical Composition of Micrometer-Sized Filaments in an Aragonite Host by a Miniature Laser Ablation/Ionization Mass Spectrometer. Astrobiology, 15: 669-682.&lt;/p&gt; &lt;p&gt;Westall F., Foucher F., Bost N., Bertrand M., Loizeau D., Vago J. L., Kminek G., Gaboyer F., Campbell K. A., Br&amp;#233;h&amp;#233;ret J.-G. and others. (2015) Biosignatures on Mars: What, Where, and How? Implications for the Search for Martian Life. Astrobiology, 15: 998-1029.&lt;/p&gt; &lt;p&gt;Wiesendanger R., Wacey D., Tulej M., Neubeck A., Ivarsson M., Grimaudo V., Moreno-Garc&amp;#237;a P., Cede&amp;#241;o-L&amp;#243;pez A., Riedo A., Wurz P. and others. (2018) Chemical and Optical Identification of Micrometer-Sized 1.9 Billion-Year-Old Fossils by Combining a Miniature Laser Ablation Ionization Mass Spectrometry System with an Optical Microscope. Astrobiology, 18: 1071-1080.&lt;/p&gt; &lt;p&gt;Wurz P., Abplanalp D., Tulej M., Iakovleva M., Fernandes V. A., Chumikov A., and Managadze G. G. (2012) Mass spectrometric analysis in planetary science: Investigation of the surface and the atmosphere. Solar System Research, 46: 408-422.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt;

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