scholarly journals Combined U-Pb and Lu-Hf isotope analyses by laser ablation MC-ICP-MS: methodology and applications

2010 ◽  
Vol 82 (2) ◽  
pp. 479-491 ◽  
Author(s):  
Massimo Matteini ◽  
Elton L. Dantas ◽  
Marcio M. Pimentel ◽  
Bernhard Bühn
Keyword(s):  
Isotopic Ratio ◽  
Sediment Provenance ◽  
Significant Information ◽  
Icp Ms ◽  
Borborema Province ◽  
Isotopic Studies ◽  
The University ◽  
Isotope Analyses ◽  
Magmatic Event

The Lutetium-Hafnium isotopic system represents one of the most innovative and powerful tools for geochronology and isotopic studies. Combined U-Pb and Lu-Hf in situ analyses on zircon by LA-MC-ICP-MS permit to characterize isotopically the host magma from which it crystallized furnishing significant information for sediment provenance and crustal evolution studies. In this paper e describe the Lu-Hf systematic by LA-MC-ICP-MS developed in the laboratory of Geochronology of the University of Brasilia and report the results obtained by repeated analyses of 176Hf/177Hf isotopic ratio of three zircon standards: GJ-1 = 0.282022 ± 11 (n=56), Temora 2 = 0.282693 ± 14 (n=25) and UQZ = 0.282127 ± 33 (n=11). The 176Hf/177Hf ratio (0.282352 ± 22, n=14) of gem quality zircon used as in-house standard have been also characterized. As a geological application, we analyzed two complex zircons selected from a migmatitic rocks from the Borborema Province, NE Brazil. On the basis of U-Pb and Lu-Hf data, two main crystallization events have been identified in both studied zircons. An older event at ca. 2.05 Ga recognized in the inherited cores represents a well-characterized paleoproterozoic magmatic event that affected the whole Borborema Province. A second crystallization event at ~ 575 Ma, recognized at the rims, represents a Neoproterozoic (Brazilian) high grade metamorphic-magmatic event.

Development of sulfide reference materials for in situ platinum group elements and S–Pb isotope analyses by LA-(MC)-ICP-MS

2018 ◽  
Vol 33 (12) ◽  
pp. 2172-2183 ◽  
Author(s):  
Yantong Feng ◽  
Wen Zhang ◽  
Zhaochu Hu ◽  
Yongsheng Liu ◽  
Kang Chen ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Reference Materials ◽  
Platinum Group Elements ◽  
Pb Isotopes ◽  
Synthetic Method ◽  
Pb Isotope ◽  
Icp Ms ◽  
Platinum Group ◽  
Isotope Analyses

A new synthetic method has been used to prepare sulfide reference materials for the in situ analysis of PGEs and S–Pb isotopes. The results indicate that the hydrothermal synthesis of the nanoparticles can serve as a potentially effective approach for the preparation of microanalysis reference materials.

In situ high-precision lithium isotope analyses at low concentration levels with femtosecond-LA-MC-ICP-MS

2019 ◽  
Vol 34 (7) ◽  
pp. 1447-1458 ◽  
Author(s):  
Lena K. Steinmann ◽  
Martin Oeser ◽  
Ingo Horn ◽  
Hans-Michael Seitz ◽  
Stefan Weyer
Keyword(s):  
High Precision ◽  
Signal Intensity ◽  
Lithium Isotope ◽  
Single Measurement ◽  
Low Concentration ◽  
Icp Ms ◽  
Isotope Analyses ◽  
Concentration Levels

Precision of a single measurement in the low signal intensity area is better with a combination of a 1013 Ω amplifier and a SEM.

scholarly journals Geochemical trends in weathering profiles and their underlying Precambrian basement rocks in Akure, Southwestern Nigeria

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Oluwatoyin O. Akinola ◽  
Olusola A. OlaOlorun
Keyword(s):  
Residual Soils ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
Basement Rocks ◽  
Icp Ms ◽  
Analytical Result ◽  
The University ◽  
Plastic Clays ◽  
In Situ Weathering

Akure area in southwestern Nigeria falls within the basement complex underlain by migmatite, quartzite granite and charnockite. Geochemical features of these crystalline rocks and their overlying in-situ weathering profiles are investigated and reported. Analytical result from ICP-MS facility at the University of Malaya reveals average SiO2 content in quartzite (91.1%), granite (73.8%), migmatite (67.4%) and charnockite (58.6%) categorize the rocks as siliceous. SiO2 contents in the weathering profiles above these rocks are 61.9%, 60.2%, 52.2% and 54.6% respectively. Alumina contents in the weathering profiles overlying quartzite (23.8%), granite (19.9%), migmatite (26.3%) and charnockite (24.3%) are substantially higher than the precursor rocks. In the same order, average alkali (Na2O+K2O) contents in the profiles are 3.38%, 3.42%, 3.48% and 2.68%. Chemical features of the profiles reflect that there exists some correlation between the chemistry of crystalline basement and their in-situ weathering profiles. The residual soils contain low plastic clays with kaolinitic characteristics and compare well with other clays reported from other parts of Nigeria basement complex. 

Unraveling potential biases in U-Pb detrital zircon record induced by high-temperature metamorphism (> 850 ºC)

2021 ◽  
Author(s):  
Mahyra Tedeschi ◽  
Humberto Reis ◽  
Laura Stutenbecker ◽  
Matheus Kuchenbecker ◽  
Bruno Ribeiro ◽  
...  
Keyword(s):  
High Temperature ◽  
Detrital Zircon ◽  
Metamorphic Event ◽  
Sediment Provenance ◽  
Metamorphic Rocks ◽  
Zircon Age ◽  
Icp Ms ◽  
Depositional Age ◽  
High Temperature Metamorphism

<p>Detrital zircon records are prone to several sources of bias that can compromise sediment provenance investigations based on U-Pb ages. High-temperature metamorphism (>850 ºC) is herewith addressed as a natural cause of bias since U-Pb zircon data from rocks submitted to these extreme, often prolonged conditions, frequently display protracted apparent concordant geochronological U-Pb records. The resulting spectrum can originate from disturbance of the primary U-Pb zircon system, likewise from subsequent recrystallization and crystallization processes during multiple and/or prolonged metamorphic events. Consequently, a high-grade metamorphosed igneous rock can exhibit a zircon age spectrum similar to that produced by polymict sedimentary rocks, thereby inducing provenance misinterpretations if this rock becomes a source for a sediment. A polymict sedimentary source that undergoes such high temperatures could potentially generate an even more intricate spectrum. Archean, Neoproterozoic and Paleozoic metamorphic rocks from the literature, dated by different techniques (SIMS and LA-ICP-MS), are employed as examples to demonstrate the resulting complications.  The compilation shows that (1) high-temperature metamorphism may generate age peaks of unclear or lacking geological meaning, and (2) the interpretation of detrital zircon age spectra depends on the timing of the metamorphic event (pre- or post-depositional). When high-temperature metamorphic rocks are eroded in uplifted areas, the youngest population of a detrital spectrum represents the maximum depositional age through metamorphic zircon from the source. If a sedimentary succession was subjected to high-temperature metamorphic conditions after deposition, its youngest zircon population more likely records the metamorphism, and the maximum depositional age, as well as older sources cannot be directly accessed. To evaluate the presence of high-temperature metamorphism-related bias in a given detrital zircon sample, we suggest a workflow for data acquisition and interpretation, combining a multi-proxy approach with: in situ U-Pb dating coupled with Hf analyses to retrieve the isotopic composition of the sources, and the integration of a petrochronological investigation to typify fingerprints of the (ultra)high-temperature metamorphic event.</p>

scholarly journals In situ Sr isotope analyses by LA-MC-ICP-MS of igneous apatite and plagioclase from magmatic rocks at the CPGeo-USP

2016 ◽  
Vol 46 (suppl 1) ◽  
pp. 227-243
Author(s):  
Patricio Montecinos Munoz ◽  
Adriana Alves ◽  
Rogério Guitarrari Azzone ◽  
Pablo Cordenons ◽  
Sandra Morano ◽  
...  
Keyword(s):  
Magma Mixing ◽  
Successful Implementation ◽  
Geochemical Processes ◽  
Sr Isotope ◽  
Magmatic Rocks ◽  
Icp Ms ◽  
Isotope Analyses ◽  
Better Than

ABSTRACT: This contribution describes the successful implementation of in situ Sr isotope analyses by LA-MC-ICP-MS at the CPGeo-USP. The choice for an analytical configuration using measurements of half-masses allows the accurate assessment of lanthanide interferences, permitting the determination of Sr isotopes in important REE-rich accessory phases, such as apatite. Likewise, the on-peak-zero method effectively corrects the background contribution (both from Kr and residual Sr contributions from previous ablations) to the signals of the unknown samples. The analytical campaigns resulted in an accuracy, in respect to reference TIMS values, better than 57 ppm (~ ±0.000057 2σ SD) for a modern coral and the Batjberg clinopyroxene which impart significant quality to our data. Similarly, the majority of the stable Sr isotope ratios are close to the accepted values, which also confirms the effectiveness of the method. The achieved accuracy allows the identification and investigation of spatially-controlled isotopic heterogeneities on the micrometric scale in several Sr-rich minerals (apatite, carbonates, plagioclase, and clinopyroxene) with important implications to the understanding of relevant geochemical processes, particularly AFC, source geochemical heterogeneities and magma-mixing.

Improved in situ Li isotopic ratio analysis of silicates by optimizing signal intensity, isotopic ratio stability and intensity matching using ns-LA-MC-ICP-MS

2017 ◽  
Vol 32 (4) ◽  
pp. 834-842 ◽  
Author(s):  
Jie Lin ◽  
Yongsheng Liu ◽  
Xirun Tong ◽  
Lvyun Zhu ◽  
Wen Zhang ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Isotopic Ratio ◽  
Silicate Glasses ◽  
Isotopic Ratios ◽  
Ratio Analysis ◽  
Icp Ms

How to get accurate and precise in situ Li isotopic ratios of silicate glasses on a ns-LA-MC-ICP-MS (Neptune Plus).

Precise magnesium isotope analyses of high-K and low-Mg rocks by MC-ICP-MS

2019 ◽  
Vol 34 (5) ◽  
pp. 940-953 ◽  
Author(s):  
Zhian Bao ◽  
Kangjun Huang ◽  
Tianzheng Huang ◽  
Bing Shen ◽  
Chunlei Zong ◽  
...  
Keyword(s):  
Igneous Rock ◽  
Magnesium Isotope ◽  
Rock Samples ◽  
High K ◽  
Icp Ms ◽  
Isotope Analyses

This study presents a chemical protocol for the separation of Mg that is particularly adapted for diverse igneous rock samples, especially for high-K and low-Mg rocks.

In situ Fe isotopic analyses of fourteen reference materials using a synthetic Cr standard for mass bias and isobaric interference corrections by femtosecond LA-MC-ICP-MS

2021 ◽  
Author(s):  
Lei Xu ◽  
Wen Zhang ◽  
Tao Luo ◽  
Jin-Hui Yang ◽  
Zhaochu Hu
Keyword(s):  
Reference Materials ◽  
Isotope Ratios ◽  
Isobaric Interference ◽  
Analytical Technique ◽  
Mass Bias ◽  
Icp Ms ◽  
Isotopic Analyses

High precise and accurate measurements of Fe isotope ratios for fourteen reference materials from the USGS, MPI-DING and CGSG were successfully carried out using a developed analytical technique by fs...

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