Hf isotopic compositions of the standard zircons and baddeleyites used in U-Pb geochronology

This paper describes a combined method of simultaneously measuring U-Pb and Lu-Hf isotopes as well as trace elements in Phalaborwa baddeleyite and 91500, GJ-1, TEMORA-1 and SK10-2 zircons by means of Neptune MC-ICPMS and Agilent Q-ICPMS connected to a 193 nm excimer laser ablation system. Material ablated by laser was carried in different proportions into Q-ICPMS for U-Pb isotopic and trace elemental and MC-ICPMS for Lu-Hf isotopic compositions. Experiments indicate that different proportions of ablated material for the Q-ICPMS and MC-ICPMS (6:4, 5:5 and 4:6 respectively) do not show any bias for the zircon/baddeleyite U-Pb age, Lu-Hf isotope and trace elemental compositions within analytical errors. Using 40―60 μm spot size, the obtained U-Pb ages of Phalaborwa baddeleyite, 91500, GJ-1, TEMORA and SK10-2 zircons are 2065±15 (2 σ , n =20), 1063±6 (2 σ , n =19), 613±6 (2 σ , n =20), 416±5 (2 σ , n =20) and 32.6±0.5 (2 σ , n =20) Ma, respectively. The 176 Hf/ 177 Hf ratios are 0.281231±24 (2SD, n =20), 0.282310±35 (2SD, n =19), 0.282028±34 (2SD, n =20), 0.282687±34 (2SD, n =20) and 0.282752±53 (2SD, n =20), respectively. The obtained trace elemental compositions are identical to the reference values. Therefore, this kind of technique makes it possible to simultaneously obtain the U-Pb age, Lu-Hf isotopes and trace elemental compositions of zircon and baddeleyite, which could be an important tool in solving problems in earth sciences.

In situ simultaneous determination of trace elements, U-Pb and Lu-Hf isotopes in zircon and baddeleyite

Paragenesis and U-Pb systematics of baddeleyite (ZrO2)

The mineral baddeleyite (ZrO 2 ) occurs in many terrestrial and lunar samples and some achondrite meteorites as a trace constituent that most often crystallizes in the late-stage, most chemically fractionated portions of mafic magmas together with apatite, ilmenite, ± zircon, ± zirconolite. In terrestrial mafic rocks these interstitial regions commonly contain K-feldspar, Cl-rich mica, amphibole and a small amount of quartz. In addition, baddeleyite occurs in tektites as a dissociation product of zircon during meteorite impact and as rims on mantle zircon megacrysts recovered from kimberlites. Baddeleyite is a major carrier of Hf, Ti, Fe and U and strongly fractionates Hf from Zr as it can have very high Zr/Hf (> 50)

Evaluation of the 87Rb decay constant by age comparison against the U-Pb system

Age of carbonatite and phoscorite magmatism of the Phalaborwa Complex (South Africa)

ABSTRACT Purpose The aim was to describe experiences of the reconciliation process when living with insulin treated diabetes. Methods The study has a qualitative descriptive design, based upon nineteen in- depth interviews with persons diagnosed with insulin treated diabetes, analysed using qualitative content analysis. Results The study show the reconciliation process during different time periods that appeared as domains in the interviews. The time at diagnosis showed experiences of striving for control getting insights and knowledge. It meant striving for control of life circumstance changes, supported by professionals but also from others. In Presence showed developing strategies as a tool struggling for balance in body and life and the need of evaluating relations to others. Future was sometimes avoided as this might lead to speculations about a future life with threats and uncertainty about disease complications, as well as adaption. This meant on the same time an uncertainty, as a degree of risk-taking and hope for the best. Conclusions Persons with insulin treated diabetes need to develop flexible strategies for daily life to continuously re-evaluate their planning for attaining reconciliation. A conclusion is also that these persons need to develop a flexible regime that facilitates both quality of life and medical outcomes to reach reconciliation.

https://www.tandfonline.com/doi/pdf/10.1080/17482631.2022.2090659?needAccess=true

Gaining reconciliation when living with insulin treated diabetes: a qualitative study using content analysis

People today are on a desperate quest for solutions to enormous and complex issues from climate change to a healthy environment to a sustainable future. Abundant, sometimes conflicting information feeds our anxiety on what we, as individuals, can do. Increasingly polarized culture drives us further into our siloed ways of thinking. This study juxtaposes the Earth with the philosophical concept of ontology, a field of philosophy denoting categories or how we name the things we know or believe to exist. Geoscientists see the Earth primarily through the lens of data and the messages the Earth leaves for us to decipher. However, science is but one lens that people use to see the Earth. The Earth can also be sacred. It can evoke sensory experience or be seen as a commodity or as our environment. In the end, we all deal with choices in the face of scarcity, the classical definition of economics. Geoscientists can promote the use of these collective, multiple views to spark collaborative thinking in solving the complex problems facing life on Earth. For example, the wicked problem of Climate Change involves the classic elements of earth, water, air, and fire, and, yet, geoscientists are not always part of the conversation. Even within geoscience, disciplines are siloed by individual knowledge and institutional structures and rewards. Complex relationships of earth components such as energy with strategic minerals and water, mining the sea floor with air temperature and food security, and rising sea level with fresh water, are not clear to the general public even without the added social, economic, political, and cultural realities. Acknowledging that different viewpoints exist and drive people’s worldviews will help identify the roadblocks and opportunities in working toward a sustainable, livable Earth. 

S.C. Eriksson

Papers

Age of carbonatite and phoscorite magmatism of the Phalaborwa Complex (South Africa)

Gaining reconciliation when living with insulin treated diabetes: a qualitative study using content analysis

An earth ontology: recognizing multiple perspectives for collaborative problem-solving