A5072633546- Astro and Planetary Science
- Planetary Science and Exploration
- Geological and Geochemical Analysis
- Advanced Materials Characterization Techniques
- High-pressure geophysics and materials
- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Geochemistry and Geologic Mapping
- Space Exploration and Technology
- Isotope Analysis in Ecology
- Space Science and Extraterrestrial Life
- Radioactive element chemistry and processing
- Origins and Evolution of Life
- Radioactivity and Radon Measurements
- Electronic and Structural Properties of Oxides
- earthquake and tectonic studies
- Metal Extraction and Bioleaching
- Geomagnetism and Paleomagnetism Studies
- Nuclear Materials and Properties
- Geochemistry and Geochronology of Asian Mineral Deposits
- Astronomical and nuclear sciences
- Mineralogy and Gemology Studies
- Hydrocarbon exploration and reservoir analysis
- Cryospheric studies and observations
- Zeolite Catalysis and Synthesis
University of Toronto
2018-2024
Royal Ontario Museum
2018-2024
University of Portsmouth
2015-2024
The Open University
2021-2024
Ministre de la Forêt,de la Mer et de l'Environnement
2021
National Agency for National Parks
2014
The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following first appreciable rise free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis metamorphism, ca. black shales Francevillian B Formation (FB2) cropping out southeastern Gabon not. contains centimeter-sized...
Abstract Resolving the timing of crustal processes and meteorite impact events is central to understanding formation, evolution habitability planetary bodies. However, identifying multi-stage from complex materials highly challenging at length scales current isotopic techniques. Here we show that accurate U-Pb analysis nanoscale domains baddeleyite can be achieved by atom probe tomography. Within individual crystals shocked Sudbury structure, three discrete nanostructural have been isolated...
The provenance of sand-sized ice-rafted debris (IRD) sourced from Greenland is currently difficult to determine. Such knowledge, if it could be ascertained with a high degree certainty, applied the Greenland-proximal marine records improve both our understanding modern-day spatial patterns iceberg rafting and past history Ice Sheet (GIS). Recent studies have highlighted utility Pb-isotope composition individual feldspars 40Ar/39Ar ages hornblendes in this regard. However, before any such...
Abstract Apatite and merrillite are the most common phosphate minerals in a wide range of planetary materials key accessory phases for situ age dating, as well determination volatile abundances their isotopic composition. Although lunar meteoritic samples show at least some evidence impact metamorphism, relatively little is known about how these two phosphates respond to shock‐loading. In this work, we analyzed set well‐studied highlands (Apollo 17 Mg‐suite rocks 76535, 76335, 72255, 78235,...
The elemental and chlorine isotope compositions of calcium-phosphate minerals are key recorders the volatile inventory Mars, as well planet's endogenous magmatic hydrothermal history. Most martian meteorites have clear evidence for exogenous impact-generated deformation metamorphism, yet effects these shock metamorphic processes on isotopic records contained within calcium phosphates not been evaluated. Here we test a single cycle systematics in apatite from highly shocked, enriched...
The quenched (rapidly-cooled) angrite meteorites, which formed in the inner Solar System, record large-scale planetary mixing first few Ma of System history, and therefore, provide a unique opportunity to investigate role impacts terms water addition growing planetesimals. Here we H isotopic composition H2O abundance relict olivine grains that survived impact melting within Asuka (A) 12,209 compare them with melt-produced groundmass fractions using in-situ nanoscale secondary ion mass...
Abstract. Baddeleyite is a powerful chronometer of mafic magmatic and meteorite impact processes. Precise accurate U–Pb ages can be determined from single grains by isotope dilution thermal ionization mass spectrometry (ID-TIMS), but this requires disaggregation the host rock for grain isolation dissolution. As result, technique rarely applied to precious samples with limited availability (such as lunar, Martian, asteroidal meteorites returned samples) or containing small baddeleyite that...
Research Article| July 12, 2018 Baddeleyite as a widespread and sensitive indicator of meteorite bombardment in planetary crusts L.F. White; White * 1School Earth Environmental Sciences, University Portsmouth, Portsmouth PO1 3QL, UK2Department Natural History, Royal Ontario Museum, 100 Queens Park, Toronto, M5S 2C6, Canada3Deparment 3B1, Canada *E-mail: lwhite@rom.on.ca Search for other works by this author on: GSW Google Scholar J.R. Darling; Darling UK D.E. Moser; Moser 4Department Western...
Abstract Impact cratering on the Moon and derived size-frequency distribution functions of lunar impact craters are used to determine ages unsampled planetary surfaces across Solar System. Radiometric dating samples provides an absolute age baseline, however, crater-chronology for remain poorly constrained beyond 3.9 billion years. Here we present U–Pb geochronology phosphate minerals within shocked norites a boulder from Apollo 17 Station 8. These record older event around 4.2 years ago,...
Spurred by the discovery of water in lunar volcanic glasses about a decade ago, accessory mineral apatite became primary target to investigate abundance and source water. This is due its ability contain significant amounts OH structure, along with widespread presence rocks. There general understanding that crustal cumulate rocks magnesian (Mg) suite are better candidates for recording original isotopic compositions volatile elements their parental melts compared eruptive rocks, such as mare...
Abstract The Mighei‐like carbonaceous (CM) chondrites have been altered to various extents by water–rock reactions on their parent asteroid(s). This aqueous processing has destroyed much of the primary mineralogy these meteorites, and degree alteration is highly heterogeneous at both macroscale nanoscale. Many CM meteorites are also heavily brecciated juxtaposing clasts with different histories. Here we present results from fine‐grained team consortium study Winchcombe meteorite, a recent...
Abstract As some of the oldest differentiated materials in our solar system, angrite meteorites can provide unique insights into earliest stages planetary evolution. However, timing mixing, as evidenced by oxygen isotope variations quenched angrites, and extent magmatism on parent body (APB) remain poorly understood. Here, we report microstructurally guided situ geochemical Pb–Pb isotopic measurements angrites aimed at better understanding nature magmatic processes, well impact events, APB....
Granulitic lunar meteorites offer rare insights into the timing and nature of igneous, metamorphic impact processes in crust. Accurately dating different events recorded by these materials is very challenging, however, due to low trace element abundances (e.g. Sm, Nd, Lu, Hf), micrometer-scale U-Th-bearing accessory minerals, disturbed Ar-Ar systematics following a multi-stage history shock thermal metamorphism. Here we report on micro-baddeleyite grains granulitic mafic breccia NWA 3163 for...
Abstract Northwest Africa ( NWA ) 6342 is an intermediate, poikilitic shergottite, found in Algeria 2010. It comprised of two distinct petrographic areas; domains with rounded Mg‐rich olivine chadacrysts enclosed by large low‐Ca pyroxene oikocrysts, and a nonpoikilitic domain mainly subhedral vesicular recrystallized plagioclase. Oxygen fugacity conditions become more oxidizing during crystallization from the to QFM −3.0 −2.2). As such, it likely that experienced two‐stage (polybaric)...
Understanding the timing and mechanisms of amino acid synthesis racemization on asteroidal parent bodies is key to demonstrating how acids evolved be mostly left-handed in living organisms Earth. It has been postulated that can occur rapidly dependent several factors, including pH aqueous solution. Here, we conduct nanoscale geochemical analysis a framboidal magnetite grain within Tagish Lake carbonaceous chondrite demonstrate interlocking crystal arrangement formed sodium-rich, alkaline...
A long-standing paradigm in planetary science is that the inner Solar System experienced a period of intense and sustained bombardment between 4.2 3.9 Ga. Evidence this period, termed Late Heavy Bombardment provided by 40Ar/39Ar isotope systematics returned Apollo samples, lunar meteorites, asteroidal meteorites. However, it has been largely unsupported more recent robust isotopic age data, such as data obtained using U-Pb system. Here we conduct careful microstructural characterisation...
Abstract Our Galaxy is vast and awe-inspiring. The stars, planets, our sun capture imagination as children. For many of us, that wonder never ceases. It continues to inspire us throughout careers prompts question the evolution Solar System, what place within it, how we may maintain longevity in a relatively volatile environment. To answer these questions planetary scientists turn study extraterrestrial material. They analyze meteorites, impact craters, materials returned by sample return...