A5024328617- Planetary Science and Exploration
- Astro and Planetary Science
- Geological and Geochemical Analysis
- Space Exploration and Technology
- Geology and Paleoclimatology Research
- High-pressure geophysics and materials
- earthquake and tectonic studies
- Isotope Analysis in Ecology
- Radioactive element chemistry and processing
- Geochemistry and Geologic Mapping
- Paleontology and Stratigraphy of Fossils
- Mineralogy and Gemology Studies
- Minerals Flotation and Separation Techniques
- Dental Radiography and Imaging
- Nuclear Physics and Applications
- Iron oxide chemistry and applications
- Earthquake Detection and Analysis
- X-ray Spectroscopy and Fluorescence Analysis
- Geological and Geophysical Studies
- Metal Extraction and Bioleaching
- Smart Systems and Machine Learning
- activated carbon and charcoal
- Structural Response to Dynamic Loads
- Geochemistry and Elemental Analysis
- Geomagnetism and Paleomagnetism Studies
Swedish Museum of Natural History
2017-2025
Boise State University
2021
Trinity College Dublin
2015-2019
22q11 Ireland
2017
Lunar meteorites provide a potential opportunity to expand the study of ancient (>4000 Ma) basaltic volcanism on Moon, which there are only few examples in Apollo sample collection. Secondary Ion Mass Spectrometry (SIMS) was used determine Pb isotopic compositions multiple mineral phases (Ca-phosphates, baddeleyite K-feldspar, K-rich glass and plagioclase) two lunar meteorites, Miller Range (MIL) 13317 Kalahari (Kal) 009. These data were calculate crystallisation ages 4332±2 Ma (95%...
Abstract U–Pb geochronology of shocked monazite can be used to date hypervelocity impact events. Impact-induced recrystallisation and formation mechanical twins in have been shown result radiogenic Pb loss thus constrain ages. However, little is known about the effect porosity on system monazite. Here we investigate two melt rocks from Hiawatha structure, Greenland by means nano- micrometre-scale techniques. Microstructural characterisation scanning electron transmission microscopy imaging...
Abstract Morphological studies of large impact structures on Mercury, Venus, Mars, and the Moon suggest that volcanism within craters may not be confined to shock melting target rocks. This possibility prompted reinvestigation 1.85 Ga subaqueous Sudbury structure, specifically its 1.5 km thick immediate basin fill (Onaping Formation). Historically, breccias this formation were debated in context an endogenic versus impact‐fallback origin. New field, petrographic, situ geochemical data...
Pockets of Ediacaran–Cambrian clastic sedimentary rocks are preserved across Fennoscandia, but the provenance, depositional setting and age many such deposits remain uncertain. We report first detrital zircon provenance study lowermost sediments deposited on sub-Cambrian bedrock in southern Sweden. performed 285 ion microprobe U–Pb analyses zircons from Mickwitzia Sandstone (File Haidar Formation, Cambrian Series 2). Age peaks at c. 2100, 2000, 1800, 1550, 1500, 1225, 1150 950 Ma consistent...
Research Article| June 01, 2016 Differentiated impact melt sheets may be a potential source of Hadean detrital zircon Gavin G. Kenny; Kenny 1Department Geology, School Natural Sciences, Trinity College Dublin, Dublin 2, Ireland Search for other works by this author on: GSW Google Scholar Martin J. Whitehouse; Whitehouse 2Department Geosciences, Swedish Museum History, 104 05 Stockholm, Sweden Balz S. Kamber Geology (2016) 44 (6): 435–438. https://doi.org/10.1130/G37898.1 Article history...
Uranium-lead (U-Pb) geochronology of individual shocked zircon grains has unique potential for dating bolide impact events. Neoblasts in granular-textured have been recognized as the shock-related feature most effective at recording age. Here we report discovery large neoblasts (5–100 µm dimension) Sudbury structure, Canada—the first situ coarsely granular from a terrestrial site other than Vredefort South Africa. The neoblast-bearing sample was taken heterogeneous, lithic clast–rich igneous...
Abstract Constraining the duration of magmatic activity on Moon is essential to understand how lunar mantle evolved chemically through time. Determining age and initial isotopic compositions mafic meteorites a critical step in defining periods that occurred during history constrain chemical characteristics components involved sources magmas. We have used situ Pb‐Pb SIMS technique investigate eight gabbros basalts, including six from Northwest Africa (NWA) 773 clan (NWA 2727, NWA 2700, 3333,...
Abstract The chemical and isotopic characteristics of terrestrial basalts are constrained within the concept mantle geodynamics that explains existing variety basaltic rocks a framework several end-member reservoirs in Earth’s mantle. In contrast, there is no comparable fully developed model explaining composition lunar rocks, part owing to lack well-constrained age–isotope relationships different groups identified on Moon. Notably, absence agreement upon ages includes from unique group...
<sup>206</sup>Pb–<sup>238</sup>U LA-ICPMS image map of a complex, polyphase zircon produced using 7 micron rasters.
Abstract Despite the wide utility of apatite, Ca5(PO4)3(F,Cl,OH), in geosciences, including tracing volatile abundances on Moon and Mars, little is known about how mineral responds to extreme temperatures pressures associated with hypervelocity impacts. To address this deficiency, we here present first microstructural analysis chemical mapping shocked apatite from a terrestrial impact crater. Apatite grains Paasselkä structure, Finland, display intragrain crystal-plastic deformation as well...
Abstract Reidite, the high‐pressure zircon (ZrSiO 4 ) polymorph, is a diagnostic indicator of impact events. Natural records reidite are, however, scarce, occurring mainly as micrometer‐sized lamellae, granules, and dendrites. Here, we present unique sequence shocked grains found within clast from Chassenon suevitic breccia (shock stage III) ˜200 Ma, 20–50 km wide Rochechouart structure in France. Our study comprises detailed characterization with scanning electron microscopy coupled...
The Sudbury impact structure is one of only a few terrestrial craters capable providing insight into large processes. However, despite more than century study, no consensus exists regarding its depths excavation and melting. This study presents 3920 U–Pb zircon dates for target lithologies the crater-fill as well new Pb-isotope data in an attempt to further constrain these understand behaviour impacts. Only 1.5% zircons have within uncertainty 1.85 Ga event, with most seeming preserve their...
Abstract The Stac Fada Member of the Stoer Group, within Torridonian succession NW Scotland, is a melt-rich, impact-related deposit that has not been conclusively correlated with any known impact structure. However, gravity low approximately 50 km east preserved outcrops recently proposed as associated site. We investigate location structure through provenance study detrital zircon and apatite in five samples from Group. Our U–Pb data are dominated by Archaean grains (> 2.5 Ga),...
Abstract Hypervelocity impacts can produce features in zircon that are not normally produced by endogenic processes. However, lightning also induce extreme pressure–temperature excursions, and its effect on has been studied. With the aim to recognise form response excursions but unique hypervelocity impacts, we imaged undertook microstructural characterization of a fulgurite (a tubular body glass fused clasts formed strike). We document with granular ZrO 2 rims vermicular , which vary...
Impact cratering was a fundamental geological process in the early Solar System and, thus, constraining timescales over which large impact structures cool is critical to understanding thermal evolution and habitability of planetary crusts. Additionally, impacts can induce mass extinctions establishing precise timing largest on Earth shed light their role such events. Here we report high-precision zircon U–Pb geochronology study Morokweng structure, South Africa, appears have maximum...
The ~31-km-wide Hiawatha structure, located beneath Glacier in northwestern Greenland, has been proposed as an impact structure that may have formed after the Pleistocene inception of Greenland Ice Sheet. To date we conducted 40Ar/39Ar analyses on glaciofluvial sand and U-Pb zircon separated from pebbles melt rock, all sampled immediately downstream Glacier. Unshocked rocks dates to ~1915 million years (Ma), consistent with felsic intrusions found local bedrock. data indicate Late Paleocene...
We report a new age for the Sääksjärvi impact structure, Finland, 6 km diameter feature that formed in crystalline rocks of Precambrian Baltic Shield. Two previous studies reported 40 Ar/ 39 Ar data and suggested conflicting formation ages ≤330 Ma or c. 560 Ma. The former represents possible complication models which indicate region was covered by sediments Caledonian foreland basin throughout much Phanerozoic. conducted study combining imaging, microstructural analysis U–Pb dating shocked...
Abstract There are likely many undiscovered impact structures on Earth, but several challenges prevent their detection, including possible concealment beneath large ice sheets. In recent years, geophysical, geochemical, and microphysical evidence has mounted for a ca. 58 Ma structure under the Hiawatha Glacier, northwest Greenland. Here, we report second, much older hypervelocity event in this region, recorded an melt rock sample collected from glaciofluvial deposit Inglefield Land....