Annelies van Hoesel
A. van Hoesel MSc.
Department of Earth Sciences
3508 TA Utrecht
Phone: +31 30 2531409
Fax: +31 30 2537725E-mail
office: N 210
For my PhD research, entitled “Were abrupt climate and environmental change at 12.9 ka initiated by an extraterrestrial impact?” , I focus on an extraterrestrial impact at the Allerød – Younger Dryas boundary (~12,900 cal yrs BP) as proposed by Firestone et al. (2007). This impact or airburst allegedly resulted in abrupt climate cooling, large-scale wildfires megafaunal extinctions, and rapid human behavioral shifts. Evidence for this impact, coming from several sites in America and one in Belgium, originally consisted of peaks in: magnetic grains with iridium, magnetic micro-spherules, charcoal, soot, carbon spherules and glassy carbon containing nanodiamonds, and fullerenes with extraterrestrial helium. Not all of these are normally associated with impacts and although elevated iridium concentrations and hexagonal diamonds are associated with extraterrestrial impacts and meteorites, the evidence remains inconclusive, non-reproducible and/or heavily debated.
During my research I will concentrate on investigating three fractions of the Usselo Horizon in north-western Europe for possible evidence for an impact:
- The carbonaceous fraction. The carbon spherules and possibly the glass-like carbon are said to contain several forms of nanodiamond. One of those, hexagonal diamond, is thus far only known from meteorites or in relation to an extraterrestrial impact. The occurrence of charcoal yields information on the occurrence and temperature of wildfires. In addition, radiocarbon dating of charcoal particles can be used for further age control.
- The sand fraction. Shocked quartz is considered diagnostic evidence for an extraterrestrial impact. Thus far, no shocked quartz or other minerals have been reported at the Allerød – Younger Dryas boundary. However the absence of shocked quartz does not exclude the possibility of an impact, which can also occur over the ocean.
- The magnetic fraction. A peak in magnetic grains and spherules at the Younger Dryas boundary has originally been reported, but other research groups have thus far not been able to confirm these results and report the absence of any peak or (multiple) peaks at different levels. Although concentrations of spherules have been found in known impact layers, they are not considered diagnostic evidence as they can also form through different processes.
Just, A., Dekkers, M.J., Dobeneck, T. von, Hoesel, A. van, Bickert, T. (2012) Signatures and significance of aeolian, fluvial, bacterial and diagenetic magnetic mineral fractions in Late Quaternary marine sediments off Gambia, NW Africa. Geochemistry, Geophysics, Geosystems 13(9), Q0AO02, doi:10.1029/2012GC004146.
Hoesel, A. van (2012). Een meteorietinslag aan het begin van de Jonge Dryas? Geo.brief, 37(4), 10-11.
Hoesel, A. van, Hoek, W.Z., Braadbaart, F., Plicht, J. van der, Pennock, G.M. & Drury, M.R. (2012). Nanodiamonds and wildfire evidence in the Usselo horizon postdate the Allerød-Younger Dryas boundary. Proceedings of the National Academy of Sciences of the United States of America, 109(20), 7648-7653.
7. van Hoesel, A., Hoek, W.Z., Pennock, G., Drury, M.R., 2011 (poster). Diamonds in the Dutch subsurface: An EM analysis of ~13,000 year old carbonaceous material. NVvM material science meeting, November 10, Eindhoven, The Netherlands.
6. Hoek, W.Z., Kasse, C., Bohncke, S.J.P., Hoesel, A. van & Smit, J. (2011, October 7). Climate or extra-terrestrial impact? The Allerød-Younger Dryas Transition (GI-1 to GS-1) in the Netherlands. EU COST action ES0907 Workshop, Potsdam, Germany.
5. van Hoesel, A., Hoek, W.Z., Braadbaart, F., van der Plicht, J., 2011 (talk). Nanodiamonds and the Usselo layer. XVIII INQUA-Congress, July 21-17, Bern, Switzerland.
4. Hoek, W.Z., Kasse, C., Bohncke, S.J.P., van Hoesel, A., Smit, J., 2011 (poster). The Allerød-Younger Dryas Transition in lake sediments from The Netherlands. XVIII INQUA-Congress, July 21-17, Bern, Switzerland.
3. van Hoesel, A., Karssenberg, D.J., Cohen, K.M., 2011 (poster). Modelling the opening of the Dover Strait: retrograding pro-glacial lake spillage. XVIII INQUA-Congress, July 21-17, Bern, Switzerland.
2. Cohen, K.M., Busschers, F.S., Gibbard, P., Hijma, M.P., van Hoesel, A., Karssenberg, D.J., 2011 (poster). The successive roles of proglacial drainage, normal ice-age rivers and marine processes in eroding the Strait of Dover and adjacent southernmost North Sea in the last 500 ka. XVIII INQUA-Congress, July 21-17, Bern, Switzerland.
1. van Hoesel, A., Drury, M.R., Hoek, W.Z., 2010 (poster). Testing the Younger Dryas impact hypothesis. 10th Nederlans Aardwetenschappelijk Congress, April 22-23, Veldhoven, The Netherlands.
Past and present
- Since Nov. 2009: PhD student at Utrecht University
Research topic: Were abrupt climate and environmental change at 12.9 ka initiated by an extraterrestrial impact?
- jul. 2009 - oct. 2009: Junior researcher at Utrecht University department of Physical Geography.
- sep. 2007 – aug. 2009: MSc in the Earth Sciences – System Earth Modelling programme, at Utrecht University.
MSc thesis: Modelling the opening of the Dover Strait – retrograding pro- glacial lake spillage.
- sep. 2004 – aug. 2007: BSc in the Earth Sciences – Physical Geography programme, at Utrecht University