Joshua Davies | Geotop

Université du Québec à Montréal

Département des sciences de la Terre et de l'atmosphère

davies.joshua [at] uqam.ca (davies[dot]joshua[at]uqam[dot]ca)

Thèmes de recherche
Publications
Étudiants

I am a geochemist that specializes in the use of U-Pb geochronology to understand how the earth and its biosphere have evolved over time. I am particularly interested in developing new methods for generating highly precise and accurate ages and then applying these age constraints to a range of geological problems. I have recently been interested in understanding the causes of mass extinctions and determining the link between these biotic crisis and the eruption and emplacement of large igneous provinces. This link can only be determined through understanding the precise and absolute chronology of the events in geological time. Associated with this problem is the inherent difficulty in dating mafic igneous rocks which are the most important component of large igneous provinces.
I’m also interested in developing precise chronologies of events in the stratigraphic record to help understand the evolution of the near surface environment. The events I’m interested in range from cyclic sedimentary variations in Paleoproterozoic rocks which we can use to understand the climate on earth billions of years ago, to understanding changes that lead to the development of snowball earth. The approaches we take to understand these events inevitably involves radiochronologic techniques, but more and more frequently we are combining these with cyclostratigraphy and Bayesian modelling to improve our understanding of the geological record.

My research is both lab based and field based. In the lab, my group uses ultra clean environments and the EARTHTIME spikes to separate U and Pb from minute minerals and measure their isotopic compositions at high precision and generate precise and accurate ages. We also use lasers and ICP-MS mass spectrometers to quickly collect age and isotope (usually U-Pb + Hf) data from a range of minerals. We are also particularly keen on developing new analytical techniques. The field work we conduct is often in remote locations on all corners of the planet, and the samples we collect and questions we investigate allow a large range of collaborations with numerous international groups.

Accès libre Lockie, J., Ielpi, A., Canam, R., Perrot, M. G., Davies, J. H., Ootes, L., 2025. Orogenic unroofing of the Taltson and Thelon orogens depicted through detrital zircon geochronology of the Sosan Group, Great Slave Lake Supergroup (Northwest Territories, Canada). Precambrian Research 419, 107706. Données / Data

Accès libre Lockie, J., Ielpi, A., Pehrsson, S. J., Davies, J. H., Fischer, B. J., 2025. Detrital zircon geochronology of the Paleoproterozoic Nonacho Basin (Northwest Territories, Canada): A record of post-collisional collapse amid supercontinent aggregation. Precambrian Research 420, 107731. Données / Data - Données 2 / Data 2

Buryak, S. D., Reyes, A. V., West, C. K., Jensen, B. J., DuFrane, S. A., Davies, J. H. et al., 2024. Tephra zircon U-Pb geochronology of kimberlite maar sedimentary fills in subarctic Canada: Implications for Eocene paleoclimate and Late Cretaceous paleogeography. Geological Society of America Bulletin 136(9-10), 3921–3938.

Boscaini, A., Davies, J. H., Perrot, M. G., Sassi, R., Mazzoli, C. et al., 2025. Early Permian post-collisional magmatism induced by extensive removal of the Variscan lithospheric mantle. Contributions to Mineralogy and Petrology 180(2), 10.

Accès libre Condon, D., Schoene, B., Schmitz, M., Schaltegger, U., Ickert, R.B., Amelin, Y., Augland, L.E., Chamberlain, K.R., Coleman, D.S., Connelly, J.N., Corfu, F., Crowley, J.L., Davies, J.F.H.L. et al., 2024. Recommendations for the reporting and interpretation of isotope dilution U-Pb geochronological information. GSA Bulletin 136(9-10), 4233–4251.

Çörtük, R. M., Çelik, Ö. F., Özkan, M., Davies, J.H.F.L., Marzoli, A., 2024. Timing of the subduction initiation and ophiolite emplacement of the inner Tauride Ocean: Insight from the Pınarbaşı ophiolite in Central Türkiye. Lithos 488-489, 107833.

Çörtük, R. M., Çelik, Ö. F., Özkan, M., Davies, J. H., Marzoli, A., Sherlock, S. C., Halton, A. M., 2025. Emplacement history of the Central Anatolian Ophiolites: insights from the Felahiye Ophiolite in Central Türkiye. International Geology Review 67(9), 1251-1273.

Accès libre Cutts, J. A., Dyck, B. V., Perrot, M. G., Davies, J. H. F. L., Osinchuk, A. M., Šilerová, D. et al., 2024. A contiguous Taltson‐Thelon margin revisited. Geochemistry, Geophysics, Geosystems 25(7), e2024GC011527. Données / Data

Accès libre Ferraq, M., Belkacim, S., Cheng, L. Z., Davies, J. H., Perrot, M. G., Ben-Tami, A., Bouabdellah, M., 2024. New Geochemical and Geochronological Constraints on the Genesis of the Imourkhssen Cu±Mo±Au±Ag Porphyry Deposit (Ouzellagh-Siroua Salient, Anti-Atlas, Morocco): Geodynamic and Metallogenic Implications. Minerals 14(8), 832.

Miloski, P., Dare, S., Morisset, C. E., Davies, J. H., Perrot, M. G., Savard, D., 2024. Petrogenesis of Fe-Ti-P mineral deposits associated with Proterozoic anorthosite massifs in the Grenville Province: insights from oxide and apatite trace-element geochemistry at Lac à l’Orignal, Quebec, Canada. Mineralium Deposita 59, 519-556.

Miloski, P., Dare, S., Morisset, C. E., Davies, J. H., Perrot, M. G., Savard, D., 2024. Correction to: Petrogenesis of Fe‑Ti‑P mineral deposits associated with Proterozoic anorthosite massifs in the Grenville Province: insights from oxide and apatite trace‑element geochemistry at Lac à l’Orignal, Quebec, Canada. Mineralium Deposita 59, 557.

Accès libre Pinon, H., Davies, J., Tremblay, A., Perrot, M. G., 2024. Caractérisation stratigraphique et chimique de la Plateforme du Saint Laurent et des K-bentonites ordoviciennes dans la région de Montréal: implications géotechniques et géologiques. Ministère des Ressources naturelles et des Forêts, Québec, MB 2024-09.

Accès libre Popov, D., Spikings, R., Paul, A. N., Ovtcharova, M., Chiaradia, M., Kutzschbach, M. et al. (incl. J. Davies), 2024. Excess 40Ar in Alkali Feldspar and 206,207 Pb in Apatite Caused by Fluid-Induced Recrystallisation in a Semi-Closed Environment in Proterozoic (Meta) Granites of the Mt Isa Inlier, NE Australia. Geosciences 14(12), 358. Données / Data

Thiessen, E. J., Davies, J. H., Dyck, B., Perrot, M. G., Martel, E., 2024. Detrital zircon U-Pb+ Hf data supports 2.1 Ga extensional and 2.0 Ga syn-orogenic basin in southwest Rae Province during early Nuna assembly. Precambrian Research 410, 107455. Données / Data

Zhang, Q., Timmerman, S., Stachel, T., Chinn, I., Stern, R. A., Davies, J. et al., 2024. Sublithospheric diamonds extend Paleoproterozoic record of cold deep subduction into the lower mantle. Earth and Planetary Science Letters 634, 118675.

Accès libre Bond, D., Callegaro, S., Davies, J., Deegan, F., Galloway, J., Gaynor, S., Grasby, S., Jones, M., Lindström, S., Macdonald, F., Mather, T., Schaltegger, U., Svensen, H.H., Swanson-Hysell, N., 2023. Meet the Authors. Elements 19(5), 265-266.

Çelik, Ö. F., Çörtük, R. M., Özkan, M., Davies, J. H., Marzoli, A., Sherlock, S. C., Risplendente, A., Halton, A. M., Perrot, M. G., 2023. New evidence for the presence of the Inner Tauride Ocean: Lithological, geochronological and PT correlations with the Tavşanlı and Afyon zones of Central Anatolia (Türkiye). Lithos 462, 107409.

Dai, X., Davies, J. H., Yuan, Z., Brayard, A., Ovtcharova, M., Xu, G. et al., 2023. A Mesozoic fossil lagerstätte from 250.8 million years ago shows a modern-type marine ecosystem. Science 379(6632), 567-572.

Accès libre Deegan, F. M., Callegaro, S., Davies, J. H., Svensen, H. H., 2023. Driving global change one LIP at a time. Elements 19(5), 269-275.

Dufour, F., Davies, J. H., Greenman, J. W., Skulski, T., Halverson, G. P., Stevenson, R., 2023. New U-Pb CA-ID TIMS zircon ages implicate the Franklin LIP as the proximal trigger for the Sturtian Snowball Earth event. Earth and Planetary Science Letters 618, 118259.

Accès libre Gaynor, S. P., Davies, J. H., Schaltegger, U., 2023. High-precision geochronology of LIP intrusions: records of magma–sediment interaction. Elements 19(5), 302-308.

Accès libre Lantink, M. L., Lenstra, W. K., Davies, J. H., Hennekam, R., Martin, D. M., et al., 2023. Precessional pacing of early Proterozoic redox cycles. Earth and Planetary Science Letters 610, 118117.

Accès libre Reimink, J. R., Davies, J. H. F. L., Moyen, J. F., Pearson, D. G., 2023. A whole-lithosphere view of continental growth. Geochemical Perspectives Letters 26, 45-49.

Accès libre Rocha, B. C., Gaynor, S. P., Janasi, V. A., Davies, J. H., Florisbal, L. M., Waichel, B. L., Schaltegger, U., 2023. New U-Pb baddeleyite ID-TIMS ages from the intrusive high-Ti-Sr rocks of the Southern Paraná LIP, Brazil: Implications for correlations with environmental disturbances during the Early Cretaceous. Results in Geochemistry 10, 100023.

Accès libre Senger, M. H., Davies, J. H. F. L., Ovtcharova, M., Beukes, N., Gumsley, A. et al., 2023. Improving the chronostratigraphic framework of the Transvaal Supergroup (South Africa) through in-situ and high-precision U-Pb geochronology. Precambrian Research 392, 107070.

Accès libre Spiering, B. R., Bissick, A., Darroch, S. A., Davies, J. H., Gibson, B. M., Halverson, G. P. et al., 2023. Initial cyclostratigraphy of the middle Nama Group (Schwarzrand Subgroup) in southern Namibia. Precambrian Research 397, 107200.

Buryak, S. D., Reyes, A. V., Jensen, B. J., Davies, J. H., Westgate, J. A., DuFrane, S. A. et al., 2022. Laser-ablation ICP-MS zircon U-Pb ages for key Pliocene-Pleistocene tephra beds in unglaciated Yukon and Alaska. Quaternary Geochronology 73, 101398.

Accès libre Halverson, G.P., Shen, C., Davies, J.H.F.L., Wu, L., 2022. A Bayesian Approach to Inferring Depositional Ages Applied to a Late Tonian Reference Section in Svalbard. Frontiers in Earth Science 10, 798739.

Accès libre Lantink, M. L., Davies, J. H., Ovtcharova, M., Hilgen, F. J., 2022. Milankovitch cycles in banded iron formations constrain the Earth–Moon system 2.46 billion years ago. Proceedings of the National Academy of Sciences 119(40), e2117146119.

Accès libre Papapavlou, K., Moukhsil, A., Poirier, A., Davies, J., 2022. The Pre-Grenvillian assembly of the southeastern Laurentian margin through the U–Pb–Hf detrital zircon record of Mesoproterozoic supracrustal sequences (Central Grenville Province, Quebec, Canada). Geological Magazine 159(2), 199-211.

Shen, C., Schmitz, M., Johnson, P., Davies, J.H., Halverson, G.P., 2022. U-Pb geochronology and cyclostratigraphy of the middle Ediacaran upper Jibalah Group, eastern Arabian Shield. Precambrian Research 375, 106674.

Accès libre Curry, A., Gaynor, S.P., Davies, J.H.F.L., Ovtcharova, M., Simpson, G., Caricchi, L., 2021. Timescales and thermal evolution of large silicic magma reservoirs during an ignimbrite flare-up: perspectives from zircon. Contributions to Mineralogy and Petrology 176(12), 103.

Accès libre Davies, J.H.F.L., Marzoli, A., Bertrand, H., Youbi, N., Ernesto, M., Greber, N.D., Ackerson, M., Simpson, G., Bouvier, A.S., Baumgartner, L., Pettke, T., 2021. Zircon petrochronology in large igneous provinces reveals upper crustal contamination processes: new U–Pb ages, Hf and O isotopes, and trace elements from the Central Atlantic magmatic province (CAMP). Contributions to Mineralogy and Petrology 176(1), 1-24.

Boscaini, A., Marzoli, A., Davies, J. F., Chiaradia, M., Bertrand, H., Zanetti, A. et al., 2020. Permian post-collisional basic magmatism from Corsica to the Southeastern Alps. Lithos 376, 105733.

Accès libre Domeier, M., Font, E., Youbi, N., Davies, J., Nemkin, S., Van der Voo, R., Perrot, M., Benabbou, M., Boumehdi, M.A., Torsvik, T.H., 2021. On the Early Permian shape of Pangea from paleomagnetism at its core. Gondwana Research 90, 171-198.

Accès libre Heerwagen, E., Davies, J.H., Schmidt, S.T., Ulianov, A., Martini, R., 2021. The paleoposition of the Antimonio depositional system (Sonora, Mexico): New insights from nonparametric and multivariate analysis of detrital zircon data. Journal of South American Earth Sciences 105, 102913.

Accès libre Lindström, S., Callegaro, S., Davies, J., Tegner, C., van de Schootbrugge, B., Pedersen, G.K., Youbi, N., Sanei, H., Marzoli, A., 2021. Tracing volcanic emissions from the Central Atlantic Magmatic Province in the sedimentary record. Earth-Science Reviews 212, 103444.

Reimink, J.R., Davies, J.H., Ielpi, A., 2021. Global zircon analysis records a gradual rise of continental crust throughout the Neoarchean. Earth and Planetary Science Letters 554, 116654.

Accès libre Schaltegger, U., Ovtcharova, M., Gaynor, S.P., Schoene, B., Wotzlaw, J.F., Davies, J.H., Farina, F., Greber, N., Szymanowski, D., Chelle-Michou, C., 2021. Long-term repeatability and interlaboratory reproducibility of high-precision ID-TIMS U-Pb geochronology. Journal of Analytical Atomic Spectrometry 36, 1466-1477.

Accès libre Da Silva, A. C., Sinnesael, M., Claeys, P., Davies, J. H. et al., 2020. Anchoring the Late Devonian mass extinction in absolute time by integrating climatic controls and radio-isotopic dating. Scientific Reports 10(1), 12940.

Accès libre Greber, N.D., Davies, J.H., Gaynor, S., Jourdan, F., Bertrand, H., Schaltegger, U., 2020. New high precision U-Pb ages and Hf isotope data from the Karoo large igneous province; implications for pulsed magmatism and early Toarcian environmental perturbations. Results in Geochemistry 1, 100005.

Accès libre Pohlner, J.E., Schmitt, A.K., Chamberlain, K.R., Davies, J.H., Hildenbrand, A., Austermann, G., 2020. Multimethod U–Pb baddeleyite dating: insights from the Spread Eagle Intrusive Complex and Cape St. Mary's sills, Newfoundland, Canada. Geochronology 2(2), 187-208.

Accès libre Popov, D. V., Spikings, R. A., Scaillet, S., O'Sullivan, G., Chew, D., Badenszki, E. et al. (incl. J. Davies), 2020. Diffusion and fluid interaction in Itrongay pegmatite (Madagascar): Evidence from in situ 40Ar/39Ar dating of gem-quality alkali feldspar and UPb dating of protogenetic apatite inclusions. Chemical Geology 556, 119841.

Reimink, J.R., Davies, J.H., Bauer, A.M., Chacko, T., 2020. A comparison between zircons from the Acasta Gneiss Complex and the Jack Hills region. Earth and Planetary Science Letters 531, 115975.

Accès libre Rocha, B.C., Davies, J.H., Janasi, V.A., Schaltegger, U., Nardy, A.J., Greber, N.D., Lucchetti, A.C.F., Polo, L.A., 2020. Rapid eruption of silicic magmas from the Paraná magmatic province (Brazil) did not trigger the Valanginian event. Geology 48(12), 1174–1178.

Lantink, M.L., Davies, J.H.F.L., Mason, P.R.D., Schaltegger, U., Hilgen, F.J., 2019. Climate control on banded iron formations linked to orbital eccentricity. Nature Geoscience 12(5), 369-374.

Widmann, P., Davies, J.H.F.L., Schaltegger, U., 2019. Calibrating chemical abrasion: Its effects on zircon crystal structure, chemical composition and U–Pb age. Chemical Geology 511, 1-10.

Percival, L.M.E., Davies, J.H.F.L., Schaltegger, U., De Vleeschouwer, D., Da Silva, A.-C., Föllmi, K.B., 2018. Precisely dating the Frasnian-Famennian boundary: Implications for the cause of the Late Devonian mass extinction. Scientific Reports 8(1), art. no. 9578.

Davies, J.H.F.L., Sheldrake, T.E., Reimink, J.R., Wotzlaw, J.-F., Moeck, C., Finlay, A., 2018. Investigating Complex Isochron Data Using Mixture Models. Geochemistry, Geophysics, Geosystems 19(10), 4035-4047.

Farina, F., Dini, A., Ovtcharova, M., Davies, J.H.F.L., Greber, N.D., Bouvier, A.-S., Baumgartner, L., Ulianov, A., Schaltegger, U., 2018. Zircon petrochronology reveals the timescale and mechanism of anatectic magma formation. Earth and Planetary Science Letters 495, 213-223.

Schaltegger, U., Davies, J.H.F.L., 2018. Petrochronology of zircon and baddeleyite in igneous rocks: Reconstructing magmatic processes at high temporal resolution. Petrochronology: Methods and Applications, 297-328.

Davies, J.H.F.L., Stern, R.A., Heaman, L.M., Moser, D.E., Walton, E.L., Vennemann, T., 2018. Evaluating baddeleyite oxygen isotope analysis by secondary ion mass spectrometry (SIMS). Chemical Geology 479, 113-122.

Callegaro, S., Marzoli, A., Bertrand, H., Blichert-Toft, J., Reisberg, L., Cavazzini, G., Jourdan, F., Davies, J.H.F.L., Parisio, L., Bouchet, R., Paul, A., Schaltegger, U., Chiaradia, M., 2017. Geochemical constraints provided by the Freetown Layered Complex (Sierra Leone) on the origin of high-ti tholeiitic CAMP magmas. Journal of Petrology 58(9), 1811-1840.

Davies, J.H.F.L., Marzoli, A., Bertrand, H., Youbi, N., Ernesto, M., Schaltegger, U., 2017. End-Triassic mass extinction started by intrusive CAMP activity. Nature Communications 8, art. no. 15596.

Marzoli, A., Davies, J.H.F.L., Youbi, N., Merle, R., Dal Corso, J., Dunkley, D.J., Fioretti, A.M., Bellieni, G., Medina, F., Wotzlaw, J.-F., McHone, G., Font, E., Bensalah, M.K., 2017. Proterozoic to Mesozoic evolution of North-West Africa and Peri-Gondwana microplates: Detrital zircon ages from Morocco and Canada. Lithos 278-281, 229-239.

Reimink, J.R., Davies, J.H.F.L., Chacko, T., Stern, R.A., Heaman, L.M., Sarkar, C., Schaltegger, U., Creaser, R.A., Pearson, D.G., 2016. No evidence for Hadean continental crust within Earth's oldest evolved rock unit. Nature Geoscience 9(10), 777-780.

D'Abzac, F.-X., Davies, J.H.F.L., Wotzlaw, J.-F., Schaltegger, U., 2016. Hf isotope analysis of small zircon and baddeleyite grains by conventional Multi Collector-Inductively Coupled Plasma-Mass Spectrometry. Chemical Geology 433, 12-23.

Reimink, J.R., Davies, J.H.F.L., Waldron, J.W.F., Rojas, X., 2016. Dealing with discordance: A novel approach for analysing U–Pb detrital zircon datasets. Journal of the Geological Society 173(4), 577-585.

Davies, J.H.F.L., Stern, R.A., Heaman, L.M., Rojas, X., Walton, E.L., 2015. Resolving oxygen isotopic disturbance in zircon: A case study from the low δ18O Scourie dikes, NW Scotland. American Mineralogist 100(8-9), 1952-1966.

Davies, J.H.F.L., Heaman, L.M., 2014. New U-Pb baddeleyite and zircon ages for the Scourie dyke swarm: A long-lived large igneous province with implications for the Paleoproterozoic evolution of NW Scotland. Precambrian Research 249, 180-198.

Davies, J.H.F.L., Wotzlaw, J.-F., Wolfe, A.P., Heaman, L.M., 2014. Assessing the age of the Late Cretaceous Danek Bonebed with U–Pb geochronology. Canadian Journal of Earth Sciences 51(11), 982-986.

Hughes, H.S.R., McDonald, I., Goodenough, K.M., Ciborowski, T.J.R., Kerr, A.C., Davies, J.H.F.L., Selby, D., 2014. Enriched lithospheric mantle keel below the Scottish margin of the North Atlantic Craton: Evidence from the Palaeoproterozoic Scourie Dyke Swarm and mantle xenoliths. Precambrian Research 250, 97-126.

Bissick, Ajani : Doctorat en sciences de la Terre et des planètes
Department of Earth and Planetary Sciences, McGill
Codirection : Galen Halverson
Sujet de recherche : Sequence stratigraphy of late Ediacaran Minankovitch cycles, Nama Group, Namibia.

Blanchet-Gavouyère, Thomas : Maîtrise en sciences de la Terre
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal
Sujet de recherche : Étude du système U-Pb de la baddeleyite (ZrO2) appliquée aux collines montérégiennes au Québec.

Boscaini, Andrea : Stage postdoctoral
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal
Codirection : Galen Halverson
Sujet de recherche : Latest Neoproterozoic Milankovitch in the prelude to the Cambrian explosion of life (NEOMI): Basin-wide correlation of Ediacarian-Cambrian ashes combining high-precision zircon U-Pb geochronology and apatite composition

Chatila-Amos, Tania : Maîtrise en sciences de la Terre
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal
Codirection : Galen Halverson
Sujet de recherche : Géochronologie des bassins sédimentaires du paléoprotérozoïque en Australie et en Afrique du Sud afin de comprendre les corrélations entre ces bassins et l'activité magmatique dans leur région

dos Santos Jr., Angelo : Doctorat en sciences de la Terre et des planètes
Department of Earth and Planetary Sciences, McGill
Codirection : Galen Halverson
Sujet de recherche : The late Paleoproterozoic to early Mesoproterozoic Birindudu Basin (Northern Territory, Australia): Correlations with the McArthur Basin and Tectonic Implications for the development of intracratonic basins.

Geliot, Mathieu : Doctorat en sciences de la Terre et de l'atmosphère
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal
Codirection : Stéphane De Souza; Michel Jébrak
Sujet de recherche : Mise en place et genèse du champ de pegmatites Sirmac-Clapier, ceinture de roches vertes Frotet-Evans, Province du Supérieur

Musajo, Claire : Doctorat en sciences de la Terre et des planètes
Department of Earth and Planetary Sciences, McGill
Codirection : Galen Halverson
Sujet de recherche : Stratigraphie séquentielle et chimiostratigraphie de la Plateforme du Saint Laurent, dans la region de Montréal

Perrot, Morgann : Stage postdoctoral
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal
Sujet de recherche : Développement de la datation U-Pb du ciment carbonaté dans les failles et application de la technique pour comprendre l'histoire structurale de la plate-forme du Saint-Laurent

Pinon, Héloïse : Doctorat en sciences de la Terre et de l'atmosphère
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal
Codirection : Alain Tremblay
Sujet de recherche : Géochronologie des bentonites de la plate-forme St-Laurent dans la région de Montréal : corrélations stratigraphiques et implications géotechniques et tectoniques.

Quénéa, Marie : Maîtrise en sciences de la Terre
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal
Codirection : Stéphane De Souza
Sujet de recherche : Géochimie de l’apatite dans les pegmatites à Li de la Baie James

Segner, Martin : Doctorat en sciences de la Terre
Codirection : U. Schaltegger, U. Geneva
Sujet de recherche : Dating the great oxidation event in South Africa.

Whitehead, Ava : Maîtrise en sciences de la Terre et des planètes
Department of Earth and Planetary Sciences, McGill
Codirection : Galen Halverson
Sujet de recherche : Late Ediacaran Microbialites of the Nama Group, Namibia