Scientific papers

A – Peer reviewed research articles and reviews
B – Comments, brevia and perspectives
C – Editorials
D – Textbook chapters
E – Theses
P – Press releases
† – shared first-authorship, bold font: Dahl group members


A47. Zhang L, Algeo TJ, Zhao L, Dahl TW, Chen Z-Q, Zhang Z, Poulton SW, Hughes NC, Gou X, Li C. Environmental and trilobite diversity changes during the middle-late Cambrian SPICE event. GSA Bull. (Accepted, in press)

D2. Dahl TW, “Origin of O2 on Earth”, in Origins. Eds. D. Harper & O. Seeberg. Gyldendal (Accepted, in press, fall 2023)

A46. Zhao Z, Dickson A, Basu A, Nielsen AT, Pang X, Schovsbo NH, Dahl TW. Dynamic oceanic redox conditions across the late Cambrian SPICE event constrained by molybdenum and uranium isotopes. Earth and Planetary Science Letters. Available online soon


A45. Dahl TW, Harding MAR, Brugger J, Feulner G, Norrman K, and Junium CK. Low atmospheric CO2 levels before the emergence of forested ecosystems. Nature Communications 13 (1), 1-10 (2022). Link

D1. Shields GA, Edgar K, Ratcliffe KT, and Dahl TW. “Chapter 6: Chemostratigraphy” in book series published by the Geological Society of London. Editor: A. Coe. Online.

A44. del Rey Á, Rasmussen CMØ, Calner M, Planavsky N, Dahl TW. Stable ocean redox during the main phase of the Great Ordovician Biodiversification Event. Nature Comm. Earth Env. Sep 2022. Link

A43. Wang W, Zhang F, Connelly J, Bizzarro M, Shen S-Z, Dahl TW. Uranium isotopes in Permian calcitic brachiopods and marine carbonates: validation of the global paleoredox proxy and implications for ocean oxygenation in the Permian. In review at Earth and Planetary Science Letters. Link

A42. Zhao Z, Thibault N, Dahl TW, Schovsbo NH, Sørensen AL, Rasmussen CMØ, Nielsen AT, Synchronizing rock clocks in the Cambrian. Nature Comm. 13. 1-13. (2022). Link

A41. Zhang F, Stockey RG, Xiao S, Shen S-Z, Dahl TW, Cui Y, Li Z, Anbar AD, Planavsky NJ. Uranium isotope evidence for extensive shallow water anoxia in the early Tonian oceans. Earth and Planetary Science Letters, 583, (2022), 117437. Link

A40. Zhao Z, Ahlberg P, Thibault N, Dahl TW, Schovsbo N, Nielsen AT. High-resolution carbon isotope chemostratigraphy of the middle Cambrian to lowermost Ordovician in southern Scandinavia: implications for global correlation. Global and Planetary Change. 209 103751. (2022) Link


A39. Gill BC, Dahl TW, Hammarlund EU, LeRoy MA, Gordon GW, Canfield DE, Anbar AD, Lyons T. Redox dynamics of later Cambrian oceans. Palaeogeography, Palaeoclimatology, Palaeoecology. Vol 581, (2021), 110623. Link

A38. Halder S, Arens SKM, Jensen K, Dahl TW, Porada P. A dynamic local scale vegetation model lycophytes (LYCOm). Geosci. Model Dev., 15, 2325–2343, Link, 2021.

A37. Dahl TW, Hammarlund EU, Rasmussen CMØ, Bond DPG, Canfield DE. Shallow water euxinia during the Late Ordovician Mass Extinction – insights from coupled molybdenum and uranium isotope records. Earth-Science Reviews. 220, 103748. (2021) Link

A36. Farrell UC, … Dahl TW, …Sperling, EA. The Sedimentary Geochemistry and Paleoenvironments Project. Geobiology, 2021:00:1-12 Link

A35. Pan W, Cao M-C, Du Y-S, Cheng M, Zhou Y-Q, Algeo T, Zhao M-Y, Thibault N, Li C, Wei G-Y, Dahl TW. Paired U and Mo isotope evidence for widespread anoxia in the Cryogenian interglacial ocean. Precambrian Research, 361, 106244 (2021).

B3. Dahl TW and Arens SKM. Land plant evolution and global erosion rates: Reply to Neil S. Davies and William J. McMahon. Chemical Geology 573, 120167 (2021) Link

A34. Mehra A, Keller B, Zhang T, Tosca NJ, McLennan SM, …, Dahl TW, … Strauss JV Curation and analysis of global sedimentary geochemical data to inform Earth history, GSA Today, 31, 5, 1–9 (2021). Link


A33. Zhao H, Dahl TW, Chen Z-Q, Algeo TJ, Zhang L, Hu Z, Liu Y, Hu Z. Anomalous marine calcium cycle linked to carbonate factory change after the Smithian Thermal Maximum (Early Triassic). Earth-Science Reviews. 211, 103418 (2020).

A32. Lu X, Dahl TW, Zheng W, Wang S, Kendall B. Estimating ancient seawater isotope compositions and global ocean redox conditions by coupling the molybdenum and uranium isotope systems of euxinic organic-rich mudrocks. Geochimica et Cosmochimica Acta (2020) Link

A31. Sørensen AL, Nielsen AT, Thibault N, Zhao Z, Schovsbo NH, Dahl TW. Astronomically forced climate change in the late Cambrian. Earth and Planetary Science Letters (2020) Link Preprint

A30. Livermore B, Dahl TW, Bizzarro M, Connelly J. Uranium isotope compositions of biogenic carbonates – implications for U uptake in shells and the application of the paleo-ocean oxygenation proxy. Geochimica et Cosmochimica Acta (2020), Link

A29. Del Rey A, Havsteen JC, Bizzarro M, Dahl TW. Untangling the diagenetic history of uranium isotopes inmarine carbonates: A case study tracing thed238U compositionof late Silurian oceans using calcitic brachiopod shells. Geochimica et Cosmochimica Acta (2020), Link.

A28. Zhang F, del Rey A, Romaniello JS, Chen X, Planavsky NJ, Dahl TW, Lenton TM, Clarkson MO, Lau KV, Li Z, Zhao M, Algeo TJ, Anbar AD. Uranium isotopes in marine carbonates as a global ocean paleoredox proxy: A critical review. Geochimica et Cosmochimica Acta (2020), Link).

A27. Dahl TW, Arens SKM. The impacts of land plant evolution on Earth’s climate and oxygenation state – An interdisciplinary review. Chemical Geology, available online (2020). Open access

A26. Cao M, Zhang F, Daines SJ, Lenton TM, Zhou Y, Dahl TW, Algeo TJ, Shi W, Anbar A, Chen Y, Shen S-Z. Comparison of Ediacaran platform and slope δ238U records in South China: Confirmation of global deep-ocean oxygenation and implications for origin of the Shuram negative δ13Ccarb excursion. Geochimica et Cosmochimica Acta, available online (2020). Link

A25. Zhang F, Cui Y, Zhang H, Dahl TW, Krainer K, Shen S, Anbar AD. Two distinct episodes of marine anoxia during the Permian-Triassic crisis evidenced by uranium isotopes in marine dolomites. Geochimica et Cosmochimica Acta, available online (2020). Link

A24. Zhang F, Dahl TW, Lenton TM, Luo G, Shen S, Algeo TJ, Planavsky N, Liu J, Cui Y, Qie W, Romaniello SJ, Anbar AD. Extensive marine anoxia associated with the Late Devonian Hangenberg Crisis. Earth and Planetary Science Letters, available online (2020). Link


A23. Dahl TW, Connelly JN, Li D, Kouchinsky A, Gill BC, Porter S, Maloof AC, Bizzarro M. Atmosphere-ocean oxygen and productivity dynamics during early animal radiations. Proceedings of the National Academy of Sciences, 116 (39) 19352–19361 (2019). Open access   Press release

A22. Dahl TW, Siggard-Andersen M-L, Schovsbo N, Kjær K, Nielsen AT. Brief oxygenation events in Cambrian anoxic oceans solves the animal breathing paradox. Sci. Rep, 9, 1–9 (2019). Open access   Press release (in Danish)  Videnskab-dk


A21. Boyle RA, Dahl TW, Bjerrum CJ, Canfield DE. Bioturbation and directionality in Earth’s carbon isotope record across the Neoproterozoic–Cambrian transition. Geobiology, 2018, 1–27. pdf

A20. Scheller EL, Dickson A, Canfield DE, Korte C, Kristiansen KK, Dahl TW. Ocean redox conditions between the Snowballs – geochemical constraints from Arena Formation, East Greenland. Precambrian Research, 319, 173–186 (2018), pdf.


A19. Dahl TW, Connelly JN, Kouchinsky A, Gill BC, Månsson SF, Bizzarro M. Reorganization of Earth’s biogeochemical cycles briefly oxygenated the oceans 520 Myr ago. Geochemical Perspectives Letters 3, 210–220 (2017). Open access

A18. Dahl TW and Wirth S. Molybdenum isotope fractionation in a sulfidic lake – testing ways to discern isotope fractionation processes in euxinic sediments. Chemical Geology 460, 84–92. (2017). pdf

A17. Kendall, B†and Dahl, TW† and Anbar, A.D. (2017) The Stable Isotope Geochemistry of Molybdenum. Reviews in Mineralogy and Geochemistry 82, 683–732. pdf


A16. Dahl TW, Chappaz A, Hoek J, McKenzie C, Svane S, Canfield DE. Evidence of molybdenum interaction with particulate organic matter under sulfidic conditions. Early View pdf.

A15. Lenton T, Dahl TW, Daines S, Mills B, Ozaki K, Saltzman MR, Porada P. Earliest land plants created modern levels of atmospheric oxygen. Proc Natl Acad Sci 113, 9704–9 (2016) pdf  press (DK)

C1. Dahl TW. Identifying remnants of early Earth. Science, 352(6287): 768-769. pdf

B3. Zhang S, Wang X, Wang H, Bjerrum CJ, Hammarlund EU, Dahl TW and Canfield DE. Reply to Planavsky et al.: [strong evidence for high atmospheric oxygen levels 1400 million years ago. Proceedings of the National Academy of Sciences (Early edition online). pdf


A14. Boyle RA, Dahl TW, Dale A, Shields-Zhou GA, Zhu M, Brasier MD, Canfield DE, Lenton TM Stabilization of the coupled oxygen and phosphorus cycles by the evolution of bioturbation. 7, 671–676 (2014). Open access pdf teaser

A13. Dahl TW, Boyle RA, Canfield DE, Connelly JN, Gill BC, Lenton TM, Bizzarro M. Uranium isotopes distinguish two geochemically distinct stages during the later Cambrian SPICE event. Earth and Planetary Science Letters 401, 313-326 (2014). pdf teaser


A12. Overballe-Petersen, Harms, Orlando, Mayar, Rasmussen, Dahl TW, Rosing, Poole, Sicheritz-Ponten, Brunak, Wackernagel, Inselmann, de Vries, Pybus, Nielsen, Johnsen, Nielsen, Willerslev. Bacterial natural transformation by highly fragmented and damaged DNA (2013). pdf

A11. Wirth SB, Gilli A, Niemann H, Dahl TW, Ravasi D, Lehmann MF, Peduzzi R, Peduzzi S, Tonolla M, and Anselmetti FS, Combining sedimentological, trace metal (Mn, Mo) and molecular evidence for reconstructing past water-column redox conditions: The example of meromictic Lake Cadagno (Swiss Alps). Geochimica et Cosmochimica Acta 120: 220–238 (2013). pdf teaser

A10. Dahl TW, Ruhl M, Hammarlund E, Canfield DE, Rosing M, Bjerrum CJ. Tracing euxinia from elevated molybdenum concentrations in sediments using handheld x-ray fluorescence spectroscopy (HH-XRF). Chemical Geology. 360-361: 241–251 (2013). pdf teaser

A9. Balslev-Clausen D, Dahl TW, Saad N, Rosing, MT. Precise and accurate d13C analysis of rock samples using Flash Combustion-Cavity Ring Down Laser Spectroscopy. Journal of Analytical Atomic Spectrometry, 28(4): 516-523 (2013). front cover pdf teaser

A8. Dahl TW, Chappaz A, Fitts JP, Lyons TW, 2013. Molybdenum reduction in a sulfidic lake: Evidence from X-ray absorption fine-structure spectroscopy and implications for the Mo paleoproxy. Geochimica Et Cosmochimica Acta, 103: 213-231. pdf teaser


A7. Hammarlund EU, Dahl TW, Harper, DAT, Bond DPG, Bjerrum CJ, Bengtson S, Schovsbo NH, Schönlaub HP, Zalasiewicz JA, Canfield DE, A Sulfidic Driver for the end-Ordovician (Hirnantian) Deep-Water Extinction. Earth and Planetary Science Letters 331-332, 128-139 (2012). pdf teaser


A6. Dahl TW, Canfield DE., Rosing MT, Frei RE, Gordon GW., Knoll A, Anbar AD, Molybdenum abundance and isotopic evidence for expanded sulfidic water masses in ~750 Ma oceans. pdf supplement 

A5. Dahl TW and Hammarlund E, Do large predatory fish track ocean oxygenation? Communicative and Integrative Biology. 4:1, 1-3 Jan/Feb 2011. pdf


B1. Dahl TW, Hammarlund EH, Anbar AD, Bond DPG, Gill BC, Gordon GW, Knoll AH, Nielsen AT, Canfield DE. Reply to Butterfield: The Devonian radiation of large predatory fish coincided with elevated atmospheric oxygen levels PNAS 107, 17911-17915 (2010). pdf

A4. Dahl TW, Hammarlund EH, Anbar AD, Bond DPG, Gill BC, Gordon GW, Knoll AH, Nielsen AT, Schovsbo NH, Canfield DE. A Devonian rise of atmospheric oxygen correlated to the radiations of terrestrial plants and predatory fish. PNAS 107, 17911-17915 (2010). pdf supplement

A3. Dahl TW and Stevenson DJ. Turbulent Mixing of Metal and Silicate during Planet Accretion – and interpretation of the Hf-W chronometer. Earth and Planetary Science Letters 295 pp. 177-186 (2010) pdf supplement pdf supplement teaser

A2. Dahl TW, Clausen AU, Hansen PB, The human impact on natural rock reserves using basalt, anorthosite, and carbonates as raw materials in insulation products, International Geology Review 53, 894–904 (2011). pdf

A1. Dahl TW, Anbar A, Gordon G, Rosing M, Frei R, Canfield DE, 2010. The behavior of molybdenum and its isotopes across the chemocline and in the sediments of sulfidic Lake Cadagno, Switzerland. Geochimica Et Cosmochimica Acta 74., 144-163. pdf supplement

Theses and Study projects

2019 Sørensen AL, Orbitally forced climate change in the late Cambrian. MSc thesis

2019 Havsteen JC, Calibrating the δ238U paleoredox proxy, using calcitic brachiopods, across the late Silurian Lau event. MSc thesis

2017 Månsson S, Did Bioturbating Animals in the Early Cambrian Period Influence the Biogeochemical Cycles of Carbon and Sulfur? MSc thesis

2017 Harding MAR, Surface analyses of fossil leaves. BSc thesis

2016 Sørensen AL, Alunskifer Havets bundmiljø og liv BSc thesis (Danish)


2008 Dahl TW, PhD thesis about Molybdenum isotope fractionation.
2005  Dahl TW, Master’s thesis about core formation and the age of the Moon.
2003 Dahl TW, SURF thesis about aspects of turbulent mixing in planets.
2003 Dahl TW, Magnetisme på Mars, bachelor’s thesis (Danish)

Teaching material


2022 Dahl TW, Leer KL, Schäfer U. PlanetenKarten (in German). Scientific Playground
2022 Dahl TW, Leer KL, Rekaa V., Planet-Kort (in Norwegian). Scientific Playground

2022 Dahl TW, Leer KL Planetkort (4th edition). Scientific Playground.

2017 Dahl TW & Overballe-Petersen S. Mikrobekort for Videnskabsklubben, Scientific Playground

2017 Dahl TW, Leer KL, Planetkort. Scientific Playground (3rd edition)

2017 Dahl TW, Leer KL, PlanetCards (in English). Scientific Playground (2017) EAN-13: 5700002085221

2012 Dahl TW, Kock B., + scientific playground team PlanetCards for Apple iPhone/iPod.
2011 Dahl TW, Leer K., Pagh M. Planetkort 2nd ed. Forlaget Meloni. ISBN 978-87-92505-57-6
2008 Jensen F, Dahl, TW, Leer K, Pagh M. Planetkort lærervejledning. Geografforlaget
2007 Dahl TW, Leer K.L., Pagh M. Planetkort. Geografforlaget ISBN: 978-87-7702-522-8 



Press releases

P1. Researchers reject 30-year-old paradigm: The emergence of forests did not reduce the amount of CO2 in the atmosphere, 2022 (Nature Communications)

P2. New research into the greatest increase in marine biodiversity in the history of the Earth can help us understand and control ocean deoxygenation, 2022 (Nature Communications Earth & Environment)

P3. Månen gav de første dyr på Jorden en kortere dag, 2020 (EPSL)

P4. Humble moss helped create our oxygen-rich atmosphere, 2016 (PNAS)

P5. Burrowing animals – key to stabilizing Earth’s oxygen 2014 (Nature Geoscience).

P6. Poisonous oceans delayed animal evolution, 2011 (EPSL)

P7. Oxygenation by land plants kickstarted evolutionary drama, 2010 (PNAS)

P8. Earth and Moon formed later than previously thought, 2010 (EPSL)