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Professional biography

I am a palaeoceanographer and foraminiferal micropalaeontologist and have a particular interest in:

  • palaeoceanography & carbon cycling of past warm 'greenhouse' climate regimes
  • interactions between ocean circulation, ocean carbonate chemistry & atmospheric CO2
  • role of climatic change in structuring ocean ecosystems and evolution
  • geochemical utility of fossil foraminifera shells preserved in deep-sea sediments

Research interests

Much of my work has involved understanding the nature and causes of climatic change during the global warmth of the Eocene and mid-Cretaceous 'greenhouse' regimes. Another active research direction involves exploring the relationships between ocean circulation, ocean carbonate chemistry and atmospheric CO2 across a range of timescales. I am also investigating the role of climate change and switches in ocean circulation in structuring plankton biogeography, modulating inter-ocean exchanges of plankton populations and driving plankton extinctions.

Publications:

Boyle, P.R., Romans, B.W., Tucholke, B.E., Norris, R., Swift, S.A. & Sexton, P.F. (2017), Cenozoic North Atlantic deep circulation history recorded in contourite drifts, offshore Newfoundland, Canada, Marine Geology, 385, 185-203.

Hull, P.M., Bohaty, S.M., Cameron, A., Coxall, H.K., D’haenens, S., De Vleeschouwer, D., Elder, L.E., Friedrich, O., Kerr, K., Turner, S.K., Kordesch, W.E.C., Moriya, K., Norris, R.N., Opdyke, B.N., Penman, D.E., Pälike, H., Wilson, P.A., Sexton, P.F., Vahlenkamp, M., Wu, F., and Zachos, J.C., 2017. Data report: coarse fraction record for the Eocene megasplice at IODP Sites U1406, U1408, U1409, and U1411. In Norris, R.D., Wilson, P.A, Blum, P., and the Expedition 342 Scientists, Proceedings of the Integrated Ocean Drilling Program, 342: College Station, TX (Integrated Ocean Drilling Program). doi:10.2204/iodp.proc.342.203.2017

Penman, D.E., Kirtland-Turner, S., Sexton, P.F., Norris, R., Dickson, A., Boulila, S., Ridgwell, A., Zeebe, R., Zachos, J., Cameron, A., Westerhold, T. and Röhl, U. (2016), A carbonate compensation depth overshoot in the aftermath of the Palaeocene-Eocene Thermal Maximum, Nature Geoscience, 9, 575–580.

Salmon, K.H., Anand, P., Sexton, P.F. & Conte, M. (2016), Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies, Earth and Planetary Science Letters, 449, 372-381.

Möbius, I., Friedrich, O., Edgar, K.M. & Sexton, P.F. (2015), Episodes of intensified biological productivity in the subtropical Atlantic Ocean during the termination of the Middle Eocene Climatic Optimum, Paleoceanography, 30, 1041-1058.

Martinez-Botí, M.A., Foster, G.L., Chalk, T. B., Rohling, E.J., Sexton, P.F., Lunt, D.J., Pancost, R.D., Badger, M.P.S. & Schmidt, D.N. (2015), Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records, Nature, 518, 49–54.

Salmon, K.H., Anand, P., Sexton, P.F. & Conte, M. (2015), Upper ocean mixing controls the seasonality of planktonic foraminifer fluxes and associated strength of the carbonate pump in the oligotrophic North Atlantic, Biogeosciences, 12, 223-235.

Friedrich, O., Norris, R. D., Wilson, P. A., Opdyke, B. N., Badger, M., Bailey, I., Beddow-Twigg, H., Bohaty, S., Bolton, C., Bornemann, A., Crocker, A., Grützner, J., Herbert, T., Holbourn, A., Hull, P., Liebrand, D., Lippert, P., Lourens, L., Lyle, M., Pross, J., Rosenthal, Y., Sexton, P.F., Stärz, M., & Westerhold, T. (2015). Newfoundland Neogene sediment drifts - Transition from the Paleogene greenhouse to the modern icehouse, Scientific Drilling, 19, 39-42.

Foster, G.L. and Sexton, P.F. (2014), Enhanced carbon dioxide outgassing from the equatorial Atlantic during the last glacial, Geology, 42, 1003–1006.

Kirtland-Turner, S., Sexton, P.F., Charles, C. & Norris, R. (2014), Persistence of carbon release events through the peak of early Eocene global warmth, Nature Geoscience, 7, 748–751.

Kemp, D.B. and Sexton, P.F. (2014), Timescale uncertainty of abrupt events in the geologic record arising from unsteady sedimentation, Geology, 42, 891–894.

Expedition 342 Scientists (incl. Sexton, P.F.), 2014. Paleogene Newfoundland Sediment Drifts, Proc. IODP, 342: College Station, TX (Integrated Ocean Drilling Program). doi:10.2204/​iodp.proc.342.2014.

Hohbein, M., Sexton, P.F. and Cartwright, J. (2013), Onset of North Atlantic Deep Water production coincident with inception of the Cenozoic global cooling trend: Reply, Geology, 41, p. e292, doi:10.1130/G34655Y.1.

Edgar, K.M., Bohaty, S.M., Gibbs, S.J., Sexton, P.F., Norris, R.D. and Wilson, P.A. (2013), Symbiont ‘bleaching’ in planktic foraminifera during the Middle Eocene Climatic Optimum, Geology, 41, 15-18.

Sexton, P.F., Wilson, P.A., Bown, P.R. and Liebrand, D. (2013) Expedition 342: Paleogene Newfoundland Sediment Drifts, Integrated Ocean Drilling Program UK Newsletter, 38, 2-7.

Sexton, P.F. and Barker, S. (2012), Onset of 'Pacific-style' deep-sea sedimentary carbonate cycles at the mid-Pleistocene transition, Earth and Planetary Science Letters, 321, 81-94.

Hohbein, M., Sexton, P.F. and Cartwright, J. (2012), Onset of North Atlantic Deep Water production coincident with inception of the Cenozoic global cooling trend, Geology, 40, 255-258.

Expedition 342 Scientists (incl. Sexton, P.F.) (2012). Paleogene Newfoundland sediment drifts. IODP Prel. Rept., 342. doi:10.2204/iodp.pr.342.2012.

Sexton, P.F. and Norris, R.D. (2011), High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles, Earth and Planetary Science Letters, 311, 69-81.

Sexton, P.F., Norris, R.D., Wilson, P.A., Pälike, H., Westerhold, T., Röhl, U., Bolton, C. and Gibbs, S. (2011), Eocene global warming events driven by ventilation of oceanic dissolved organic carbon, Nature, 471, 349-352.

Edgar, K.M., Wilson, P.A., Sexton, P.F., Gibbs, S.J., Roberts, A.P. and Norris, R.D. (2010), New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes, Palaeogeography, Palaeoclimatology, Palaeoecology, 297, 670-682.

Sexton, P.F. and Wilson, P.A. (2009), Preservation of benthic foraminifera and reliability of deep-sea temperature records: The importance of sedimentation rates, lithology and the need to examine test wall structure, Paleoceanography, 24, PA2208, doi:10.1029/2008PA001650.

Sexton, P.F. and Norris, R.D. (2008), Dispersal and biogeography of marine plankton: Long-distance dispersal of the foraminifer Truncorotalia truncatulinoides, Geology, 36, 899-902.

Edgar, K.M., Wilson, P.A., Sexton, P.F. and Suganuma, Y. (2007), No extreme bipolar glaciation during the main Eocene calcite compensation shift, Nature, 448, 908-911.

Coxall, H.K., Wilson, P.A., Pearson, P.N. and Sexton, P.F. (2007), Iterative evolution of digitate planktonic foraminifera, Paleobiology, 33(4), 495-516.

Sexton, P.F., Wilson, P.A. and Pearson, P.N. (2006), Microstructural and geochemical perspectives on planktic foraminiferal preservation: 'Glassy' versus 'Frosty', Geochem. Geophys. Geosyst., 7, Q12P19, doi:10.1029/2006GC001291.

Sexton, P.F., Wilson, P.A. and Norris, R.D. (2006), Testing the Cenozoic multi-site composite d18O and d13C curves: New mono-specific Eocene records from a single locality, Demerara Rise (Ocean Drilling Program Leg 207), Paleoceanography, 21, PA2019, doi:10.1029/2005PA001253.

Sexton, P.F., Wilson, P.A. and Pearson, P.N. (2006), Palaeoecology of late middle Eocene planktic foraminifera and evolutionary implications, Marine Micropaleontology, 60, 1-16.

Danelian T, Le Callonnec L, Erbacher J et al. (incl. Sexton P.F.), (2005), Preliminary results on Cretaceous-Cenozoic tropical Atlantic pelagic sedimentation (Demerara Rise, ODP Leg 207), Comptes Rendus Geoscience, 337 (6), 609-616.

Erbacher, J., Mosher, D., Malone, M. and ODP Leg 207 Scientific Party (incl. Sexton, P.F.) (2004), Drilling probes past carbon cycle perturbations on Demerara Rise, Eos (Trans. AGU), 85, 57-63.

Sexton, P.F., Thurow, J. and Wilson, P.A. (2003), ODP Leg 207: Demerara Rise - Equatorial Cretaceous and Palaeogene palaeoceanographic transect, UK ODP Newsletter, 29, 18-21.

Sexton, P.F. and Norris, R.D. (2002), Orbital control of late Pliocene planktic foraminiferal biogeography, Newsletter of Micropalaeontology, 66, 18-19.

 

Professional Experience:

2016 -          Senior Lecturer, The Open University

2012 - 2016  Lecturer, The Open University

2010 - 2012  Leverhulme Trust Research Fellow, The Open University

2009 - 2010  EC Marie Curie Research Fellow, Cardiff University

2006 - 2009  EC Marie Curie Research Fellow, Scripps Institution of Oceanography, USA

2005 - 2006   Postdoctoral Research Scientist, National Oceanography Centre, Southampton

2001 - 2001   Visiting Scholar, Woods Hole Oceanographic Institution, USA

2000 - 2005   Postgraduate Research Student, National Oceanography Centre, Southampton

Teaching interests

At The Open University (the world-leader in distance teaching):

S330  Oceanography (30 credits) 2014-present, module team Chair. 2010-2014, module team member.

S366  Evolution (30 credits) 2010-2015, module team member, responsible for Macroevolution and Palaeontology (~ one third of module)

S175  Frozen Planet (10 credits) 2013-present, module team Chair

SXG288  Practical Science: Earth and Environment (30 credits) 2013-2014, module team Chair

S104  Exploring Science (60 credits) 2013-2014, module team member, responsible for Earth Science

S209  Earth Science (60 credits) 2014-present, module team member, responsible for Palaeontology, and Sedimentary Processes/Environments (~40% of module)                            

S309  Earth System Processes (60 credits) 2014-present, production module team member, responsible for the Oceans block (3 of 6)

Research Activity

Research groups

NameTypeParent Unit
Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)CentreFaculty of Science

Publications

Cenozoic North Atlantic deep circulation history recorded in contourite drifts, offshore Newfoundland, Canada (2017-03-01)
Boyle, Patrick R.; Romans, Brian W.; Tucholke, Brian E.; Norris, Richard D.; Swift, Stephen A. and Sexton, Philip F.
Marine Geology, 385 (pp. 185-203)
Calcification and growth processes in planktonic foraminifera complicate the use of B/Ca and U/Ca as carbonate chemistry proxies (2016-09-01)
Salmon, Kate H.; Anand, Pallavi; Sexton, Philip F. and Conte, Maureen
Earth and Planetary Science Letters, 449 (pp. 372-381)
An abyssal carbonate compensation depth overshoot in the aftermath of the Palaeocene–Eocene Thermal Maximum (2016-08)
Penman, Donald E.; Kirtland-Turner, Sandra; Sexton, Philip F.; Norris, Richard D.; Dickson, Alexander J.; Boulila, Slah; Ridgwell, Andy; Zeebe, Richard E.; Zachos, James C.; Cameron, Adele; Westerhold, Thomas and Röhl, Ursula
Nature Geoscience, 9 (pp. 575-580)
Episodes of intensified biological productivity in the subtropical Atlantic Ocean during the termination of the Middle Eocene Climatic Optimum (MECO) (2015-08-01)
Moebius, Iris; Friedrich, Oliver; Edgar, Kirsty M. and Sexton, Philip F.
Paleoceanography, 30(8) (pp. 1041-1058)
Newfoundland Neogene sediment drifts: transition from the Paleogene greenhouse to the modern icehouse (2015-05-29)
Friedrich, O.; Norris, R. D.; Wilson, P. A.; Opdyke, B. N.; workshop participants, ; Badger, Marcus and Sexton, Philip
Scientific Drilling, 19 (pp. 39-42)
Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records (2015-02-05)
Martinez-Botí, M. A.; Foster, G. L.; Chalk, T. B.; Rohling, E. J.; Sexton, P. F.; Lunt, D. J.; Pancost, R. D.; Badger, M. P. S. and Schmidt, D. N.
Nature, 518(7537) (pp. 49-54)
Upper ocean mixing controls the seasonality of planktonic foraminifer fluxes and associated strength of the carbonate pump in the oligotrophic North Atlantic (2015-01-13)
Salmon, K. H.; Anand, P.; Sexton, P. F. and Conte, M.
Biogeosciences, 12(1) (pp. 223-235)
Enhanced carbon dioxide outgassing from the eastern equatorial Atlantic during the last glacial (2014-11)
Foster, G. L. and Sexton, P. F.
Geology, 42(11) (pp. 1003-1006)
Persistence of carbon release events through the peak of early Eocene global warmth (2014-10)
Kirtland Turner, Sandra; Sexton, Philip; Charles, Christopher D. and Norris, Richard D.
Nature Geoscience, 7(10) (pp. 748-751)
Timescale uncertainty of abrupt events in the geologic record arising from unsteady sedimentation (2014-09)
Kemp, David B. and Sexton, Philip F.
Geology, 42(10) (pp. 891-894)
Onset of North Atlantic Deep Water production coincident with inception of the Cenozoic global cooling trend: Reply (2013-09)
Hohbein, Michael W.; Sexton, Philip F. and Cartwright, Joseph A.
Geology, 41(9) (e292)
Expedition 342: Paleogene Newfoundland Sediment Drifts (2013-08)
Integrated Ocean Drilling Program: UK Newsletter, 38 (pp. 2-7)
Symbiont ‘bleaching’ in planktic foraminifera during the Middle Eocene Climatic Optimum (2013-01)
Edgar, K. M.; Bohaty, S. M.; Gibbs, S. J.; Sexton, P. F.; Norris, R. D. and Wilson, P. A.
Geology, 41(1) (pp. 15-18)
Onset of ‘Pacific-style’ deep-sea sedimentary carbonate cycles at the mid-Pleistocene transition (2012-03)
Sexton, Philip F. and Barker, Stephen
Earth and Planetary Science Letters, 321-322 (pp. 81-94)
Onset of North Atlantic Deep Water production coincident with inception of the Cenozoic global cooling trend (2012)
Hohbein, Michael W.; Sexton, Philip F. and Cartwright, Joseph A.
Geology, 40(3) (pp. 255-258)
High latitude regulation of low latitude thermocline ventilation and planktic foraminifer populations across glacial-interglacial cycles (2011-11)
Sexton, Philip F. and Norris, Richard D.
Earth and Planetary Science Letters, 311(1-2) (pp. 69-81)
Eocene global warming events driven by ventilation of oceanic dissolved organic carbon (2011-03)
Sexton, Philip F.; Norris, Richard D.; Wilson, Paul A.; Pälike, Heiko; Westerhold, Thomas; Röhl, Ursula; Bolton, Clara T. and Gibbs, Samantha
Nature, 471 (pp. 349-352)
New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes (2010-11-20)
Edgar, K. M.; Wilson, P. A.; Sexton, P. F.; Gibbs, S. J.; Roberts, A. P. and Norris, R. D.
Palaeogeography, Palaeoclimatology, Palaeoecology, 297(3-4) (pp. 670-682)
Preservation of benthic foraminifera and reliability of deep-sea temperature records: Importance of sedimentation rates, lithology, and the need to examine test wall structure (2009-05)
Sexton, Philip F. and Wilson, Paul A.
Paleoceanography, 24 (PA2208)
Dispersal and biogeography of marine plankton: Long-distance dispersal of the foraminifer Truncorotalia truncatulinoides (2008-11)
Sexton, Philip F. and Norris, Richard D.
Geology, 36(11) (pp. 899-902)
Iterative evolution of digitate planktonic foraminifera (2007-10)
Coxall, Helen K.; Wilson, Paul A.; Pearson, Paul N. and Sexton, Philip F.
Paleobiology, 33(4) (pp. 495-516)
No extreme bipolar glaciation during the main Eocene calcite compensation shift (2007-08)
Edgar, Kirsty M.; Wilson, Paul A.; Sexton, Philip F. and Suganuma, Yusuke
Nature, 448 (pp. 908-911)
Microstructural and geochemical perspectives on planktic foraminiferal preservation: “Glassy” versus “Frosty” (2006-12)
Sexton, Philip F.; Wilson, Paul A. and Pearson, Paul N.
Geochemistry Geophysics Geosystems, 7(12) (Q12P19)
Palaeoecology of late middle Eocene planktic foraminifera and evolutionary implications (2006-06-27)
Sexton, Philip F.; Wilson, Paul A. and Pearson, Paul N.
Marine Micropaleontology, 60(1) (pp. 1-16)
Testing the Cenozoic multisite composite δ18O and δ13C curves: new monospecific Eocene records from a single locality, Demerara Rise (Ocean Drilling Program Leg 207) (2006-06)
Sexton, Philip F; Wilson, Paul A. and Norris, Richard D.
Paleoceanography, 21 (PA2019)
Preliminary results on Cretaceous-Tertiary tropical Atlantic pelagic sedimentation (Demerara Rise, ODP Leg 207) (2005-03)
Danelian, Taniel; Le Callonec, Laurence; Erbacher, Jochen; Mosher, David C.; Malone, Mitchell J.; Berti, Debora; Bice, Karen L.; Bostock, Helen; Brumsack, Hans-Jurgen; Forster, Astrid; Heidersdorf, Felix; Henderiks, Jorijntje; Janecek, Thomas J.; Junium, Christopher; Macleod, Ken; Meyers, Philip A.; Mutterlose, Jorg H.; Nishi, Hiroshi; Norris, Richard D.; Ogg, James G.; O’Regan, Matthew A.; Rea, Brice; Sexton, Philip; Sturt-Fredricks, Helen; Suganuma, Yusuke; Thurow, Jurgen W.; Wilson, Paul A.; Wise, Sherwood W. and Glatz, Catherine
Comptes Rendus Geoscience, 337(6) (pp. 609-616)
Paleogene Newfoundland sediment drifts (2012-10-01)
Norris, Richard D.; Wilson, Paul A.; Blum, Peter; Fehr, Annick; Agnini, Claudia; Bornemann, André; Boulila, Slah; Brown, Paul R.; Cournede, Cecile; Friedrich, Oliver; Ghosh, Amit Kumar; Hollis, Christopher J.; Hull, Pincelli M.; Jo, Kyoungnam; Junium, Christopher K.; Kaneko, Masanori; Liebrand, Diederik; Lippert, Peter C.; Liu, Zhonghui; Matsui, Hiroki; Moriya, Kazuyoshi; Nishi, Hiroshi; Opdyke, Bradley N.; Penman, Donald; Romans, Brian; Scher, Howie D.; Sexton, Philip; Takagi, Haruka; Turner, Sandra Kirtland; Whiteside, Jessica H.; Yamaguchi, Tatsuhiko and Yamamoto, Yuhji
Integrated Ocean Drilling Program Expedition 342
Publisher : Integrated Ocean Drilling Program Management International, Inc. | Published : La Jolla, CA
Low sensitivity of Alkenone carbon isotopes to atmospheric CO2 during the Plio-Pleistocene (2015-08-16)
Pancost, Richard D.; Badger, Marcus P. S.; Chalk, Thomas B.; Foster, Gavin L.; Bown, Paul R.; Gibbs, Samantha J.; Sexton, Philip F.; Pälike, Heiko and Mackensen, Andreas
In : Goldschmidt Conference 2015 (16-21 August 2015, Prague, Czech Republic)
Biomarker approaches to greenhouse gas estimations through the Cenozoic: Recent developments and future directions (2015)
Badger, Marcus Peter Sebastian; Chalk, Thomas Ben; Foster, Gavin L.; Bown, Paul R.; Gibbs, Samantha; Sexton, Philip F.; Schmidt, Daniela N.; Pälike, Heiko; Mackensen, Andreas and Pancost, Richard D.
In : AGU Fall Meeting (14-18 December 2015, San Francisco, California)
Ocean redox across the PETM: stable Cr isotopes in planktic foraminifera (2013)
Dixon, Sophie; Parkinson, Ian; Sexton, Philip; Fehr, Manuela; Peacock, Caroline and James, Rachael
In : Geochemistry Group RiP meeting 2013 (14 March 2013, Milton Keynes)
Tracking changes in ocean redox during the PETM using stable chromium isotopes (2012)
Dixon, Sophie K.; Parkinson, Ian J.; Sexton, Philip; Fehr, Manuela; James, Rachael Helen and Peacock, Caroline
In : AGU Fall Meeting (3-7 December 2012, San Francisco, CA, USA)