My research is focused on:
1) the interactions between climate-induced change in seawater chemistry and palaeoecological networks and the resultant consequences for carbonate deposition systems
2) the development or refinement of proxies to reconstruct past environments.
I am focusing on the Triassic, which is a wonderful time to explore such interactions. This period begins with the most profound mass-extinction on Earth and ends with another of the ‘big five’. In between these two mass-extinctions, there are times of slow recovery, crises, origination and the flourishing of marine biota. Major constituents of today’s marine ecosystems such as scleractinian corals, photosymbiosis in corals and calcareous nannoplankton appear during the Triassic. The impacts of these important newcomers on the marine ecosystem and on the carbonate depositional system have only been poorly understood to date.
Methodologically, my first priority is detailed studies of structures and depositional architectures of sedimentary successions, and the establishment of robust regional and stratigraphical frameworks. To reach these goals, extensive field data are essential. Since 2000, I have developed field expertise on the tethyan Triassic in Central Europe (Austria, Slovenia, Croatia, Hungary, Slovakia), in Turkey, Oman, Iran and the Indian Himalaya.
Once the regional and stratigraphical framework is well established, geochemical analyses and palaeobiological studies can be carried out. I think that an important effort has still to be produced to understand the behaviour of new palaeoenvironmental proxies (e.g. non-conventional isotopes, trace elements, biomarkers) during the early diagenesis of the sediments and their applicability in different palaeoecological settings. The Triassic with its extreme environments is of particular interest for this purpose, but this should be tested all other the Phanerozoic.
Two projects are going on:
1) Triassic microbialite reefs and post-extinction oolites
Microbialites were widespread during Precambrian time and became again abundant during the Early Triassic. A continuing problem is the precise determination of the conditions of growth, the processes leading to a non-obligatory calcification and the phylogenetic affiliations of the microorganisms involved in microbialite formation. In the same way, end-Silurian, end-Permian and end-Triassic extinction events are characterized by the deposition of ubiquitous oolites. The sedimentological, palaeoecological, isotopic and biogeochemical comparisons of the different types of microbial structures and of the oolites in different palaeoenvironmental settings will allow us to better understand the conditions of growth of the post-extinction microbialites and oolites and to assess water chemistry changes on shallow shelves in the aftermath of these major mass extinctions.
2) Emergence of pelagic calcification and its influence on seawater chemistry
Around the Norian-Rhaetian boundary (Late Triassic) the first coccolithophorids appeared alongside an explosion of calcareous nannolith productivity, and a noticeable bloom in reef abundance and diversity. This is in surprising contrast to a major extinction in conodonts, ammonoids and the bivalve Monotis observed at around the same time. I aim to establish the detailed timing of these events. One particular point of interest is the emergence of the calcifying plankton in the marine ecosystem shifting the major carbonate production from the shallow seas to the open marine realm. This is a paradigm change. To better understand the influence of the emergence of planktonic calcification on sea-water chemistry, I want to combines palaeontological studies of the calcareous nannoplankton, geochemistry on traditional (Ccarb, Corg) and non-traditional isotope system (Ca, Mg, Sr) and climate models.
Displaying of publications. Sorted by year, then title.
Mid-Norian to Hettangian record and time-specific oolites during the end-Triassic Mass Extinction at Wadi Milaha, Musandam Peninsula, United Arab EmiratesIngrid Urban, Isaline Demangel, Leopold Krystyn, Mikael Calner, Zsófia Kovács, et al.
(2023) Journal of Asian Earth Sciences: X, 9
Fate of calcareous nannofossils during the Rhaetian (Late Triassic) : evidence from the Northern Calcareous Alps, AustriaIsaline Demangel, Zsófia Kovács, Silvia Gardin, Leopold Krystyn, Werner E. Piller, et al.
(2023) Lethaia, 56
The Calcium Isotope (δ44/40Ca) Record Through Environmental Changes : Insights From the Late TriassicZsófia Kovács, Isaline Demangel, Andre Baldermann, Dorothee Hippler, Anne Désirée Schmitt, et al.
(2022) Geochemistry, Geophysics, Geosystems, 23
Identification and Current Palaeobiological Understanding of “Keratosa”-Type Nonspicular Demosponge Fossils in Carbonates : With a New Example from the Lowermost Triassic, ArmeniaCui Luo, Yu Pei, Sylvain Richoz, Qijian Li, Joachim Reitner
(2022) Life, 12
Volcanic temperature changes modulated volatile release and climate fluctuations at the end-Triassic mass extinctionKunio Kaiho, Daisuke Tanaka, Sylvain Richoz, David S. Jones, Ryosuke Saito, et al.
(2022) Earth and Planetary Science Letters, 579
Editorial preface to special issue : Triassic at the dawn of modern world in honour of Prof. Leopold KrystynY. D. Sun, S. Richoz, W. M. Kürschner
(2022) Global and Planetary Change, 208
Journal article (comment)
The Sedimentary Geochemistry and Paleoenvironments ProjectÚna C. Farrell, Emma Hammarlund, Sylvain Richoz, Erik A. Sperling
(2021) Geobiology, 19 p.545-556
Palaeo-environmental evolution of Central Asia during the Cenozoic : New insights from the continental sedimentary archive of the Valley of Lakes (Mongolia)Andre Baldermann, Oliver Wasser, Elshan Abdullayev, Stefano Bernasconi, Stefan Löhr, et al.
(2021) Climate of the Past, 17 p.1955-1972
Early Cambrian brachiopod-dominated shell concentrations from North-East Greenland : Environmental and taphonomic implicationsDavid A.T. Harper, Svend Stouge, Jørgen L. Christiansen, Timothy P. Topper, Carl Alwmark, et al.
(2021) Global and Planetary Change, 204
Sponge Takeover from End-Permian Mass Extinction to Early Induan Time : Records in Central Iran Microbial BuildupsAymon Baud, Sylvain Richoz, Rainer Brandner, Leopold Krystyn, Katrin Heindel, et al.
(2021) Frontiers in Earth Science, 9
Integrated bio-chemostratigraphy of Lower and Middle Triassic marine successions at Spiti in the Indian Himalaya : Implications for the Early Triassic nutrient crisisY. D. Sun, S. Richoz, L. Krystyn, S. E. Grasby, Y. L. Chen, et al.
(2021) Global and Planetary Change, 196
Smithian and Spathian (Early Triassic) conodonts from Oman and Croatia and their depth habitat revealedYanlong Chen, Michael M. Joachimski, Sylvain Richoz, Leopold Krystyn, Dunja Aljinović, et al.
(2021) Global and Planetary Change, 196
Development of early calcareous nannoplankton in the late Triassic (Northern Calcareous Alps, Austria)Isaline Demangel, Zsófia Kovács, Sylvain Richoz, Silvia Gardin, Leopold Krystyn, et al.
(2020) Global and Planetary Change, 193
Suppressed competitive exclusion enabled the proliferation of Permian/Triassic boundary microbialitesWilliam J. Foster, Katrin Heindel, Sylvain Richoz, Jana Gliwa, Daniel J. Lehrmann, et al.
(2020) Depositional Record, 6 p.62-74
New constraints on the evolution of 87Sr/86Sr of seawater during the Upper TriassicZsófia Kovács, Isaline Demangel, Sylvain Richoz, Dorothee Hippler, Andre Baldermann, et al.
(2020) Global and Planetary Change, 192
“Short” or “long” Rhaetian ? Astronomical calibration of Austrian key sectionsBruno Galbrun, Slah Boulila, Leopold Krystyn, Sylvain Richoz, Silvia Gardin, et al.
(2020) Global and Planetary Change, 192
The Smithian-Spathian boundary : A critical juncture in the Early Triassic recovery of marine ecosystemsThomas J. Algeo, Arnaud Brayard, Sylvain Richoz
(2019) Earth-Science Reviews, 195 p.1-6
Journal article (comment)
Orbital cyclicity in sedimentary sequence and climatic indications of C-O isotopes from Lower Cretaceous in Qingxi Sag, Jiuquan Basin, NW ChinaSiding Jin, Haiyang Cao, Hua Wang, Michael Wagreich, Sylvain Richoz
(2019) Geoscience Frontiers, 10 p.467-479
Anachronistic facies and carbon isotopes during the end-Permian biocrisis : Evidence from the mid-Tethys (Kisejin, Iran)Mahdi Maaleki-Moghadam, Behrouz Rafiei, Sylvain Richoz, Adam D. Woods, Leopold Krystyn
(2019) Palaeogeography, Palaeoclimatology, Palaeoecology, 516 p.364-383
Quantitative stratigraphic correlation of Tethyan conodonts across the Smithian-Spathian (Early Triassic) extinction eventYanlong Chen, Sylvain Richoz, Leopold Krystyn, Zhifei Zhang
(2019) Earth-Science Reviews, 195 p.37-51
Journal article review
The Origin of Carbonate Veins Within the Sedimentary Cover and Igneous Rocks of the Cocos Ridge : Results From IODP Hole U1414AJennifer Brandstätter, Walter Kurz, Sylvain Richoz, Matthew J. Cooper, Damon A.H. Teagle
(2018) Geochemistry, Geophysics, Geosystems, 19 p.3721-3738
The formation of microbial-metazoan bioherms and biostromes following the latest Permian mass extinctionKatrin Heindel, William J. Foster, Sylvain Richoz, Daniel Birgel, Vanessa Julie Roden, et al.
(2018) Gondwana Research, 61 p.187-202
Perturbations in the carbon cycle during the carnian humid episode : Carbonate carbon isotope records from southwestern China and Northern OmanY. D. Sun, S. Richoz, L. Krystyn, Z. T. Zhang, M. M. Joachimski
(2018) Journal of the Geological Society, 176 p.167-177
Western Tethyan Epeiric Ramp Setting in the Early Triassic : An Example from the Central Dinarides (Croatia)Dunja Aljinović, Micha Horacek, Leopold Krystyn, Sylvain Richoz, Tea Kolar-Jurkovšek, et al.
(2018) Journal of Earth Science, 29 p.806-823
Multiple sulfur-isotopic evidence for a shallowly stratified ocean following the Triassic-Jurassic boundary mass extinctionGenming Luo, Sylvain Richoz, Bas Van De Schootbrugge, Thomas J. Algeo, Shucheng Xie, et al.
(2018) Geochimica et Cosmochimica Acta, 231 p.73-87
Evidence for archaeal methanogenesis within veins at the onshore serpentinite-hosted Chimaera seeps, TurkeyJ. Zwicker, D. Birgel, W. Bach, S. Richoz, D. Smrzka, et al.
(2018) Chemical Geology , p.567-580
Multiple episodes of extensive marine anoxia linked to global warming and continental weathering following the latest Permian mass extinctionFeifei Zhang, Stephen J. Romaniello, Thomas J. Algeo, Kimberly V. Lau, Matthew E. Clapham, et al.
(2018) Science Advances, 4
Middle Triassic conodont assemblages from the Germanic Basin: implications for multi-element taxonomy and biogeographyYanlong Chen, Frank Scholze, Sylvain Richoz, Zhifei Zhang
(2018) Journal of Systematic Palaeontology , p.1-19
Global perturbation of the marine calcium cycle during the Permian-Triassic transitionJuan Carlos Silva-Tamayo, Kimberly V. Lau, Adam B. Jost, Jonathan L. Payne, Paul B. Wignall, et al.
(2018) Geological Society of America Bulletin, 130 p.1323-1338
Sponge-microbial build-ups from the lowermost Triassic Chanakhchi section in southern Armenia: Microfacies and stable carbon isotopesEvelyn Friesenbichler, Sylvain Richoz, Aymon Baud, Leopold Krystyn, Lilit Sahakyan, et al.
(2018) Palaeogeography, Palaeoclimatology, Palaeoecology, 490 p.653-672
Conodont biostratigraphy of the Early Triassic in eastern SloveniaT. Kolar-Jurkovšek, Y. L. Chen, B. Jurkovšek, M. Poljak, D. Aljinović, et al.
(2017) Paleontological Journal, 51 p.687-703
Geochemistry and mineralogy of the Oligo-Miocene sediments of the Valley of Lakes, MongoliaSylvain Richoz, Andre Baldermann, Andreas Frauwallner, Mathias Harzhauser, Gudrun Daxner-Höck, et al.
(2017) Palaeobiodiversity and Palaeoenvironments, 97 p.233-258
Revised middle Triassic stratigraphy of the Swiss Prealps based on conodonts and correlation to the Briançonnais (Western Alps)Aymon Baud, Pablo Plasencia, Francis Hirsch, Sylvain Richoz
(2016) Swiss Journal of Geosciences, 109 p.365-377
Stepwise onset of the Icehouse world and its impact on Oligo-Miocene Central Asian mammalsMathias Harzhauser, Gudrun Daxner-Höck, Paloma López-Guerrero, Olivier Maridet, Adriana Oliver, et al.
(2016) Scientific Reports, 6 p.1-8
Allometry in Anisian (Middle Triassic) segminiplanate conodonts and its implications for conodont taxonomyYanlong Chen, Thomas A. Neubauer, Leopold Krystyn, Sylvain Richoz
(2016) Palaeontology, 59 p.725-741
Reply to comments on : A review of the evolution, biostratigraphy, provincialism and diversity of Middle and early Late Triassic conodontsYanlong Chen, Leopold Krystyn, Michael J. Orchard, Xulong Lai, Sylvain Richoz
(2016) Papers in Palaeontology, 2 p.457-461
Journal article (comment)
Dynamic anoxic ferruginous conditions during the end-Permian mass extinction and recoveryM. O. Clarkson, R. A. Wood, S. W. Poulton, S. Richoz, R. J. Newton, et al.
(2016) Nature Communications, 7
A review of the evolution, biostratigraphy, provincialism and diversity of Middle and early Late Triassic conodontsYanlong Chen, Leopold Krystyn, Michael J. Orchard, Xu Long Lai, Sylvain Richoz
(2016) Papers in Palaeontology, 2 p.235-263
Journal article review
Distribution of iridium and associated geochemistry across the Triassic-Jurassic boundary in sections at Kuhjoch and Kendlbach, Northern Calcareous Alps, AustriaLawrence H. Tanner, Frank T. Kyte, Sylvain Richoz, Leopold Krystyn
(2016) Palaeogeography, Palaeoclimatology, Palaeoecology, 449 p.13-26
Early Triassic conodonts and carbonate carbon isotope record of the Idrija-Žiri area, SloveniaYanlong Chen, Tea Kolar-Jurkovšek, Bogdan Jurkovšek, Dunja Aljinović, Sylvain Richoz
(2016) Palaeogeography, Palaeoclimatology, Palaeoecology, 444 p.84-100
New data on the structure and age of the terminal Permian strata in the South Verkhoyansk region (northeastern Asia)A. S. Biakov, Yu D. Zakharov, M. Horacek, S. Richoz, R. V. Kutygin, et al.
(2016) Russian Geology and Geophysics, 57 p.282-293
Environmental controls on marine ecosystem recovery following mass extinctions, with an example from the Early TriassicHengye Wei, Jun Shen, Shane D. Schoepfer, Leo Krystyn, Sylvain Richoz, et al.
(2015) Earth-Science Reviews, 149 p.108-135
Journal article review
Early Triassic conodonts of Jiarong, Nanpanjiang Basin, southern Guizhou Province, South ChinaYanlong Chen, Haishui Jiang, Xulong Lai, Chunbo Yan, Sylvain Richoz, et al.
(2015) Journal of Asian Earth Sciences, 105 p.104-121
Ocean acidification and the Permo-Triassic mass extinctionM. O. Clarkson, S. A. Kasemann, R. A. Wood, T. M. Lenton, S. J. Daines, et al.
(2015) Science, 348 p.229-232
New hybodontiform and neoselachian sharks from the Lower Triassic of OmanMartha B. Koot, Gilles Cuny, Michael J. Orchard, Sylvain Richoz, Malcolm B. Hart, et al.
(2015) Journal of Systematic Palaeontology, 13 p.891-917
Importance of carbon isotopic data of the Permian-Triassic boundary layers in the Verkhoyansk region for the global correlation of the basal Triassic layerYu D. Zakharov, A. S. Biakov, S. Richoz, M. Horacek
(2015) Doklady Earth Sciences, 460 p.1-5
Biogeochemical formation of calyx-shaped carbonate crystal fans in the subsurface of the Early Triassic seafloorKatrin Heindel, Sylvain Richoz, Daniel Birgel, Rainer Brandner, Andreas Klügel, et al.
(2015) Gondwana Research, 27 p.840-861
Vertical δ13Corg gradients record changes in planktonic microbial community composition during the end-Permian mass extinctionGenming Luo, Thomas J. Algeo, Junhua Huang, Wenfeng Zhou, Yongbiao Wang, et al.
(2014) Palaeogeography, Palaeoclimatology, Palaeoecology, 396 p.119-131
Khuff margin: : Slope to oceanic deposits (Permian-Triassic Allochthons and Exotics, Oman)Sylvain Richoz
(2014) Permo-Triassic Sequence of the Arabian Plate , p.55-76
Size variation of conodonts during the Smithian-Spathian (early triassic) global warming eventYanlong Chen, Richard J. Twitchett, Haishui Jiang, Sylvain Richoz, Xulong Lai, et al.
(2013) Geology, 41 p.823-826
Microbes, mud and methane : Cause and consequence of recurrent early Jurassic anoxia following the end-Triassic mass extinctionBas Van de Schootbrugge, Aviv Bachan, Guillaume Suan, Sylvain Richoz, Jonathan L. Payne
(2013) Palaeontology, 56 p.685-709
A new high-resolution δ13C record for the Early Triassic : Insights from the Arabian PlatformM. O. Clarkson, S. Richoz, R. A. Wood, Florian Maurer, L. Krystyn, et al.
(2013) Gondwana Research, 24 p.233-242
The global stratotype sections and point (GSSP) for the base of the jurassic system at kuhjoch (Karwendel Mountains, Northern Calcareous Alps, Tyrol, Austria)A. V. Hillebrandt, L. Krystyn, W. M. Kürschner, N. R. Bonis, M. Ruhl, et al.
(2013) Episodes, 36 p.162-198
Where and when the earliest coccolithophores?Silvia Gardin, Leopold Krystyn, Sylvain Richoz, Annachiara Bartolini, Bruno Galbrun
(2012) Lethaia, 45 p.507-523
Hydrogen sulphide poisoning of shallow seas following the end-Triassic extinctionSylvain Richoz, Bas Van De Schootbrugge, Jörg Pross, Wilhelm Püttmann, Tracy M. Quan, et al.
(2012) Nature Geoscience, 5 p.662-667
The dispersal of Halimeda in northern hemisphere mid-latitudes : Palaeobiogeographical insightsMarkus Reuter, Werner E. Piller, Sylvain Richoz
(2012) Perspectives in Plant Ecology, Evolution and Systematics, 14 p.303-309
No causal link between terrestrial ecosystem change and methane release during the end-Triassic mass extinctionSofie Lindström, Bas van de Schootbrugge, Karen Dybkjær, Gunver Krarup Pedersen, Jens Fiebig, et al.
(2012) Geology, 40 p.531-534
The Buday'ah Formation, Sultanate of Oman : A Middle Permian to Early Triassic oceanic record of the Neotethys and the late Induan microsphere bloomAymon Baud, Sylvain Richoz, Benoit Beauchamp, Fabrice Cordey, Stephen Grasby, et al.
(2012) Journal of Asian Earth Sciences, 43 p.130-144