Sylvain Richoz
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.
Publications
Retrieved from Lund University's publications database
Publications
- 2019
- Anachronistic facies and carbon isotopes during the end-Permian biocrisis : Evidence from the mid-Tethys (Kisejin, Iran)
(2019) Palaeogeography, Palaeoclimatology, Palaeoecology
Journal article - Orbital cyclicity in sedimentary sequence and climatic indications of C-O isotopes from Lower Cretaceous in Qingxi Sag, Jiuquan Basin, NW China
(2019) Geoscience Frontiers
Journal article - Quantitative stratigraphic correlation of Tethyan conodonts across the Smithian-Spathian (Early Triassic) extinction event
(2019) Earth-Science Reviews
Journal article review - The Smithian-Spathian boundary : A critical juncture in the Early Triassic recovery of marine ecosystems
(2019) Earth-Science Reviews
Journal article (comment)
- Anachronistic facies and carbon isotopes during the end-Permian biocrisis : Evidence from the mid-Tethys (Kisejin, Iran)
- 2018
- Evidence for archaeal methanogenesis within veins at the onshore serpentinite-hosted Chimaera seeps, Turkey
(2018) Chemical Geology
Journal article - Global perturbation of the marine calcium cycle during the Permian-Triassic transition
(2018) Bulletin of the Geological Society of America
Journal article - Middle Triassic conodont assemblages from the Germanic Basin: implications for multi-element taxonomy and biogeography
(2018) Journal of Systematic Palaeontology
Journal article - Multiple episodes of extensive marine anoxia linked to global warming and continental weathering following the latest Permian mass extinction
(2018) Science Advances
Journal article - Multiple sulfur-isotopic evidence for a shallowly stratified ocean following the Triassic-Jurassic boundary mass extinction
(2018) Geochimica et Cosmochimica Acta
Journal article - Perturbations in the carbon cycle during the carnian humid episode : Carbonate carbon isotope records from southwestern China and Northern Oman
(2018) Journal of the Geological Society
Journal article - Sponge-microbial build-ups from the lowermost Triassic Chanakhchi section in southern Armenia: Microfacies and stable carbon isotopes
(2018) Palaeogeography, Palaeoclimatology, Palaeoecology
Journal article - The Origin of Carbonate Veins Within the Sedimentary Cover and Igneous Rocks of the Cocos Ridge : Results From IODP Hole U1414A
(2018) Geochemistry, Geophysics, Geosystems
Journal article - The formation of microbial-metazoan bioherms and biostromes following the latest Permian mass extinction
(2018) Gondwana Research
Journal article - Western Tethyan Epeiric Ramp Setting in the Early Triassic : An Example from the Central Dinarides (Croatia)
(2018) Journal of Earth Science
Journal article
- Evidence for archaeal methanogenesis within veins at the onshore serpentinite-hosted Chimaera seeps, Turkey
- 2017
- Conodont biostratigraphy of the Early Triassic in eastern Slovenia
(2017) Paleontological Journal
Journal article - Geochemistry and mineralogy of the Oligo-Miocene sediments of the Valley of Lakes, Mongolia
(2017) Palaeobiodiversity and Palaeoenvironments
Journal article
- Conodont biostratigraphy of the Early Triassic in eastern Slovenia
- 2016
- A review of the evolution, biostratigraphy, provincialism and diversity of Middle and early Late Triassic conodonts
(2016) Papers in Palaeontology
Journal article review - Allometry in Anisian (Middle Triassic) segminiplanate conodonts and its implications for conodont taxonomy
(2016) Palaeontology
Journal article - Distribution of iridium and associated geochemistry across the Triassic-Jurassic boundary in sections at Kuhjoch and Kendlbach, Northern Calcareous Alps, Austria
(2016) Palaeogeography, Palaeoclimatology, Palaeoecology
Journal article - Dynamic anoxic ferruginous conditions during the end-Permian mass extinction and recovery
(2016) Nature Communications
Journal article - Early Triassic conodonts and carbonate carbon isotope record of the Idrija-Žiri area, Slovenia
(2016) Palaeogeography, Palaeoclimatology, Palaeoecology
Journal article - New data on the structure and age of the terminal Permian strata in the South Verkhoyansk region (northeastern Asia)
(2016) Russian Geology and Geophysics
Journal article - Reply to comments on : A review of the evolution, biostratigraphy, provincialism and diversity of Middle and early Late Triassic conodonts
(2016) Papers in Palaeontology
Journal article (comment) - Revised middle Triassic stratigraphy of the Swiss Prealps based on conodonts and correlation to the Briançonnais (Western Alps)
(2016) Swiss Journal of Geosciences
Journal article - Stepwise onset of the Icehouse world and its impact on Oligo-Miocene Central Asian mammals
(2016) Scientific Reports
Journal article
- A review of the evolution, biostratigraphy, provincialism and diversity of Middle and early Late Triassic conodonts
- 2015
- Biogeochemical formation of calyx-shaped carbonate crystal fans in the subsurface of the Early Triassic seafloor
(2015) Gondwana Research
Journal article - Early Triassic conodonts of Jiarong, Nanpanjiang Basin, southern Guizhou Province, South China
(2015) Journal of Asian Earth Sciences
Journal article - Environmental controls on marine ecosystem recovery following mass extinctions, with an example from the Early Triassic
(2015) Earth-Science Reviews
Journal article review - Importance of carbon isotopic data of the Permian-Triassic boundary layers in the Verkhoyansk region for the global correlation of the basal Triassic layer
(2015) Doklady Earth Sciences
Journal article - New hybodontiform and neoselachian sharks from the Lower Triassic of Oman
(2015) Journal of Systematic Palaeontology
Journal article - Ocean acidification and the Permo-Triassic mass extinction
(2015) Science
Journal article
- Biogeochemical formation of calyx-shaped carbonate crystal fans in the subsurface of the Early Triassic seafloor
- 2014
- Khuff margin: : Slope to oceanic deposits (Permian-Triassic Allochthons and Exotics, Oman)
(2014)
Book chapter - Vertical δ13Corg gradients record changes in planktonic microbial community composition during the end-Permian mass extinction
(2014) Palaeogeography, Palaeoclimatology, Palaeoecology
Journal article
- Khuff margin: : Slope to oceanic deposits (Permian-Triassic Allochthons and Exotics, Oman)
- 2013
- A new high-resolution δ13C record for the Early Triassic : Insights from the Arabian Platform
(2013) Gondwana Research
Journal article - Microbes, mud and methane : Cause and consequence of recurrent early Jurassic anoxia following the end-Triassic mass extinction
(2013) Palaeontology
Journal article - Size variation of conodonts during the Smithian-Spathian (early triassic) global warming event
(2013) Geology
Journal article - The global stratotype sections and point (GSSP) for the base of the jurassic system at kuhjoch (Karwendel Mountains, Northern Calcareous Alps, Tyrol, Austria)
(2013) Episodes
Journal article
- A new high-resolution δ13C record for the Early Triassic : Insights from the Arabian Platform
- 2012
- Hydrogen sulphide poisoning of shallow seas following the end-Triassic extinction
(2012) Nature Geoscience
Journal article - No causal link between terrestrial ecosystem change and methane release during the end-Triassic mass extinction
(2012) Geology
Journal article - The Buday'ah Formation, Sultanate of Oman : A Middle Permian to Early Triassic oceanic record of the Neotethys and the late Induan microsphere bloom
(2012) Journal of Asian Earth Sciences
Journal article - The dispersal of Halimeda in northern hemisphere mid-latitudes : Palaeobiogeographical insights
(2012) Perspectives in Plant Ecology, Evolution and Systematics
Journal article - Where and when the earliest coccolithophores?
(2012) Lethaia
Journal article
- Hydrogen sulphide poisoning of shallow seas following the end-Triassic extinction
