An example of some ongoing research projects:
Archean – Paleoproterozoic
Investigating mechanisms of BIF generation and the associated drawdown of bio-essential metals and phosphate, to understand patterns of nutrient availability during early microbial evolution.
Constraining phosphorous cycling in ferruginous basins and potential controls on the environmental distribution of early eukaryotes.
Neoproterozoic – Palaeozoic
Tracking changes in oxygen availability on marine shelves to constrain the amount of habitable space during the rise of animal life.
Quantifying global fluxes in biogeochemical cycles in the modern ocean and terrestrial lakes and rivers.
We collect outcrop and core material, alongside detailed logs and geobiological data, and characterise it using petrography, as well as analytical techniques such as XRD and FTIR.
We apply a range of geochemical proxies to sediment samples, including isotopes (carbon, oxygen, sulfur, uranium, calcium and others) and trace metals (Fe speciation, REEs).
We recreate chemical sediments in the lab, synthesising minerals and quantifying their nucleation rates, solubility, and sorption properties using an anoxic glove box, solution analysis (spectrophotometry, ICP-MS and ICP-OES) and synchrotron techniques (XAS and nano-IR) .
We test geobiological hypotheses directly, by culturing algae in synthetic seawater and monitoring growth rates and metabolic health using a coulter counter, a plate reader, SEM and cell digests.
Tostevin, R., Bradbury, H. J., Shields, G. A., Wood, R. A., Bowyer, F., Penny, A., Turchyn, A. V., 2019. Calcium isotopes as a record of the marine calcium cycle versus carbonate diagenesis during the late Ediacaran. Chemical Geology. Download / Website
He, T., Zhu, M., Mills, B. J. W., Wynn, P. M., Zhuravlev, A. Y., Tostevin, R., Pogge von Strandmann, P. A. E., Yang, A., Poulton, S., and Shields, G. A., 2019. Possible links between extreme oxygen perturbations and the Cambrian radiation of animals. Nature Geoscience. Download / Website
Tostevin, R., Clarkson, M.O., Gangl, S., Shields, G.A., Wood, R.A., Bowyer, F., Penny, A.M. and Stirling, C.H., 2019. Uranium isotope evidence for an expansion of anoxia in terminal Ediacaran oceans. Earth and Planetary Science Letters, 506, pp.104-112. Download / Website
Tostevin, R., He, T., Turchyn, A. V., Wood, R. A., Penny, A. M., Bowyer, F., Antler, G. & Shields, G. A., 2017. Constraints on the late Ediacaran sulfur cycle from carbonate associated sulfate. Precambrian Research. Download / Website
Penny, A. M., Wood, R. A., Zhuravlev, A. Y., Curtis, A., Bowyer, F., Tostevin, R., 2017. Intraspecific variation in an Ediacaran skeletal metazoan: Namacalathus from the Nama Group, Namibia. Geobiology. Download / Website
Tostevin, R., Wood, R.A., Shields, G.A., Poulton, S.W., Guilbaud, R., Bowyer, F., Penny, A.M., He, T., Curtis, A., Hoffmann, K.H. and Clarkson, M.O., 2016. Low-oxygen waters limited habitable space for early animals. Nature Communications, 7. Download / Website
Tostevin, R., Shields, G. A., Tarbuck, G. M., He, T., Clarkson, M. O., & Wood, R. A., 2016. Effective use of cerium anomalies as a redox proxy in carbonate-dominated marine settings. Chemical Geology, 438, 146-162. Download / Website
Wood, R.A., Poulton, S.W., Prave, A.R., Hoffmann, K.H., Clarkson, M.O., Guilbaud, R., Lyne, J.W., Tostevin, R., Bowyer, F., Penny, A.M. and Curtis, A., 2015. Dynamic redox conditions control late Ediacaran metazoan ecosystems in the Nama Group, Namibia. Precambrian Research, 261, pp.252-271. Download / Website
Tostevin, R., Turchyn, A.V., Farquhar, J., Johnston, D.T., Eldridge, D.L., Bishop, J.K. and McIlvin, M., 2014. Multiple sulfur isotope constraints on the modern sulfur cycle. Earth and Planetary Science Letters, 396, pp.14-21. Download / Website
All data related to the Nama Group can be accessed in the NERC data repository (DOI: 10.5285/3b57c988-068d-42bb-b601-ff7ed4cabc77).