Project highlights

  • Two field seasons in Deccan Traps, India logging and studying basaltic pahoehoe flows, their volcanic features and collecting samples
  • Study the volcanic stratigraphy and flow relationships to develop a method using GIS and photogrammetry, to assess the emplacement durations of basaltic flows in large igneous provinces.
  • Geochemical analysis of collected basaltic samples to aid stratigraphic correlations as well as quantifying their compositions and gas content for assessment of environmental impacts.

Overview

The Deccan Large Igneous Province (LIP) is associated with the Cretaceous-Paleogene Boundary (KPB) mass extinction event at 66Ma. However, this is not the only environmental crisis it is linked to. Petersen et al. 2016 show a regional warming and extinction event in Antarctica and Hull et al. 2020 constrain an implied major volcanic outgassing event. Both are ~250,000 years before the KPB. Such events suggest a sustained period of large volume volcanic activity. The Thakurvadi Formation in the Kalsubai Sub-group, Deccan, is a prime candidate for this.

The Thakurvadi Fm (Fig. 1a, b) is up to 600m thick and covers ~80,000km2, although its full extent is not known. The flows of the Thakurvadi form a thick, competent part of the Western Ghats Escarpment (WGE; Fig. 1a), with very few weathering horizons. This and the welded appearance of the lobes indicate rapid emplacement with little pause between eruptions. The continuous emission of gasses could have caused the environmental effect ~250,000 years before the KPB.

This project will involve two field seasons. The first will involve logging, photogrammetry and mapping of the Thakurvadi in the WGE to recreate the 3D volcanic architecture and volcanostratigraphy of the welded lobes and establish their size and spatial relationships. Cumulatively, this allows an estimate of the time taken to emplace the entire Thakurvadi Fm. Samples will be collected and analysed using the electron microprobe and SIMS analyses of hosted melt inclusions (pockets of magma trapped in minerals) will enable their sulfur, chlorine, fluorine, carbon and water concentrations to be quantified.

The second field season will establish whether the style of the Thakurvadi continues further east and will help confirm its association with the pre-KPB environmental perturbation. Geochemical analyses (using a combination of electron microprobe, XRF and ICP-MS techniques), particularly incompatible trace elements, will be used to confirm the presence of Thakurvadi flows by comparing their chemistry with the known chemostratigraphy. The identification and interpolation of formation boundaries will help constrain the volume of the Thakurvadi Formation.

Basic modelling will be undertaken to link the new gas emissions data to the perturbations seen 250,000 years before the KPB.

Host

The Open University

Theme

  • Dynamic Earth

Supervisors

Project investigator

Co-investigators

How to apply

Methodology

The first field season will involve logging, photogrammetry and mapping of the Thakurvadi in the WGE to recreate 3D volcanic architecture and volcanostratigraphy of the welded lobes and establish their size and spatial relationships. Samples will be collected and analysed using the electron microprobe. SIMS analyses of hosted melt inclusions will enable their sulfur, chlorine, fluorine, carbon and water concentrations to be quantified.

The second field season will establish whether the style of the Thakurvadi continues further east and will help confirm its association with the pre-KPB environmental perturbation. Geochemical analyses (electron microprobe, XRF and ICP-MS), particularly incompatible trace elements, will be used to confirm the presence of Thakurvadi flows by comparing their chemistry with the known chemostratigraphy. Identification and interpolation of formation boundaries will help constrain the Thakurvadi Formation volume.

Basic modelling will be undertaken to link new gas emissions data to perturbations seen 250,000 years before the KPB.

Training and skills

Training will be given in:

  • Logging basaltic lava flows.
  • Basic surveying techniques.
  • Using GIS software for spatial modelling
  • Using photogrammetry and creating 3D images
  • Geochemical analytical techniques and data handling skills.
  • Planning and running a successful field trip.
  • The successful candidate will be encouraged to attend relevant conferences. They will also be supported in applying for a placement, and to take part in career-enhancing opportunities such as teaching, science communication and understanding policy.

Partners and collaboration

The project will collaborate with Prof. Stephen Self (University of Berkley, California) a world leading expert in the emplacement of LIPs, who will be present for at least part of the field trips. To provide expertise in India: Dr Gauri Dole (Savitribai Phule Pune University), Dr Vivek Kale at (Advanced Center for Water Resources Development and Management, Pune; India), both Deccan volcanostratigraphical experts and Dr Makarand Bodas the Deccan LIP lead at the Geological Survey of India. A placement at CASP is available and, Covid-dependent,  the possibility of a field trip to Ethiopia as field assistant to co-supervisor Dr Simon Passey.

Further details

Applicants should have a strong background in, and enthusiasm for, field geology. An interest in volcanology, detailed logging of stratigraphically sequences (any logging, volcanological is not necessary) and knowledge of GIS software (e.g. QGIS, ArcPro, ArcMap) would be advantageous.

The successful student will join a well-established team researching Dynamic Earth processes at the Open University  (http://www.open.ac.uk/science/environment-earth-ecosystems/research/dynamic_earth)

Please contact Dr Anne Jay, [email protected] for further information.

Applications should include:

  • an academic CV containing contact details of three academic references;
  • a CENTA application form, downloadable from http://centa.ac.uk/apply/how-to-apply/
  • and an Open University application form, downloadable from https://www.open.ac.uk/students/research/system/files/documents/application-form-uk.docx (UK applicants) or https://www.open.ac.uk/students/research/system/files/documents/application-form-international.docx (international applicants)

Applications must be sent to [email protected] by noon on 7th January 2022

Possible timeline

Year 1

Literature review on the Deccan Traps and Thakurvadi Fm in particular. Collate information on its current extent and exposure.  First field trip to India in January/February including detailed fieldwork training with supervisors. Analyse data from fieldwork using GIS. Start analyses on glass inclusions.

Year 2

Second Field trip to India. Attend VMSG conference. Analyse data from fieldwork including geochemistry, and write up manuscript on Emplacement of Thakurvadi Fm. Use GIS to estimate volume of the Thakurvadi Fm.

Year 3

Finish interpretation, assess impact of Thakurvadi Fm on Pre-KPB environment, prepare thesis and further manuscripts. Presentation at an international conference. Possibly suspend PhD studies for several months to complete internship.

Further reading

Hull, P. M., Bornemann, A., Penman, D. E., Henehan, M. J., Norris, R. D., Wilson, P. A., Blum, P., Alegret, L., Batenburg, S. J., Bown, P. R., Bralower, T. J., Cournede, C., Deutsch, A., Donner, B., Friedrich, O., Jehle, S., Kim, H., Kroon, D., Lippert, P. C., … Zachos, J. C. (2020). On impact and volcanism across the Cretaceous-Paleogene boundary. Science, 367(6475), 266–272. https://doi.org/10.1126/science.aay5055

Jay, A. E., Mac Niocaill, C., Widdowson, M., Self, S., & Turner, W. (2009). New palaeomagnetic data from the Mahabaleshwar Plateau, Deccan Flood Basalt Province, India: implications for the volcanostratigraphic architecture of continental flood basalt provinces. Journal of the Geological Society, 166, 13–24. https://doi.org/10.1144/0016-76492007-150

Jay, A. E., Marsh, J. S., Fluteau, F., & Courtillot, V. (2018). Emplacement of inflated Pāhoehoe flows in the Naude’s Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement. Bulletin of Volcanology, 80(2). https://doi.org/10.1007/s00445-017-1189-6

Kale, V. S., Dole, G., Shandilya, P., & Pande, K. (2019). Stratigraphy and correlations in Deccan Volcanic Province, India: Quo vadis? Geological Society of America Bulletin.

Petersen, S. V., Dutton, A., & Lohmann, K. C. (2016). End-Cretaceous extinction in Antarctica linked to both Deccan volcanism and meteorite impact via climate change. Nature Communications, 7, 9. https://doi.org/10.1038/ncomms12079

COVID-19

If Covid-19 prevents overseas fieldwork the project could study the geochemical evolution of the Thakurvadi Formation by analysing pre-existing geochemical data, new geochemical and petrographically data from existing rock samples. Or a GIS could be built to analyse pre-existing data of the Deccan. If UK field work is possible, the project could focus on the physical volcanology of the extrusives of the North Atlantic Igneous Province as a comparison with the Deccan, possibly using drones to create 3D data sets. We will work with the successful applicant to build a project that interests them.