Overview

Project Highlights:

 

  • Address fundamental question about the response of the terrestrial and marine plants during extreme climate change
  • Fieldwork on Jurassic rocks in Morocco
  • Training in palynology, sequence stratigraphy, high-resolution analysis, palaeoclimate studies and field skills suitable for a wide range of employment

 

The Toarcian (Early Jurassic, 183 Ma) period of extreme environmental change was characterised by a 7-10°C global warming, mass extinction, eustatic sea-level rise, major perturbations to the global carbon cycle and fundamental changes to the hydrological cycle1-4. The scale of the climate change is equivalent to that predicted for 2099 under the high emission scenario of IPCC 20135 making this event a useful analogue for extreme warmth. Almost all the studies to date of this event have concentrated on mid to high latitude sections, particularly NW Europe where de-oxygenation was prevalent6 and led to the high accumulation of organic matter and the formation of an important hydrocarbon source rock. This widespread accumulation of organic matter throughout NW Europe has also led to the event being classified as an oceanic anoxic event (OAE). A key part of understanding the climate system is the low latitudes thus the little studied sediments deposited in the tropics during the Toarcian will be the focus of this study.

New low palaeolatitude sections of the Toarcian event have been located by this research group in Morocco. Our initial high-resolution stratigraphical study of these sections has identified a clear carbon-isotope excursion and the presence of climate cycles at Milankovitch frequencies as well as indications of large-scale changes in the ratio of terrestrial to marine organic matter. The proposed project will complete palynological analyses of the high-resolution samples already at the Open University to quantify the relative changes in flora and terrestrial runoff on a millennial to Milankovitch timescale during the event. These data will contribute towards a better understanding of the climate feedbacks during extreme climate change. The palynology analyses will also be combined with new field and laboratory studies along a proximal to distal depositional profile in this key palaeogeographical position in order to decipher the wider impact of the event on sedimentation and relative sea-level change.

 

Figure 1: Cyclic Toarcian strata in Morocco that will be the focus of this study. Cliff is c. 100 m high.

Methodology

 

  • Establish the changes in continental runoff on a millennium to Milankovitch scale in the tropics during the Toarcian OAE by analysing and quantifying the pollen, spores and dinoflagellates from high-resolution samples in a marine section.
  • Investigate the flora in this tropical region before during and after the event to gain a better understanding of the environment through palynological analysis.
  • Identify the changes in sedimentation due to climate fluctuations along a proximal to distal profile using sedimentological and sequence stratigraphical techniques.
  • Assess the links between changes in eustatic sea-level, climate and the flora by correlating the sequence stratigraphy of the Moroccan sections with those published from other sections around the world.
  • Understand the millennial-scale changes in sedimentation and flora in the tropics during the Toarcian OAE by integrating and synthesizing the data.

Training and Skills

In addition to a wide range of generic training from CENTA2 and the Open University, the student will be trained in a number of subject specific skills. These include high-resolution graphic logging, sample collection and preparation, sequence stratigraphy, palynology, statistics and data analysis. The successful candidate will be encouraged and supported in applying for an internship of a month or more and to take part in career-enhancing opportunities such as teaching, microfossils analysis, science communication and understanding policy.

Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training. One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.

Timeline

Year 1: Conduct fieldwork in Morocco including detailed fieldwork training with supervisors. Analyse some of the existing high-resolution samples at the OU for palynomorphs.

Year 2: Analyse data from fieldwork in Morocco. Complete palynomorph analysis. Prepare manuscript on palynomorphs. Complete 2nd field season.

Year 3: Finish interpretation and synthesis, complete sequence stratigraphical interpretation. Prepare thesis and further manuscripts. Possibly suspend PhD studies for several months to complete internship.

Partners and collaboration (including CASE)

This project will involve collaboration with Dr David Kemp (Aberdeen University/University of Geosciences, Wuhan) including the possibility of studying in China for a few weeks.

Potential CASE partner with Halliburton as this project is investigating an important hydrocarbon source rock and reservoir interval.

Further Details

Applicants should have a strong background in, and enthusiasm for field geology including the ability to work independently in the field in Morocco after initial training. In addition the student should be interested in microfossil analysis and microscope work. A driving licence is essential and a good command of French would be advantageous. The student will join a well-established team researching palaeoenvironmental change at the Open University (http://www.open.ac.uk/science/environment-earth-ecosystems/research/palaeoenvironmental-change). If you would like to apply or require further information please contact Angela Coe at the Open University (Angela.Coe@open.ac.uk).

Applications must include: