Deciphering the relative roles of allogenic versus autogenic controls on deltaic depositional systems

The aim of this project is to devise a novel database-driven approach for the development of quantitative facies and sequence stratigraphic models to assess the impact of external and intrinsic controls on deltaic system development within a range of environmental settings and sedimentary basin types. Specific research objectives of this research are as follows: (i) to demonstrate evidence to show that primary allogenic and autogenic controls on preserved deltaic strata are interdependent and interrelated via a series of complex feedback mechanisms; (ii) to encapsulate facies and sequence stratigraphic models, and the data that underpin them, within a database that can be used to predict sedimentary architecture based on knowledge of system boundary conditions. The research will involve development and employment of the Shallow Marine Architecture Knowledge Store (SMAKS) and the Fluvial Architecture Knowledge Transfer System (FAKTS), two relational databases conceived and designed in the School of Earth and Environment at the University of Leeds. These databases will be used to address the following research questions.

1) What is the 3D facies architecture, internal and external heterogeneity, and connectivity of sand-bodies within fluvial-dominated delta tops subject to different climatic settings?
2) How does the geometry, connectivity and stacking pattern of distributary channel fills vary spatially and temporally within delta tops, and how well do these variations match with what is predicted by recent models that invoke backwater controls?
3) How do allogenic factors, such as climate and relative sea-level change, influence and dictate autogenic behaviour in deltaic systems, such as frequency of delta-lobe avulsion, and how are such changes manifest in the preserved stratigraphic record?
4) Are there scaling relationships between sub-components of deltaic systems that can be used predictively (e.g. mouth-bar size as a function of distributary-channel size)?
5) Are there commonalities in the way attributes (e.g. geometry, timescale) of Quaternary delta-lobes and deltaic parasequences in the ancient stratigraphic record are controlled by specific boundary conditions (e.g. accommodation: sediment-supply ratio)?
6) Is it possible to establish how the hierarchy of deltaic constructional units (e.g. lobes at multiple scales) vary as a function of the size of a delta and its controls (e.g. drainage area, mean yearly discharge)? Can such hierarchical stacking patterns be identified through analysis of bounding surface arrangements and stratal trends in ancient systems, and on drainage orders in modern systems?
7) Do we see any relationships between the direction of seismic-scale shoreline trajectories and the potential sedimentary characteristics of the different physiographic elements of a delta (top, front, prodelta)?

A range of methods will be employed to fulfil the aim of this project and answer the stated research questions. Fieldwork to examine the sedimentology and architecture of deltaic deposits accumulated in a range of basin types, and to examine the stratigraphic evolution of such systems over time. The choice of study areas and case studies is open, but could include the Jurassic of the Yorkshire coast, the Carboniferous of Ireland and Britain, or the Cenozoic in the Spanish Pyrenees. Some of these successions are exceptionally well-exposed such that they will provide excellent opportunity for field-based study to examine and document deltaic architectural heterogeneity and stratigraphic evolution. Population of SMAKS and FAKTS – two databases storing aspects of fluvial, paralic and shallow-marine stratigraphic architecture developed in-house by SMRG and FRG at Leeds – for the quantitative characterization of sedimentary units within a range of sedimentary basin types and settings. Use of satellite imagery for the collation of a database of attributes describing the plan-form morphology and scale of deltaic systems developed in a range of environmental settings and possibly associated with river-, wave- and tide-dominated seas.

Applicants should have a BSc degree (or equivalent) in geology, earth sciences, geophysics or a similar discipline. An MSc or MGeol in applied geoscience or petroleum geoscience (or similar) is desirable. Skills in field-based geological data collection and field sedimentology and stratigraphy are desirable. Experience of using GIS software would be useful, though is not essential.
The project will involve field-based data collection. There will be opportunities for the appointed applicant to spend time in the offices of our chosen project partner, Petrotechnical Data Systems (PDS), and one or more sponsor companies. Such placements will involve working with a team of applied geology professionals.