Carbonate depositional systems at coast lines are highly sensitive to relative sea level change – caused globally and in response to local tectonics. Once calibrated, they can provide exceptional high-resolution records not only of vertical movements and tilt-rates but also of climate and oceanographic change back in geological time. These insights can in turn be taken into the subsurface to reduce uncertainty in the interpretation of subsurface stratigraphy. The challenge is to understand these responses – the aim of this PhD project. The project provides training in understanding the controls on fine-scale architecture and continuity of analogues for shallow-water carbonate reservoir rocks (and aquifers).
Uplift of the submarine thrust system of Sicily during the Plio-Quaternary is marked by a major regressive depositional system that is capped by coastal packstone carbonates that record sea-level change, modulated by local growth-folding, over c 4 million years. Spectacular parasequences exposed in cliff-sections reveal internal stratal architectures (clinoforms, top-lap and erosional surfaces, storm dune-systems) with micro-habitat variations evidenced by trace fossil assemblages and shell preservation. Existing bio and magneto-stratigraphic work shows the cyclicity relates to precession. Parasequence stacking patterns can be linked to the interplay between regional tectonic uplift, global sea-level change and local thrust-related fold amplification. Collectively the parasequences can be used to reconstruct coastal dynamics (physical and biological) and relate these not only to the tectonic history of the deforming substrate but also to high frequency (precession cycle; c 23 kyr) sea-level change. This project will build a multi-scale survey of these, using high-resolution digital mapping tools (UAV and ground-based photogrammetry) allied to sedimentological/palaeobiological fieldwork. Fieldwork will involve detailed sedimentological-structural surveys, tied to sedimentary logging and correlations. A variety of outcrop locations will provide resolution in space and time. The data will answer questions such as: how rapid is coastal migration, does it vary in time; does clinoform advance relate to top-set erosion and/or biological production; how frequent are storm events, does this vary with time within a precession cycle, and between cycles; do intra-parasequence coast-line migrations relate to their stacking patterns on active structures (which impacts on reservoir compartmentalization); are differences carbonate production (biological efficiency) related to different parts of a precession cycle? Collectively the answers will explore the coastal response to tectonics and sea-level change at high temporal resolution. The diachroneity of outcrops will show how these responses have varied through time, with applications to subsurface and palaeogeographic/temporal settings elsewhere. The project builds on qualitative studies involving RWHB and colleagues in Catania University in the 1990s in Sicily. This project will rejuvenate this collaboration, bringing high-resolution digital mapping, together with linked sedimentological and palaeobiological fieldwork, to quantify processes for the first time. Fieldwork is possible year-round. Training will be given in sequence stratigraphy, field sedimentology, UAV- and ground-based digital mapping, model-building, interpretation and visualization. The project explores the forcing of depositional systems by tectonics and climate, to improve predictions of stratal architectures in subsurface settings. Digital outcrops will be shared through existing knowledge exchange platforms.
The other supervisor on the project is Dr Agata di Stefano (University of Catania)
Candidates should have (or expect to achieve) a minimum of a UK Honours degree at 2.1 or above (or equivalent) in Geology or a relevant subject.
• Apply for Degree of Doctor of Philosophy in Geology
• State name of the lead supervisor as the Name of Proposed Supervisor
• State ‘NERC’ as Intended Source of Funding
• State the exact project title on the application form
Application closing date is 12:00pm (GMT) on 1 March 2019. Applications received after this time will NOT be considered. Additionally, incomplete applications will NOT be considered.
When applying please ensure all required documents are attached:
• All degree certificates and transcripts (Undergraduate AND Postgraduate MSc-officially translated into English where necessary)
• 2 References (Academic, where possible)
Informal inquiries can be made to Professor R Butler ([email protected]
) with a copy of your curriculum vitae and cover letter. All general enquiries should be directed to the Postgraduate Research School ([email protected]
The start date of the project is 1 October 2019