Crustal and lithospheric heterogeneities and their role in controlling the thermal structure of sedimentary basins: a UK case study

Overview

The project will investigate how crustal and lithospheric heterogeneities influence heat flow within the UK’s sedimentary basins. It will integrate geological and geophysical interpretations with numerical modelling to investigate the fundamental processes of heat flow and lithospheric dynamics. The project will investigate the contribution of deeper geodynamical processes as a significant control on the thermal evolution of sedimentary basins across the UK and North Atlantic. The research will further the understanding of the present day thermal structure of sedimentary basins.

Sedimentary basins are regions of the Earth’s crust dominated by subsidence and are ubiquitous spatially and temporally. The strata that fill these basins, both sedimentary and volcanic, provide insights into their formation and development, but despite several decades of research, fundamental questions remain regarding the role of deep geodynamic processes from rift initiation through to thermal subsidence. Over the past two decades the ever increasing quality and quantity of seismic reflection data has resulted in a clearer image of basins architecture. As the crust thins, the reduction in heat production causes deviations from the idealised plate models and changes the thickness of the lithosphere. It is often difficult to match models of heat flow and subsidence from sedimentary basins during and after continental breakup with well data, seismic observations and field studies. The increase in the number of temperature and heat flow measurements over the past two decades, particularly in extensional settings such as continental margins, indicates that continental lithosphere is not only marked by higher heat flow than the adjacent oceanic domains, but also by more complex controls, including crustal heterogeneity and thinning, magmatic addition, and mantle dynamics.

Understanding heat flow within sedimentary basins requires an understanding of deep geodynamic processes, however compared with oceanic lithosphere dynamics, continental lithosphere dynamics are poorly understood. This project will improve the knowledge of lithosphere dynamics in continental settings, and ultimately the evolution of plate-mantle interaction through time. This project has future applications in modelling subsurface heat flow for future energy resources, such as deep geothermal systems in sedimentary basins, and temperature predictions for deep boreholes for energy storage.

Methodology

The variations in subsurface temperatures and heat flow will be investigated through integration of geological and geophysical interpretations and numerical modelling. It will use recent data releases of both seismic reflection and well data to investigate the thermal structure of the UK onshore sedimentary basins and the UK Atlantic margins. Across the UK, in addition to industry acquired data, there are numerous deep seismic profiles acquired as part of the British Institutes Reflection Profiling Syndicate (BIRPS) and more recent studies into the broad crustal structure of the UK. It will use data from temperature and thermal data from wells to describe the variations in heat flow across the sedimentary basins. Ultimately these will be used to constrain crust and lithosphere models of their impact of heat flow perturbations through time, which could include 1D subsidence modelling, 2D flexural modelling, or numerical whole lithosphere modelling.

Through new interpretations and synthesising existing data, the project will produce a comprehensive description of crustal structure of the sedimentary basins of the UK. This interpretation will integrate the understanding gained from 1D backstripping, and use the heat flow and temperature data from >15,000 wells to describe the spatial variations in present day heat flow. The project aims to produce a suite of backstripped and forward modelled wells with a thorough understanding of the sensitives of the models as well as numerical models of heat flow which investigate the impact of lithospheric heterogeneity on predicting present day heat flow in areas of stretched continental lithosphere.

Project Timeline

Year 1

Literature review, data identification and management, training in seismic interpretation and 1D modelling, training in project specific and transferable skills, seismic and well interpretation to define crustal structure. The student will be working towards integrated geological and geophysical interpretations of crustal architecture.

Year 2

Integrated basin analysis including 1D back stripping and forward modelling, consolidate first results for academic publication. The student will work towards a suite of backstripped and forward models including an understanding of the sensitives of the models.

Year 3

Continued integration of modelling with interpretations, investigate sensitivities of modelling, consolidate results for further scientific publications (combine these with further chapters to integrate into a first draft of the PhD thesis)

Year 3.5

Completion of thesis and final submission of papers to high impact peer-reviewed journals.

Training
& Skills

Newcastle University has a faculty run postgraduate research development programme (http://www.ncl.ac.uk/sage/learningandteaching/postgraduateresearch/postgraduateresearcherdevelopmentprogramme/#creditrequirement) that follows the Vitae Researcher Development Framework (http://www.vitae.ac.uk/) focusing on: knowledge and intellectual abilities, personal effectiveness, research governance and organisation, and engagement, influence and impact. Each PhD student has a tailor made Personal Development Plan, with the expectation of them taking 60 credits in the first year and 40 credits in the second year covering both specific skills required for the project (e.g. analytical methodology, statistical analysis) and transferable skills.

The student will receive training in the interpretation and analysis of seismic reflection data and well data using industry software. They will receive training in developing numerical models of sedimentary basins.

The student will also become part of the IAPETUS DTP which offers a multidisciplinary package of training focused around meeting the specific needs and requirements of each of our students who benefit from the combined strengths and expertise that is available across our partner organisations

References & further reading

Péron-Pinvidic, G. et al. The NE Atlantic region: a reappraisal of crustal structure, tectonostratigraphy and magmatic evolution-an introduction to the NAG-TEC project. Geological Society, London, Special Publications 447, 1-10 (2017)

Petersen, K.D. et al. Mantle temperature as a control on the time scape of thermal evolution of extensional basins. Earth and Planetary Science Letters 409, 61-70 (2015)

Roberts et al., Crustal structure and heat-flow history in the UK Rockall Basin, derived from backstripping and gravity-inversion analysis. Petroleum Geoscience 25, 131-150 (2018)

Bjørlykke K. Heat Transport in Sedimentary Basins. In: Bjørlykke K. (eds) Petroleum Geoscience. Springer, Berlin, Heidelberg (2015)

Further Information

For any information on the various aspect of the PhD project, the School of Natural and Environmental Sciences, or generally doing a PhD in Newcastle, please feel free to contact Mark Ireland (mark.ireland@newcastle.ac.uk)

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