School of GeoSciences

School of GeoSciences

Earth and Planetary Science : Geodynamics

Geodynamics photo 1 (Alps)

The Group has a broad and integrated interests in the structural, stratigraphic, palaeontological and depositional history of sedimentary basins and mountain belts. Particular emphasis has been placed upon developing a better understanding of the three-dimensional architecture and the reconstruction of rift systems and deformed terranes, including the Tethyan belt of Eurasia, the North Sea and Suez Rift Systems and the suturing of the Iapetus Ocean.

Overall Objectives

This theme is concerned with research into fundamental processes that govern the working of the Solid Earth as an integrated system in space and time (ranging from small to large scale). Research in this area integrates the knowledge and theory derived from a number of sub-disciplines of the earth sciences (e.g. petrology, geophysics, structural geology, sedimentology). The work utilises state-of-the-art experimental, analytical, theoretical and modelling approaches. Researchers investigate specific processes that operate within the earth at various scales (i.e. from local field observation to the scale of mountain belts). A further objective is to use the results of such specific processes oriented studies to achieve a better understanding of how the crust as a whole is constructed and evolves as a dynamic system (e.g. the Himalayas).

Research Themes

Palaeomagnetism & palaeogeography :Orogenic Evolution : Tethyan Research : Seismic & Sequence Stratigraphy : Physical Volcanology

Palaeomagnetism and palaeogeography : Jenny Tait, Sergei Pisarevsky, Chris Rowan, Graeme Nicoll, Clare Peters & Gijs Straathof

Palaeomagnetism, the study of fossil magnetisations in ancient rocks, is the only method for quantitatively formulating and verifying pre-Mesozoic continental reconstructions. The direction of the ancient geomagnetic field, recorded during cooling in igneous and metamorphic rocks, or during deposition in sedimentary rocks, reveals the latitude and orientation of a continental block with respect to the ancient palaeomagnetic pole (palaeopole). Comparison of paleopoles and Apparent Polar Wander Paths (APWPs) from different continents enables their ancient positions, relative to the paleopole and to each other, to be determined, and reconstructions can then be checked and improved using palaeontological, geochronological, structural and other data.

Our current research is focused on the Neoproterozoic (ca. 1000 – 540 Ma) palaeogeography. There were several major glaciations during this time interval. There is a strange and important feature about these glaciations – their tracks are often found in the continents located in the equatorial palaeolatitudes. This discovery gave a rise for several interesting theories of the Precambrian climate, including the Snowball Earth hypothesis. The only way to check these theories is to recover the detailed history of the plate tectonic movement (“continental drift”) between 1000 and 540 Ma. The present palaeomagnetic database is yet unable to produce such an unequivocal drift record– data are too fragmented and often poorly dated. Few alternative palaeogeographic models exist only for some limited time intervals. Our main aim is to improve this situation by the study of several key Neoproterozoic rock formations all over the world (in Africa, Australia, North and South America, Europe, India, and Siberia). These new palaeomagnetic data will be complimented by geochronology and stable isotope studies. The expected result is an animated global plate tectonic history supplemented by the first-order palaeoclimatic reconstructions.

High Lat Paleo Mag Anim Low Lat Paleo Mag Anim

Two alternative models for the 615 – 530 Ma palaeogeography (made with the PLATES software from The University of Texas in Austin)

Palaeomagnetism group home page

Orogenic Evolution (Bottom up) : Simon Harley & Nigel Kelly

Even today few Earth Scientists appreciate that the continents, in different places and at different times in Earth history, have experienced extreme metamorphism at temperatures of over 1000oC and yet have survived the thermal shock. The resulting Ultrahigh temperature (UHT) metamorphic belts provide vital clues as to how the deep continental crust of the Earth forms and evolves in response to tectonics.

Using a combination of field, experimental and microanalytical approaches, Edinburgh geoscientists are world leaders in research into UHT and its causes. We aim to define not only the physical conditions, ages and timescales of UHT but also the complex interplay of chemical and physical processes that dictate how the hottest deep crust behaves when continents collide.

Orogenic Evolution (Top down) : Hugh Sinclair, Linda Kirsten & Mark Naylor

Research interests focus on: 1) The rates and styles of surface processes that erode mountain belts and that deposit and accumulate sediments in the surrounding sedimentary basins. 2) How these processes couple to the tectonic forcing of mountain building and sedimentary basin development, particularly that of foreland basins. 3) The differentiation of tectonic versus climatic forcing of mountain belts and their surrounding foreland basins.

Tethyan Research : A. H. F. Robertson, J.E. Dixon & J.R. Underhill

This long-standing research group is concerned with understanding the development of the Tethys Ocean system in the Alpine-Mediterranean-Himalayan areas. Current projects include:

  • Palaeozoic-Mesozoic tectonic evolution of the south margin of Eurasia in The Pontide Mountains, N Turkey
  • The Mesozoic-Tertiary tectonic evolution of microcontinents (e.g. rift, Ocean spreading, subduction, collision) in Eastern Turkey
  • Late Tertiary tectonic evolution of the southern edge of the Eurasian (Anatolian plate) exposed in Cyprus and offshore areas
  • The Tertiary tectonic evolution of the northern margin of the Arabian Plate exposed in S Turkey and N Syria.

Seismic and Sequence Stratigraphy : J.R. Underhill & R.A. Scrutton

The group's research primarily uses seismic and sequence stratigraphic methods to investigate the structure and stratigraphy of sedimentary basins. Its main aims are to further the understanding of the development and evolution of structural styles, tectonic controls on sediment dispersal and the hydrocarbon habitat of basins. Recent studies have focused upon understanding stratigraphic patterns developed in rift systems and salt-related settings in the North Sea, the Gulf of Suez, the East African Rift and the South Atlantic. Other Studies have focused upon contractional settings and inverted sedimentary basins such as the Hellenides of Western Greece and the Wessex Basin in Southern England.

The on-going PhD projects are entitled:

  • Controls on the stratigraphic architecture, depositional facies and Sediment dispersal patterns in salt-related settings
  • The long-term evolution of normal fault systems: Neogene to Recent Development of extensional structures in the Kenyan Rift, East Africa;
  • Controls on the rates of deformation and migration of the locus of extension in rift systems;
  • Controls on the structural and stratigraphic development of the Faroe-Shetland Basin

Structural Geology : Patience Cowie

The study of how faults and fractures initiate and develop using theoretical modelling and field observations. The main focus of this work is the interaction between surface processes and fault growth, in particular the response of river networks to tectonic uplift at different rates.

Physical Volcanology : Thor Thordarson

Primary focus of current research is the physical volcanology of all eruptions types within Large Igneous Provinces (LIPs) and their potential atmospheric and environmental effects. The emphasis is on field-based observations complemented by a range of laboratory studies, including standard volcanological measurements such as grain-size and clast properties as well as vesicle and crystal size distribution by image analysis, and chemical analyses by XRF, microprobe, ion-probe. The main objectives are to enhance our understanding of volcanism that characterizes LIPs through systematic studies on the lithostratigraphy of volcanic successions and eruption history as well as quantitative research on conduit processes and eruption and transport mechanisms of individual events. LIPs of interest include Iceland, Hawaii, Deccan, North Atlantic Igneous Province, and the Columbia River Plateau.

On-going PhD projects are:

  • Feeding large eruptions: crystallisation, mixing and degassing in Icelandic magma chambers
  • Eruption dynamics in subglacial phreatomagmatic eruptions: A case study of the 2004 eruption at the Grimsvotn volcano, Iceland