Session programme

The idea that sedimentary basins can be compressed and uplifted – inverted – was born as early as the 1920s. However, the interest in inversion tectonics peaked in the late 1980s as documented, for instance, by a 1987 Tectonophysics special issue and a 1989 Geol. Soc. London book that soon became classics. Today few people will consider inversion tectonics a topic at the forefront of geoscience. This is not to say that nothing new can be learned about this phenomenon. Even the enormous variety of associated structures has probably not been exhaustively described and understood. The kinematics of inversion structures is particularly complex, and their mechanics a matter of debate. For instance, modelling studies have been used to suggest that reverse reactivation of normal faults can only occur in transpression, whereas studies from geologically recent cases with well-constrained stress fields do not necessarily support this observation. Inversion tectonics can coexist with or be superimposed on long-wavelength uplift that may or may not reflect a different set of processes altogether. We invite contributions dealing with all aspects of inversion tectonics from architecture over kinematics to dynamics and from field- or seismics-based case studies to analogue and numerical simulations, including also response of depositional systems to active inversion tectonics. New hypotheses challenging common wisdom are especially welcome.

Orogenic systems, including their external fold-and-thrust belts and foreland basin systems are influenced by pre-existing structures due to inherited extension, variations in thermal regime, presence or absence of evaporitic sequences, syn-tectonic sedimentation, imbrication of sub-thrust units, or climatic changes. These factors have a fundamental impact on structural styles as well as the distribution of deformation in space and time. Defining the correct structural style of fold-and-thrust belts including its uncertainty, and understanding the controlling factors are necessary steps towards predicting their long- and short-term evolution, with implications for crustal/lithospheric rheology, mountain building processes and seismic hazard, and for the correct assessment of their potential for hydrocarbon exploration. For these reasons, fold-and-thrust belts and adjacent foreland basin systems represent outstanding places to investigate (active) deformation and surface processes and the way these processes interact to shape mountain belts. On a short-time scale, the pattern of deformation of fold-and-thrust belts provides information on crustal mechanics, the sequence of active faulting and its relation to earthquakes; on a long-time scale, the structure and dynamics of the fold-and-thrust belt - foreland basin systems offers unique insights into the influence of structural, thermal and rheological inheritance, together with coupling between surface and deep processes. Thermochronology has brought new constraints on paleo-burial, exhumation and vertical movements, as well as sediment routing in fold-and-thrust belt-foreland basin systems. In addition, 2D-3D dynamic modeling by means of analog experiments and numerical simulation has been increasingly used as a tool to validate kinematic restorations and to test the influence of varying boundary conditions and material rheology on mountain building at the lithospheric scale.

This session brings together geoscientists to present and discuss multidisciplinary approaches in which a wide range of tools are integrated. We welcome contributions reporting regional case studies and their links to hinterland portions of mountain belts, as well as more topical works on structural uncertainty analysis, seismology, mechanics, temperature evolution, structural geology, geomorphology, exhumation and paleo-elevation, sediment transport and mass balance, surface processes and basin dynamics during pre- and syn-collision stages, together with analogue or numerical modeling approaches. We aim at providing a forum for all disciplines concerned with building and shaping of orogenic wedges by tectonics and climate to meet and discuss their views.

Orogenesis represents the final phase of the Wilson Cycle. As such, structural, compositional and thermal properties of the lithosphere and mantle, inherited from preceding phases can influence the evolution of the orogen. The properties and characteristics of the orogen itself can, in turn, influence post-orogenic geodynamic processes (e.g. collapse, lithospheric re-equilibration, a new extensional cycle, etc...). The Pyrenean mountain belt documents more than 300 Myrs of geodynamic history from the Variscan orogeny, followed by Mesozoic rifting, to the Alpine orogenic event. Moreover, the foreland basins around the Pyrenees provide unique records of syn-orogenic processes. Investigating these characteristics has been the motivation of several research projects over the last two decades. These projects are providing an extensive database that make the Pyrenees an ideal natural laboratory to understand the role of inheritance (thermal, structural, compositional) in rifting and orogenic processes. This session aims to bring together researchers involved in integrated studies of structural and metamorphic behaviour on all scales, basin and sedimentological analyses, numerical and analogue modelling and dating of deep to surface processes (thermochronology, geochronology, etc) as applied to the Pyrenean domain. We are particularly interested in studies that evaluate the impact of inheritance on orogenic processes at different spatio-temporal scales in the Pyrenean/Iberian realm.

This session focuses on continental collision, with an aim to understand the geodynamic processes of the subduction of rocks, continent collision and exhumation of the metamorphic core of the orogen including the subduction channel. Numerous studies of colliding continental plates show the complex interaction and feedback of processes related to the thermo-mechanical history recorded in pressure-temperature-deformation-time paths of the subducted and exhumed rocks. With modern analytical techniques, important parameters such as differential stress, strain rates, exhumation rates, kinematics, rheology, temperature and pressure can be revealed from selected rock samples from ancient and modern collision orogens such as the Alpine-Zagros-Himalayan chain, Caledonides, Variscides, or Grenville. In this session, we anticipate contributions from a broad spectrum of geoscientists, which focus on geodynamics of continent collision of ancient and recent collisional orogens.

The supercontinental cycle has profound influences on the evolution of the solid Earth, climate, and life at least since the Paleoproterozoic. Our understanding on the geodynamics of the supercontinental assembly and its link with global accretional and collisional events as well as large-scale orogenic curvatures (oroclines) remains incomplete. Here we focus on the Late Paleozoic evolution of the Pangea supercontinent, which was accompanied by a series of accretionary, collisional and orocline bending events within its core (Appalachian-Variscan-Alleghanian) and along its external boundaries (Terra Australis, Central Asian Orogenic Belt and Western Americas belts). We hope to bring new data and fresh ideas together to further understand the geodynamic link of the global orogenic evolution with the supercontinent assembly. We welcome all contributions on Late Paleozoic geology, paleomagnetism, tectonics and geodynamics.

Invited Speaker: Professor William (Bill) Collins (Curtin University)
Presentation Title: Billion year cyclicity through Earth history: causes and consequences

The session is organized in cooperation with IGCP Project 662: “Orogenic architecture and crustal growth from accretion to collision: examples from the Central Asian Orogenic Belt and Tethyan orogen”, which is supported by UNESCO-IUGS. For more information, please refer to the weblink of IGCP 662: http://igcp662.org.cn/

The Alpine-Himalayan orogenic belt is one of the largest and most prominent suture zones on Earth. The belt ranges from the Mediterranean in the west to Indonesia in the east. It results from the subduction and closing of different branches of the Tethyan Oceanic Realm and the subsequent collision of the African, Arabian and Indian continental plates with Eurasia. Its long-lasting geological record of complex interactions among major and smaller plates, featuring the presence of subduction zones at different evolutionary stages, has progressively grown as a comprehensive test site to investigate fundamental plate tectonics and geodynamic processes with multi-disciplinary studies. Advances in a variety of geophysical and geological fields provide a rich and growing set of constraints on the crust-lithosphere and mantle structure, as well as tectonics and geodynamic evolution of the entire mountain belt

We welcome contributions presenting new insights and observations derived from different perspectives like geology (stratigraphy, petrology, geochronology, geochemistry, tectonics and geomorphology), geophysics (seismicity, seismic imaging, seismic anisotropy, gravity), geodesy (GPS, InSAR), modelling (numerical and analogue), risk assessment (earthquake, volcanism), as well as from multi-disciplinary studies.

Keynote Presentations:
-Insights into the transitions in the Banda Arc-Australian continental collision from seismic imaging of deep slab structures by Meghan Miller (Australian National University)
-Active tectonics of Iran and the South Caspian: from earthquakes to
mountain-building by Richard Walker(Oxford University)

The Alps have been intensively studied by geologists for more than a century, providing a unique natural laboratory to deepen our understanding of orogenic processes and their relationship to mantle dynamics. Although most concepts that underlie current studies of mountain belts and convergence dynamics were born in the Alps, the belt is now being examined with renewed vigour in the AlpArray project. This project involves a large number of European institutions, with efforts focused on the AlpArray Seismic Network to provide homogeneous seismological coverage of the greater Alpine area at unprecedented aperture and station density, both on land and sea. New data is being recorded in a multidisciplinary research effort, and other projects are being planned in the immediate and mid-term future.
Within this context, we invite contributions from the Earth Science community that highlight new results in AlpArray and that identify and solve key open questions of the present and past structure and dynamics of the Alps and neighbouring orogens. Both disciplinary and multi-disciplinary contributions are welcome from geophysical imaging, seismotectonics, geodesy, geodynamics, gravimetry, tectonics, structural geology, petrology, geochronology, thermomechanical modelling and other allied fields. Scales of interest range from crustal to upper mantle, in the Alps and neighbouring mountain belts such as the Apennines, the Carpathians and the Dinarides.

The Arctic realm hosts vast extended continental shelves bordering old land masses, one of the largest submarine Large Igneous Provinces (LIPs) -the Alpha-Mendeleev Ridge - of Mesozoic age, and the slowest mid-ocean spreading ridge (the Gakkel Ridge) on the globe. Extreme variations in the evolution of landscapes and geology reflect the tug-of-war between the formation of new oceans, like the North Atlantic, and the destruction of older oceans: the South Anyui, Angayucham and North Pacific, which were accompanied by rifting, collision, uplift and subsidence. The causal relationships between the deep-mantle and surface processes in the Circum-Arcic region remain unclear. Geoscientific information on the relationship between the onshore geology and offshore ridges and basins in combination with variations in the mantle is the key for any deeper understanding of the entire Arctic Ocean.
This session provides a forum for discussions of a variety of problems linked to the Circum-Arctic geodynamics and aims to bring together a diversity of sub-disciplines including plate tectonics, mantle tomography, seismology, geodynamic modelling, igneous and structural geology, geophysical imaging, sedimentology, geochemistry. Particularly encouraged are papers that address lithospheric-mantle interactions in the North Atlantic, the Arctic and North Pacific regions, mantle dynamics and vertical and horizontal motion of crustal blocks and consequences for paleogeography. As geologic and tectonic models are inherently tied with changes in the oceanographic and climatic development of the Arctic, we also invite studies that focus on the interplay between these processes and across timescales. Lastly, we would like to invite contributions from studies concerning the implications of how the Arctic’s geography and geology are portrayed by modern data and issues related to jurisdiction and sovereign rights with particular focus on the UN Convention on the Law of the Sea.

Public information:
This session provides a forum for discussions of a variety of problems linked to the Circum-Arctic geodynamics and aims to bring together a diversity of sub-disciplines including plate tectonics, mantle tomography, seismology, geodynamic modelling, igneous and structural geology, geophysical imaging, sedimentology, geochemistry. As geologic and tectonic models are inherently tied with changes in the oceanographic and climatic development of the Arctic, we also show results from studies that focus on the interplay between these processes. The implications of how the Arctic’s geography and geology are portrayed by modern data and issues related to jurisdiction and sovereign rights with particular focus on the UN Convention on the Law of the Sea are also discussed.