TS
Tectonics and Structural Geology

Tectonics and Structural Geology

Introducing the people behind the TS division

This week we present the many volunteers behind the activities of the Tectonics and Structural Geology (TS) division. We can also be found on http://www.egu.eu/ts, Facebook and twitter. We are always happy to hear new ideas and feedback! Just drop a message on ts@egu.eu and don’t forget to stop by the division meeting during the General Assembly in April next year.


Susanne Buiter
President

susanneI am a senior researcher and team leader for Geodynamics at the Geological Survey of Norway and am also for 20% at the Centre for Excellence CEED at the University of Oslo. I use a model-based approach to investigate deformation processes on the scale of the upper crust to the upper mantle. These include rifted margins, sedimentary basins, thrust wedges, subduction zones, continental collision, and the entire Wilson Cycle itself.

As president for the TS division since 2013 I have tried to serve our community through a broad and hopefully exciting TS session programme at our General Assembly in Vienna. It has been great fun working closely together with all of you! Apart from geo-spamming your inbox and GA scheduling, my work also involves short courses (e.g. ERC funding or Open Access publishing), the EGU Outreach Committee (e.g., the ECS-medallist networking reception), the TS division Outstanding Early Career Scientists Award committee, tweeting division news and maintaining close ties with our sister organisations, the GSA Structural Geology and Tectonics Division and AGU Tectonophysics section.

All of this is of course only possible with the expertise help of the TS team who have been absolutely wonderful to collaborate with! I will step down at the General Assembly in April 2017 when I will take over as EGU Programme Committee chair, looking forward to that!

Personal webpage: http://www.geodynamics.no/buiter

 

Magdalena Scheck-Wenderoth – Deputy President

leniCurrently I’m a professor for basin analysis at RWTH Aachen University in joint appointment with the German Research Centre for Geosciences GFZ in Potsdam, where I lead the section basin modelling. This includes studies on the structure and dynamics of sedimentary basins on one hand and the utilization of the subsurface on the other. Therefore I work on data-based 3D lithosphere-scale to reservoir-scale basin models of sediments, crust and lithospheric mantle, coupled transport of heat and fluids in the subsurface, regional 3D gravity modelling, structural and subsidence history and salt dynamics.

As deputy president of TS I try to assist the current president Susanne Buiter where needed. As my research is focused on Geoenergy and Geodynamics of sedimentary basins, I try to make links of TS with the ERE and GD divisions aiming at avoiding overlap and making the best possible programme.

Personal webpage:

http://www.gfz-potsdam.de/en/section/basin-modeling/staff/profil/magdalena-scheck/

 

Marcel FrehnerNews & Media Officer and Webmaster

mfrehnerI am a senior scientist and lecturer (so-called “Oberassistent”) at the ETH Zurich (Switzerland) in the Group for Structural Geology and Tectonics. My main scientific interest is the mechanical investigation of geological and geophysical processes. For this, I developed various numerical modelling codes, but I also integrate my theoretical and numerical work with field and laboratory data. My process-oriented research focuses on topics in structural geology (i.e., deformation of rock units, mostly folding) and rock physics (i.e., mostly seismic properties of porous and/or fractured rocks).

Within the EGU-TS team, I am the News & Media Officer. In fact, the TS Division does not have much direct contact with media representatives, as they would contact the scientists directly. So, my job mainly involves running and feeding the TS homepage, Facebook page, and Twitter account, as well as coordinating external communication among the TS board.

Personal webpage: http://www.marcelfrehner.ch/

 

Francesca CifelliOutstanding Student Poster and PICO award coordinator

picture_cif_cropI am associate professor in structural geology at the Department of Science (Roma TRE University) in Rome, Italy. My research activity mainly focuses on palaeomagnetic studies applied to the reconstruction of the rotational history and structural evolution of curved mountain chains. Among my study areas are the Calabrian Arc, Northern Apennines, Gibraltar Arc, Central Iran, and the Central Anatolian Plateau. In Italy, I am very active in science communication and high-school teachers training.

I am a member of the EGU Committee of Education (CoE) for the organization of the GIFT (Geophysical Informations for Teachers) workshop. Within the TS team, I coordinate together with the TS President the Outstanding Student Poster and PICO (OSPP) Awards.

 

Fabrizio StortiStephan Mueller Medal Committee Chair

storti%20foto%201I have been president of the TS Division from 2009 to 2013, after serving as vice-president since 2005. Over the last four years I chaired the TS Stephan Mueller Medal committee, a role always taken by the past president of the division. From 2013 to 2016 I also chaired the EGU Topical Events Committee. So I spend more than a decade in the EGU and it is now time for me to step down and leave space to new people, with new ideas and a renewed enthusiasm. My experience in EGU is very positive because of the bottom-up philosophy that allowed me to propose ideas, strategies and improvements that contributed in some way to help the Union to constantly grow and offer higher standards, assembly after assembly, and to start playing a role much broader than the organization of congresses. I believe that dedicating some time and energy to contribute improving “our environment” as scientists and mentors is somehow dutiful, very rewarding and instructive, and so I warmly encourage all you to think about volunteering for some kind of support to the activities of the TS Division. This support includes considering the journal Solid Earth for publishing your work, help it to grow and become a well reputed, reference journal for Earth Scientists. You can find more information on publishing in Solid Earth in these two TS blogs (blogs.egu.eu/divisions/ts): Solid Earth journal: the possibilities of open access publishing and Publishing in Solid Earth: interview with Anna Rogowitz

Personal webpage: http://www.next.unipr.it/index.php/en/

 

Anne PluymakersEarly Career Scientists Representative
João DuarteEarly Career Scientists Co-Representative

anne-225x300joao-225x300

 

 

 

 

 

 

 

Read more about Anne and João, and the TS Early Career Scientists team, in the TS blog “Introducing our Early Career Scientist Team”!

 

Andrea ArgnaniProgramme Committee member for Methods and Techniques

andrea_maccalube2_2016-cropI am a Senior Scientist at the Institute of Marine Sciences of the National Research Council in Bologna, Italy. In the last 20 years, I carried out research on the tectonic evolution, kinematic reconstructions and geodynamics of the Mediterranean, with special attention to the central Mediterranean palaeogeography, the flank instability of Mount Etna, and the active tectonics of the Messina Straits, Malta Escarpment and central-southern Adriatic Sea. I started with sandbox modelling of Inversion Tectonics in Ken McClay’s laboratory at Royal Holloway (UK), and have been (much later) in charge of the Analogue Modelling Lab at the University of Parma for a couple of years.

I joined the Tectonic Division panel only recently, last year, and am supervising the Methods and Techniques sessions, with much help from Susanne.

Personal webpage: http://www.ismar.cnr.it/people/argnani-andrea?set_language=en&cl=en

 

Rebecca BellProgramme Committee member for Extensional Tectonic Settings

photo_bellI am a Lecturer in Geology and Geophysics at Imperial College London (UK) and I study tectonic evolution in a variety of settings using next generation controlled-source seismic methods and drilling data. One of my primary research interests involves understanding what factors control the geometry and evolution of continental rifts.

I am a member of the programme committee for Extensional Tectonics, which involves developing an exciting programme of sessions on rift-related topics at the EGU General Assembly.

Personal webpage:

https://www.imperial.ac.uk/people/rebecca.bell

 

Stéphane BonnetProgramme Committee member for Interplay between Tectonics and Surface Processes

photosbonnetnb-1I am Professor of Earth Sciences at the University of Toulouse (France). My research activity focus on landscape evolution and on interactions and feedbacks between tectonic, climatic and surface processes, through a combination of original laboratory-scale modelling of landscape erosion and field studies, in France, Pyrénées, Argentina, Chile, Nepal and New Zealand.

In the TS programme committee I work together with the conveners on sessions related to the interaction of tectonics with surface processes.

Personal webpage: http://www.get.obs-mip.fr/profils/Bonnet_Stephane

 

Rüdiger KillianProgramme Committee member for Brittle Deformation and Fault-related Processes and Ductile Deformation, Metamorphism and Magmatism

ruediger-cropI am a post-doc doing research and teaching in the Department of Environmental Sciences, University Basel in Switzerland. One of my main interests is the study of deformed rocks. Trying to identify the involved processes as well as quantifying their contribution based on the analysis of microstructures isn’t only incredibly exciting but might also help to improve rheological models and laboratory to nature extrapolations.

I am in the TS programme committee since 2014 taking care of “Brittle deformation and Fault-related processes” and “Ductile Deformation, Metamorphism and magmatism” which is a very interesting and instructive task. Despite at the beginning, I have sometimes wished there’d be something between “brittle” and “ductile” or no separation at all, by now I’m pretty fine with this historically grown subdivision and I hope I’ll do my job to everyone’s satisfaction; to those who send in their session proposals and we try to find a suitable place for their ideas as well as to all those people who want to find the best session for their abstract within the “brittle” or “ductile” part of our programme.

 

Olivier LacombeProgramme Committee member for Convergent Tectonic Settings

img_blog-olI am professor of tectonics and structural geology in the Institut des Sciences de la Terre de Paris (ISTeP), Université Pierre et Marie Curie (UPMC), Paris, France. My fields of interest are various, including analysis of micro/meso structures in the field and under the microscope, paleostress reconstructions, fluid-rock-tectonics interactions and tectonic evolution and mechanics of fold-and-thrust belts.

Within the TS team, I am the officer of the programme committee in charge of ‘Convergent tectonic settings’, and I am trying through years to build a complete and attractive set of sessions on the topic, in close relation to the TS division president.

Personal webpage: http://merco220.free.fr

 

Hiroki SoneProgramme Committee member for Earthquake Tectonics and Crustal Deformation

hirokiI am an assistant professor in Geological Engineering at the University of Wisconsin-Madison, USA and a visiting researcher at the German Research Centre for Geosciences GFZ in Potsdam. I work on experimental rock mechanics looking at the long-term ductile deformation of rocks at crustal depths. I apply knowledges gained in the lab to understand stress states around faults, and how they influence earthquake mechanics, and other geomechanical problems related to petroleum/geothermal reservoirs and subsurface waste management.

I have been a programme committee member for the TS team since 2015 helping organize sessions for the subdivision “Earthquake Tectonics & Crustal Deformation”.

Personal webpage: http://gle.wisc.edu/hiroki-sone-ph-d/

Publishing in Solid Earth: interview with Anna Rogowitz

Publishing in Solid Earth: interview with Anna Rogowitz

Following our previous blog about the EGU journal Solid Earth, we now would like to share some experiences of open access publishing in this journal with you. Therefore, we interviewed Anna Rogowitz, who recently published in Solid Earth, about her experiences. 

 

annaAbout Anna:

Anna is an Assistant Professor in the Structural Processes Group at the Department of Geodynamics and Sedimentology (University of Vienna, Austria) since December 2015. She finished her MSc degree in geology in the beginning of 2011 at the Institute of Geology, Mineralogy and Geophysics (Ruhr-University Bochum, Germany). Anna then carried on to a PhD in the field of structural geology with focus on strain rate dependent calcite deformation (Department of Geodynamics and Sedimentology, University of Vienna); using field observations in combination with detailed microfabric analyses to study strain localization processes in the lithosphere, with special focus on the ductile regime. Anna is also presently part of our TS ECS team.

 

1. You recently published a very interesting paper in Solid Earth. In three or four sentences, what is it about?

Thanks! The study was part of my PhD thesis in which I analysed the isotopic and mechanical impact of strain localization in a calcite marble at varying strain rates. The manuscript is dealing with the simultaneous activation of grain boundary sliding (GBS) and dislocation motion as a powerful strain softening mechanism in calcite. We analysed a pretty highly strained calcite marble and observed grain size reduction by bulging recrystallization, resulting in an almost strain-free ultramylonite that got subsequently deformed by dislocation activity, with clear evidence for GBS. The combination of these two mechanisms has been recently discussed more often for experimentally deformed rocks (Wang et al., 2010; Hansen et al., 2011). For us it was a bit surprising, as the deformation occurred at high differential stresses, relatively low temperatures and strain rates of nearly 10-9 s-1. At these conditions, brittle deformation could be anticipated rather than ductile behaviour.

 

2. Why did you choose Solid Earth?

One of the Editors, Luca Menegon (Plymouth University) was a visiting professor at our department while I was working on the study. We discussed our findings and he suggested that I submit the work to Solid Earth, as they were working on a Special Issue on ‘Deformation mechanisms and ductile strain localization in the lithosphere’ at that point. The topic of the Special Issue fit perfect to our results, so it was pretty easy to decide for Solid Earth.

 

3. Did the fact that it is an open access journal contribute to your decision?

Definitely! I like the idea of research being accessible for everybody who is interested.
I know some colleagues that have access to only a very limited number of journals. Of course there is always the possibility to write an e-mail to the author and ask for a copy of a specific manuscript but I also know that especially young researchers might be too shy or afraid to do so. Another reason for choosing an open access journal was that part of my study was funded by the Austrian Science Fund (FWF) and open access publications are mandatory.

 

4. EGU journals have a very transparent peer-review process in which reviews and author replies are posted online. How did you experience this?

I think the idea of an open review process, where people interested in a specific topic can discuss a manuscript is great. Honestly, I would have liked more people to join the discussion on our publication. I think it helps to improve the quality of a manuscript and could also help to connect people. Maybe even result in more interdisciplinary studies.

 

5. As an early career researcher, what are the most important things you look for when choosing a journal to submit a paper to?

I always go with some suggestions to my co-authors and discuss with them what would be the best choice for our manuscript. One of the most important factors for me is if it is a journal that I read regularly and preferably has open access. As an early career researcher but not that young/early anymore I have to admit that the impact factor starts to play a more important role. And of course the publication costs. I prefer to spend my funding on research and analyses than the journal I publish in.

 

6. Do you have suggestions for improvements concerning the submission, review and publication process in Solid Earth?

I thought that it was a bit time consuming that the submitted manuscript got edited as a discussion paper before it went into the review process. Also the fact that we had to pay for the preparation of the discussion paper even though it might have possibly been rejected was something I disliked. But from what I understood, these two things have been changed already. Another thing is that I would like the entire review process to be public. Of course the discussion and review process has to stop at some point but I think it would be nice if this is not before the final decision by the editor has been made. I would like that further exchanges by editor and authors could also be followed and commented on by the community.

 

7. Do you have recommendations for authors who are considering publishing in Solid Earth?

Hah! Beside ‘Go for it’… No, I really think that Solid Earth is a great journal that covers a broad field of Earth sciences. The fact that it is open access and affordable (even for early career scientists that may not have a lot of funding) is a big plus. And different to some other journals, the review process is pretty fast, which nowadays is a very important factor. Personally, I would definitely consider to submit another publication to Solid Earth. Probably, I would try to motivate a few more people to comment on the manuscript during the peer-review process. Some people have started to announce their discussion papers in the Geo-Tectonics forum, which is a very smart idea.

 

Paper’s reference:

Rogowitz, A., White, J.C., and Grasemann, B., 2016. Strain localization in ultramylonitic marbles by simultaneous activation of dislocation motion and grain boundary sliding (Syros, Greece). Solid Earth 7, 355-366, Doi:10.5194/se-7-355-2016

 

This blog was established as a group effort of the T&S team.

Minds over Methods: Experimental earthquakes

Minds over Methods: Experimental earthquakes

After our first edition of Minds over Methods, which was about Numerical Modelling, we now move to Rock Experiments! How can rock experiments be used to study processes within the Earth? We invited Giacomo Pozzi, PhD student at Durham University, to explain us how he uses rock experiments to study fault behaviour during earthquakes.

 

13072693_10207863372934990_7705005482414752149_oExperimental earthquakes to understand the weak behaviour of faults.

Giacomo Pozzi, PhD student at Durham University

As seismic slip along faults accommodates large deformations in the upper crust, the intriguing absence of significant heat flow anomalies (which are expected to be produced by intense energy dissipation during slip) along major geological bodies like the S. Andreas fault pushed the researchers to start conceiving a new, dynamic theory of friction, which eventually led to the concept of low frictional strength of faults during propagation of earthquakes.

rotary_apparatus

Fig 1. the Rotary apparatus

In the past two decades, the development of machines capable of shearing natural materials made it possible to achieve direct, experimental evidences of how friction in rocks (and gouges, when pulverised) drops from Byerlee’s values (μ=0.6-0.8) towards zero when approaching seismic velocities (>10 cm/s) and this independently of the rock composition.

However, even though a common bulk behaviour is witnessed, the weakening mechanisms that operate at the microscale are strongly dependent on the mineralogy and, despite a large amount of literature focused on this research, they are still poorly understood as their physic is an evergreen matter of debate.

My Ph.D. focuses on a weakening mechanism that has been recently proposed to occur in carbonate faults: viscous flow by grain boundary sliding, a diffusion creep dominated process particularly efficient in fine grained aggregates. In order to verify and characterise this hypothesis we try to reproduce coseismic shear conditions in pure calcite (CaCO3) gouges with a Low to High Velocity Rotary (LHVR) apparatus (Figure 1). This machine allows to simulate arbitrary amounts of slip in a thin volume of gouge, our experimental fault core, which is squeezed between two hollow cylinders. A piston located in the lower part of the apparatus lifts the lower cylinder producing an axial load (up to 25MPa) perpendicular to the plane of slip while the top cylinder spins at angular velocities up to 1500rpm (1.4 m/s tangential velocity at the reference radius).

rotary_lrDuring the experiments we record different mechanical parameters that can be processed to obtain: displacement, velocity, axial stress, shear stress, axial displacement and, with an opportune equation, the estimated temperature in the shear zone. The ratio between shear stress and axial stress gives the friction coefficient that produces a classic weakening profile when plotted against the displacement as in the graph of figure 2, where are evident two main stages: pre-weakening (μ>0.6) and weakening stage (μ<0.3).

At the end of each experiment we carefully remove the sheared sample in order to make microstructural analysis. We describe the architecture of the shear zone mainly by acquiring electron backscattered (EBS) images (figure 3) on polished sections of the samples using a scanning electron microscope. We are also planning to use cathodoluminescence and EBS diffraction to study in detail the distribution of strain, temperature and hidden geometries.

By coupling the mechanical data and the microstructural analysis of experiments stopped at different amounts of slip we are able to reconstruct the evolution of the shear zone, including the transition between a pre-weakening brittle behaviour to the steady state weakening stage where ductile-plastic processes are dominant. Understanding how the internal architecture of the shear zone changes with time and measuring its geometrical features is of paramount importance to achieve a quantitative description of the processes, which can lead to new physical laws.

With our experiments we are trying to link a qualitative description of complex natural processes and quantitative simulations based on the current physical knowledge. As a matter of fact, the obtained microstructures can be compared to natural equivalents while mechanical data and inferred laws can be implemented in numerical models.

weakening_profile

Fig 2. Weakening profile

sem_image

Fig 3. SEM BSE image of a cross section of the slip zone

Introducing our Early Career Scientist Team

This week we would like to introduce the Early Career Scientist team of Tectonics and Structural Geology community. Behind the activities organized during EGU and the year-round contacts on social media there is not only 1 single person who is responsible, but a team of people. So here you can read a bit more about each individual and their favorite type of rock science, which simultaneously showcases the entire breadth of topics covered by Tectonics and Structural Geology.

If you’re an Early Career Scientist and want to get involved too, please contact Anne Pluymakers.

 

ECS representatives

anneAnne Pluymakers

I am a post-doc at Physics of Geological Processes, or PGP, in Oslo, Norway. My background is in experimental geomechanics with emphasis on fluid-rock interactions. My current projects are mostly related to shale and CO2. Within the TS team, I am one of the two current ECS representatives. This means I coordinate the different TS activities organized by the team members, and that I also connect to the ECS representatives of the other divisions, and of course to the Division President. What I like best about working in academia is that you’re not only stuck behind a desk, but you also get to build things as well as break some rocks.

 

joaoJoão Duarte

I am an early career researcher at the Instituto Dom Luiz, University of Lisbon, Portugal, where I coordinate the marine geology and geophysics group. I work in the intersection of marine geology, tectonics and geodynamic modelling, with a special focus in the Azores-Gibraltar (Africa-Eurasia) plate boundary. My running projects cover the topics of subduction initiation and supercontinental cycles.  I am co-representative of the TS-ECS. Together with the enthusiastic team of bright ECS presented here we organize a lot of exciting activities within EGU. I am passionate about science communication and I love to share the fun of understanding the workings of the Earth with the general public.

 

The team

Blogmasters

elenoraElenora van Rijsingen

I am a PhD student in Rome and Montpellier, as part of the ITN project CREEP. I study the relationship between the roughness of subducting seafloor and seismogenic behaviour of subduction zones, by using natural data and analogue experiments. Besides that, I also really enjoy being involved in any type of outreach activities. Within the TS team, I am editor of this TS blog, together with Mehmet Köküm. This means that I write blog posts, but also invite other people to write a guest blog.  The reason I became a geologist is because I love how everything on and within the earth is connected, at scales that we humans can hardly even imagine.

 

mehmetMehmet Köküm

I am a 3rd year Phd student and Research Assistant major in Geology at Firat University in Turkey. My PhD involves fault kinematic analyses, using fault slip data obtained from fault surface. I am a field geologist and work on geological mapping, structural geology and active tectonics. I also use remote sensing techniques and digital elevation models to trace the geometry of an active fault. Within the TS team, Elenora van Rijsingen and I are the current EGU Bloggers. We work together to keep the TS Blog on the EGU website up-to-date. If you have any ideas for guest blogs, feel free to contact us!

 

Team members

subhajitSubhajit Ghosh

I am a doctoral research student at the Department of Geology, University of Calcutta in Kolkata, India. By training, I am a structural geologist at the Experimental Tectonics Laboratory (ETL). We mostly work on experimental modelling of different geodynamic and geological processes and rock deformation from micro to meso-scale. My PhD is about understanding the temporal as well as the spatial evolution of the fold-thrust belts in a collisional setting. I also use sandbox models to investigate the neo-tectonic activity of seismically active orogenic fronts. My field area is the eastern Himalaya (Darjeeling-Sikkim). Field trips in the Himalayas are evergreen and enriching for me as it renders exposures to many unknown places and with different sort of life, culture and food. Being part of the ECS-TS team is a fascinating experience; it is great to connect with so many young researchers like myself from all over the world and to become acquainted with their scientific pursuits.

 

annaAnna Rogowitz

I am currently postdoctoral researcher in the structural processes group at the Department of Geodynamics and Sedimentology (University of Vienna, Austria). My research focusses on the (broad) field of strain localization processes in the ductile regime of the lithosphere. After studying the deformation behaviour of calcite marbles for years, I decided to move a bit deeper in the Earth’s interior, and recently started a project on the rheology of eclogites. I love my job for many reasons, which I can’t possibly all list here, but the most recent one I discovered is how incredible fun it is to teach microtectonics! Within the ECS-team, I help in the organization of the ECS dinner during the EGU General Assembly. I also currently try, together with a few others, to organize a pre-EGU field trip for early career scientists.

 

anoukAnouk Beniest

I am a PhD candidate at the ‘Institut des Sciences de la Terre de Paris’, or ISTeP in Paris. I have a background in structural geology and petrology. My PhD project is about the geodynamics of rifted margins, looking at the effects of large-scale, thermal processes on basin-scale processes using a thermo-mechanical and a petroleum system model. Within the TS team, I do the ECS-Monday and jobs-on-Friday announcements on Facebook. This means that I am continuously looking for recent Tectonics/Structural Geology publications by our ECS colleagues, so if you have a publication, send it to the ECS/TS team and it might land on the page! Why did I choose to study geology in the first place? Well, I couldn’t really choose between studying physics/chemistry/mathematics, or spending the rest of my life travelling. I figured a career in geosciences could combine all of my interests. So far, I have not been disappointed and I am looking forward to the challenges and exotic places yet to come.

 

marieMarie Etchebes

I obtained my PhD in geophysics at the Institut de Physique du Globe de Paris, and followed by a post-doc at Earth Observatory of Singapore. As part of my PhD and postdoc, I have been mainly involved in understanding the geometry, kinematics and mechanics of fault systems. My main goal has been to understand how earthquake ruptures repeat through time and space along a given fault or within a fault system. To achieve this goal, I have studied quantitatively the response of geomorphic landscapes to earthquake-induced deformation. Since March 2014, I am a structural geologist at Schlumberger Stavanger Research center (Norway). My main topics cover user-guided automated technologies for fault extraction and characterization from seismic surveys; for realistic geometric and kinematic 3D fault models building;  for structural restoration and paleo-stress analysis, for geomechanical forward modeling And analysis/integration of digital outcrop analogues.

 

rolandRoland Neofitu

I am a M.Sc. student at LMU Munich. My main background lies in tectonics and structural geology. Most of my work involves the tectonics and rift propagation of the southern segments of the East African Rift.  I do this by fault mapping from DEM and satellite data, as well as by studying uplift maps. I am a recent addition to the TS team, so I hope to be able to make an active contribution to the group soon. My favorite moment as a geologist was seeing the Carboneras fault for the first time at Sopalmo, Spain. I became a geologist because of the field work that can be done at amazing places. I hope to be able to visit the East African Rift as well soon.

Soft Sediment Structures: Slumps and Flames

Soft Sediment Structures: Slumps and Flames

Today’s topic in Features of the Field is the well-known soft-sediment deformation; one of the most common phenomena which develop during, or shortly after deposition. The sediments; for this reason, need to be “liquid-like” or unsolidified for the deformation to occur. The most common places for soft-sediment deformations to form are deep water basins with turbidity currents, rivers, deltas, and shallow-marine areas with storm impacted conditions. Because these environments have high deposition rates, the sediments are allowed to be packed loosely.

Types of soft-sediment deformation structures;

Slumps; they generally occur in sandy shales and mudstones, but may also be present in limestones, sandstones, and evaporates. Thickness of slumps varies between 90 cm and 130 cm; their shapes can clearly be seen to be folds (Figure 1). Axes of these folds are horizontal or nearly horizontal (recumbent). They are a result of the displacement and movement of unconsolidated sediments in areas with steep slopes and fast sedimentation rates. Slump structures are related to tectonic activity.

Flame structures; they are mainly formed in sands, muds, and marls. The structures range from 5 to 30 cm in size (Figure 2) and are developed by mudstones which are injected into overlying sandstones. This injection is the result of large differences in dynamic viscosity between sediment layers. This makes fine-grained sediments behave as diapiric intrusions.

Soft-sediment deformation structures related to seismically induced liquefaction or fluidization are named as Seismites. Some researchers have been working on Seismites to reveal seismic history of an area.

In the field, some may define soft sediment structures as folds or something else by mistake. We should pay attention to the layers above and below these structures in order to avoid this mistake. This is because soft-sediment deformation structures are confined by non-deformed layers of the same formation.

Have fun..!

 

Figure 2. Developing of Soft Sediment Structures

Figure 2. Developing of Soft Sediment Structures

Solid Earth journal: the possibilities of open access publishing

Solid Earth journal: the possibilities of open access publishing
fabrizio-storti

Fabrizio Storti

The third blog for TS is an invited guest blog by Fabrizio Storti, the chief executive editor of the EGU journal Solid Earth. Solid Earth publishes open access manuscripts on the composition, structure, and dynamics of the Earth from the surface to the deep interior. It is the journal for our community and we encourage everyone to see if they can contribute a manuscript and/or participate in the open review process. This blog is also posted by other divisions working on solid earth themes.

 

Open access publishing in Solid Earth

graphic_se_cover_homepage

The importance of publishing open access is increasing every year in Scientific Institutions worldwide and is becoming mandatory in several research funding
programmes. Many funding institutions, including ERC, are financially supporting publishing in open access journals. EGU and Copernicus launched open access publishing in 2001, well before other publishers, and this means that we have accumulated a lot of experience with making articles available open access. But not only our journals are open access, we also have a fully open, interactive review system.

Without entering into details, which are available in the EGU portal (http://www.egu.eu/publications/open-access-journals/), the major diagnostic features are the following:

–       As soon as a manuscript is submitted, it undergoes a preliminary assessment by the relevant Executive Editor and, if found suitable for possible publication, a Topical Editor is assigned to immediately start the review process. At this stage the manuscript receives a DOI and can be cited as published in the Discussion version of the journal (the non-peer review journal).

–       The review process is open, so reviewers upload their reports in the public domain, as well as authors do with their rebuttal letters. Everybody can download manuscripts under review and upload comments, which will help authors improve their manuscripts.

Solid Earth (SE: http://www.solid-earth.net/) is the EGU open access journal in the broad area of Earth system sciences: http://www.solid-earth.net/about/aims_and_scope.html. The journal is organized into six topical clusters (http://www.solid-earth.net/), each one handled by an Executive Editor. Different types of manuscripts can be submitted: http://www.solid-earth.net/about/manuscript_types.html, including special issues, pending approval of proposals by Executive Editors.

EGU is a bottom-up union that relies on the fundamental contributions by members to organize events, first of all the Annual General Assembly.

The same approach has allowed several EGU journals to become leaders in their fields. Solid Earth is still young and, as such, it has a great potential of growing up to get established as one of the best journals in Earth system sciences. With your contribution, the journal impact factor, higher than 2.0, can significantly increase and start a virtuous loop to attract more and more good papers.

Please take few minutes of your time to browse the journal homepage (http://www.solid-earth.net/), sign in to get alerts and enjoy published papers, and think about submitting a manuscript. We are all volunteers in EGU and by supporting the self-managed, non-profit Solid Earth journal, all together we can make it one of the reference journals in Earth system sciences.

Looking forward to handle your manuscripts!

Best regards,

SE Editorial Team.

Minds over Methods: Numerical modelling

Minds over Methods: Numerical modelling

Minds over Methods is the second category of our T&S blog and is created to give you some more insights in the various research methods used in tectonics and structural geology. As a numerical modeller you might wonder sometimes how analogue modellers scale their models to nature, or maybe you would like to know more about how people use the Earth’s magnetic field to study tectonic processes. For each blog we invite an early career scientist to share the advantages and challenges of their method with us. In this way we are able to learn about methods we are not familiar with, which topics you can study using these various methods and maybe even get inspired to use a multi-disciplinary approach! This first edition of Minds over Methods deals with Numerical Modelling and is written by Anouk Beniest, PhD-student at IFP Energies Nouvelles (Paris).

 

Approaching the non-measurable

Anouk Beniest, PhD-student at IFP Energies Nouvelles, Paris

‘So, what is it that you’re investigating?’ It’s a question every scientist receives from time to time. In geosciences, the art of answering this question is to explain the rather abstract projects in normal words to the interested layman. Try this for example: “A long time ago, the South American and African Plate were stuck together, forming a massive continent, called Pangea, for many millions of years. Due to all sorts of forces, the two plates started to break apart and became separated. During this separation hot material from deep down in the earth rose to the surface increasing the temperature of the margins of the two continents. How exactly did this temperature change over time, since the separation until present-day? How did this change affect the basins along continental margins?”

These are legitimate questions and not easy to answer, since we cannot measure temperature at great depth or back in time. In this first post on numerical methods, we will be balancing between geology and geophysics, highlighting the possibilities and limits of numerical modelling.

The migration of ‘temperature’ through the lithosphere is a process that takes time and depends heavily on the scale you look at. Surface processes that affect the surface temperature can be measured and monitored, yielding interesting results on the present-day state and variations of the temperature. The influence of mantle convection cycles and radiogenic heat production are already more difficult to identify, take much more time to evolve and might not even affect the surface processes that much. Going back in time to identify a past thermal state of the earth seems almost impossible. This is where numerical models can be of use, to improve, for example, our understanding on the long-term behaviour of ‘temperature’.

Temperature is a parameter that affects and is affected by a variety of processes. When enough physical principles are combined in a numerical model, we can simulate how the temperature has evolved over time. All kinds of different parameters need to be identified and, most importantly, they need to make sense and apply to the observation or process you try to reproduce. Some of these parameters can be identified in the lab, like the density or conductivity of different rock types. Others need to be extracted from physical or geological observations or even estimated.

Once the parameters have been set, the model will calculate the thermal evolution. It is not an easy task to decide if a simulation approaches the ‘real’ history and if we can answer the questions posed above. We should always realise that thermal model results at best approach the real world. We can learn about the different ways temperature changes over time, but we should always be on the hunt to find measurements and observations that confirm what we have learned from the simulations.

temperature_quick

 

Features from the field: Slickenside Lineations

Features from the field: Slickenside Lineations

In this Tectonics and Structural Geology blog we will use different categories for our blog-posts. The first category we present to you is all about field geology: “Features from the field”. One of our bloggers, Mehmet Köküm, spends a lot of time in the field for his PhD and will share some of the features used in structural geology with us. This edition of ‘Features of the Field’ will be all about Slickenside lineations!

Paleostress Studies Reveals Deformation Mechanism 

It is assumed that faults are formed as pure strike slip or dip-slip faults. However, we widely come across oblique faults. If they are formed as pure strike-slip or dip-slip faults, then something should have affected its behavior. This can be done by many things, such as a change in tectonic regime or a block rotation. Many areas in the world have experienced several different tectonic regimes in the past. Faults should have been affected by these tectonic regime changes. A normal fault could have worked as a reverse fault in the past or vice versa. In other words, if we may figure out a faults’ past behavior, we could figure out the evolution of tectonic regimes in the related area.

Within this blog I will explain how structural geologists determine the behavior of a fault in the past and present. The principle purpose of my PhD project is to determine the deformation mechanism and the relation between past and present behavior of the East Anatolian Fault (EAF) by using paleostress analysis. The EAFZ is one of the most active intracontinental transform faults in Turkey.

During a field trip as part of my PhD project, one of the goals was to find slickenside lineation on a slip surface along the East Anatolian Fault in Turkey. Slicken-lines are series of parallel lines on a fault plane and represent the direction of relative displacement between the two blocks separated by the fault. Hence, direction and sense of slip can be obtained from slickenside lineation on a fault plane. Knowing this for numerous faults helps us to understand previous and present behavior of faults.

The aim of using slickenside lineation is to calculate the paleostress tensor. Paleostress tensors provide a dynamic interpretation (in terms of stress orientation) to the kinematic (movement) analysis of brittle features. Paleostress tensor analysis enables identification of the stress history of a studied area.

There are two principal types of slicken-lines: those that form by mechanical abrasion (striations) and those formed by mineral fibrous growth (mineral fiber lineations). The former can occur either in relief or groove on a fault surface. It can be a small quartz grain or larger grain causing striations on a fault surface. The latter developed due to crystal growth fibres or other grains being crystallized during fault slip. Most are made of calcite, quartz, gypsum etc. These two types of lineations are reliable criteria for calculating the paleostress tensor and common in low-grade metamorphic rocks and sedimentary rocks.

In this work, the key issue is to find and collect as much fault slip data sets as possible. In that sense, it is important to know what kind of rocks may include slicken-lines. Striations or slicken-lines are particularly found on limestone, sandstone and claystone. Moreover, mineral fiber lineations are seen most in limestone. Therefore, limestone should be investigated in more detail to collect fault slip data.

Paleostress studies require great care, effort, and attention in the field, but its outcomes for the behavior of the faults are important, since they reveal the tectonic evolution of the area. For this reason, many structural geologist touch on palestress studies in their work in order to relate observed structures to the causative tectonic forces.

New blog!

New blog!

We are very happy to announce that from now on, also the Tectonics and Structural Geology division will have its own EGU blog! With this blog we would like to provide a platform for exchanging thoughts and ideas within the global tectonics and structural geology community.

Here, we will write, on a monthly or fortnightly basis, about topics or techniques addressed by the many research groups that are working in fields like rheology, rock mechanics, geophysics, metamorphism, sedimentology, tectonics and neotectonics. With this we would like to provide a better link between the various different approaches and provide a more powerful understanding of deformation processes and systems. We will also share news, events, activities and job opportunities useful for the TS community.

Enjoy reading our blog posts here, and feel free to contact us any time if you want to join the team or contribute with a guest blog!

Best wishes,

The Tectonics and Structural Geology Team

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