Imaggeo on Mondays: Marble outcrops

29 Sep

This week’s Imaggeo on Mondays image was taken by Prof. Konstantinos Kourtidis, in Alykes, along the southern coast of Thassos island, where he photographed the beautifully white marbles that outcrop along the coastline. The Greek Island of Thassos is located in northeastern Greece, close to the coast of Thrace in the Aegean Sea, although geographically it belongs to the Macedonia region. There is geological evidence to suggest that at one time, the island was joined to the mainland.

Marble Outcrops. (Credit: Konstantinos Kourtidis via

Marble Outcrops. (Credit: Konstantinos Kourtidis via

“The island is formed of alternating marbles, gneisses and schists” explains Konstantinos, “in the southern Thassos area, where this image was taken, Palaeozoic (around 400 million years in age) and Mesozoic metamorphosed rocks of the Rhodopi Massif and more recent sedimentary Miocene formations (around 25 million years old) are exposed.” The sediments in this area are dominated by conglomerates, sandstones and argillaceous sands.

Banded iron formations, also known as BIFs, are repeated thin layers of iron-rich material which are alternated with shales and/or silica rich cherts. There are numerous occurrences of BIFs across Thassos island and this is interesting because BIFs are typical sediments of the Precambrian rock record and can indicate the presence of rocks which are in excess of 3 billion years old! It is unusual to find BIFs in the younger rocks record. On Thassos Island their formation is associated with changes in the depositional environment and climate.

During the formation of BIFs, volcano-sedimentary units become heavily mineralised and rich in iron and manganese oxides. In addition the island has dense accumulations of zinc and lead. As a result there is a long mining history on Thassos, dating back to 13,000 BC. The marbles seen in today’s Imaggeo on Mondays image belong to an ancient mine at sea level which was “exploited given the excellent quality of the marbles” states Konstantinos. The stone has been used in art projects, monuments and the building of numerous ancient temples.

Ancient Marble Quarry in Thassos, Eastern Macedonia, Greece. (Credit: Konstantinos Kourtidis via

Ancient marble quarry in Thassos, Eastern Macedonia, Greece. (Credit: Ioannis Daglis via

Given the islands rich archeological and geological heritage the Greek Institute of Geology and Mineral Exploration (IGME) has produced a geological guide for the southern part of the island, which also includes 4 geotrails and is available online.

GeoEd: Under review

26 Sep

In this month’s GeoEd column, Sam Illingworth tells us about how teaching undergraduate students about peer review can help eliminate bad practice.

To anybody other than a researcher, the words peer review might seem like a fancy new age management technique, but to scientists it is either the last bastion of defence against the dark arts or an unnecessary evil that purports to ruin our greatest and most significant works.

According to Wikipedia (itself a fine proponent), peer review is defined as “the evaluation of work by one or more people of similar competence to the producers of the work (peers). It constitutes a form of self-regulation by qualified members of a profession within the relevant field.”

Peer review itself is not a new concept; the first documented description of a peer-review process, being found in the ‘Ethics of the Physician’ by Ishap bin Ali Al Rahwi (854–931), states that the notes of physicians were examined by their contemporaries to assess if treatment had been performed according to the expected standards (you can read more on the history of the peer-review process in this article).

Even the great Carl Sagan found the critique of his work difficult to stomach (Photo credit: NASA JPL, via Wikimedia Commons).

Even the great Carl Sagan found the critique of his work difficult to stomach (Photo credit: NASA JPL, via Wikimedia Commons).

“Why do we put up with it? Do we like to be criticized? No, no scientist enjoys it.” So sayeth American cosmologist and author Carl Sagan about the ‘joys’ of peer review, in his book ‘The Demon-Haunted World: Science as a Candle in the Dark.’ He goes on to say that “Every scientist feels a proprietary affection for his or her ideas and findings. Even so… the hard but just rule is that if the ideas don’t work, you must throw them away.”

Just reading these words brings me out in the kind of cold sweat that I normally associate with seeing the bill from mechanic, after having your car serviced. You know that you are going to have to bite the bullet, but in your heart of hearts you just wish that it weren’t so.

Love it or loathe it the peer-review system is an integral part of being a researcher, and given its prevalence it is strange that for many scientists the whole notion of it is a completely alien concept until they first encounter the publication process during their postgraduate studies.

During the first year of my PhD I remember being aghast at the notion that two, or possibly three, strangers would be wholly responsible for deciding whether or not my research was deemed ‘suitable’ for publication, and despite my otherwise excellent undergraduate education I had nothing to prepare me for the whole ordeal. Thankfully I had a very experienced supervisor who was able to guide me through the whole process and teach me a few tricks of the trade (always respond politely, compliment the reviewer for their suggestions, avoid the urge to break down into tears and instead break the comments down into manageable chunks), but even now I still feel a sense of dread when an email notification appears in my inbox telling me that “the reviewer’s comments have been posted.”

Is this how reviewers are perceived? (Photo credit: deviantArt)

Is this how reviewers are perceived? (Photo credit: deviantArt)

By nature I am quite a defensive person, and have been known to take criticism (fair or otherwise) rather to heart, but my experiences of the peer review system have certainly helped me take a more level–headed and professional approach to the critique of my work. Crucially it has also helped me to become a better reviewer myself.

Constructive criticism is essential in order to help one develop as a researcher, and indeed as an individual, but some of the peer reviews that I have seen (and sadly been subjected to) are nothing more than mean-spirited attempts by the reviewer to assert their own supposed authority on a subject. This kind of analysis is beneficial to absolutely no one, and it should be the responsibility of the editors and administrative staff of the journals and e-zines to help eradicate it. There is always something positive to be said about any piece of research (unless it is utterly nonsensical, in which case again the editor should have stopped it from ever being submitted to a reviewer), and being totally negative in your comments will only serve as fuel for a vicious cycle in which young researchers believe that the purpose of peer review is to find fault in the work of others. Instead, good peer review should be a helpful critique of a fellow colleagues work, which politely points out any shortcomings, makes suggestions for improvements, and praises what is good.

I will now be teaching my own university students about the peer-review system, and will be asking them to mark one another’s work throughout the unit that I teach on Science Communication at Manchester Metropolitan University. I think that most undergraduate courses would benefit from a similar approach, not only to prepare future scientists, but also to help students learn how to respond to criticism and how to critique the work of others in a productive and conducive manner. By educating and encouraging young scientists in this way we can hope to potentially avoid these kinds of reactions in the future.

Teaching about peer review at university can help to eliminate bad practice (Photo credit: Gideon Burton).

Teaching about peer review at university can help to eliminate bad practice (Photo credit: Gideon Burton).

For those of you who are currently reviewing a paper, I set you the challenge of explicitly writing at least one compliment to the author. This could be in regards to the excellence or originality of their research, the structure or fluidity of the article, or indeed the clarity with which they express their ideas. To those of you who are not reviewing a paper, try and find at least one positive thing to say (the colour really brings out your eyes, it’s certainly an affordable mode of transport, these scones are delicious!) the next time that your opinion is required; I guarantee that it will leave everyone feeling just a little bit more capable of themselves and what they can achieve.

 By Sam Illingworth, Lecturer, Manchester Metropolitan University

Apply now to take part in the 2015 GIFT workshop!

24 Sep

The General Assembly is not only for researchers but for teachers and educators with an interest in the geosciences also. Every year the Geosciences Information For Teachers (GIFT) is organised by the EGU Committee on Education to bring first class science closer to primary and high school teachers. The topic of the 2015 edition of GIFT is mineral resources and will be taking place on April 13–15 at the EGU General Assembly in Vienna, Austria.

The workshop will explore one of the most important challenges faced by modern society: access to raw materials, including base and strategic minerals, in a rapidly developing and growing world.

Mineral resources, the theme for this years GIFT workshop at the General Assembly

Mineral resources, the theme for this year’s GIFT workshop at the General Assembly

Teachers from Europe and around the world can apply to participate in the 2015 edition of GIFT, and to receive a travel and accommodation stipend to attend the workshop, by November 28. Application information is available for download in PDF format, a document which also includes the preliminary programme of the workshop.

Not sure what to expect? More information about GIFT workshops can be found in the GIFT section of the EGU website. You can also take a look at the post about the 2014 workshop at the GA and at some videos of the workshop videos from 2013.

Imaggeo on Mondays: The Final Effort

22 Sep

We’ve all been there: long hours in the field, a task that seems never ending but which has to be finished today. This week’s Imaggeo on Mondays image is brought to you by Patrick Klenk who highlights the importance of how ‘getting the job done’ relies on good team work!

Two years ago I posted this picture to imaggeo as a tribute to everyone who ever experienced the perils and pitfalls of outdoor field experiments and especially to the colleagues who help you to pull through in the end. It is their scientific spirit which allows to add that indispensable calibration measurement making the difference between a heap of nice-to-look-at data and a quantifiable dataset — even if this means staying on for that extra hour in quickly fading daylight while the cold of a late autumn night encroaches already relentlessly upon your exposed field site.

Final Effort (Credit: Patrick Klenk via

Final Effort (Credit: Patrick Klenk via

In this particular case, we started out on a bright late autumn day, planning to quickly complete a week-long series of Ground-Penetrating Radar  (GPR) experiments on our ASSESS test site in the vicinity of Heidelberg, Germany.  Most certainly, we intended to be finished long before this picture was taken — but alas, as most environmental scientists who are concerned with experimental field studies can probably relate to, outdoor experiments often do not work out exactly as planned and especially timetables get overturned more often than not. In the end, this field day turned out to be the last usable field day for that season and only through the final team effort pictured here we were able to successfully complete a quite involved series of GPR experiments.

The aim of these GPR experiments is to quantify near-surface soil hydraulic properties through the observation of soil water dynamics with non-invasive measurement methods directly at the field scale.  To date, the quantification of soil hydraulic properties remain the holy grail of soil sciences, since they are difficult to determine but widely required for a range of applications such as precision agriculture or the prediction of contaminant flow through the subsurface. Traditional approaches, which determine soil hydraulic properties e.g. from soil samples in the laboratory, suffer from their high cost, their destructive nature and from issues of transferability of the results back to the field. We specifically designed our test-site with a complicated but known subsurface structure to allow for the development of quantitative, high-resolution observations of soil water dynamics with GPR.  In brief, our approach compares GPR observations of soil water dynamics related processes such as: water sprinkling from above the surface (infiltration) or a varying water table depth (achieved by pumping water in and out of the structure from below: imbibition and drainage) to numerical simulations of both subsurface water flow and the expected GPR response. Our research then focuses (i) on observation based estimation methods of the parameters which are needed by the models we use to calculate physical property distributions (inversion) and (ii) on data assimilation methods (i.e. a form of continuously integrating modelled states of a physical system with available observational data) to optimally combine all available information for quantifying the soil properties in question.


Patrick is a physicist, currently working as a postdoc with the soil physics group at the Institute of Environmental Physics, Heidelberg University, Germany, on novel approaches for developing Ground-Penetrating radar for quantitative soil hydrology.


By Patrick Klenk, postdoctoral researcher at the Institute of Environmental Physics, Heidelberg University, Germany



Buchner, J.S., Wollschläger U., Roth K. (2012), Inverting surface GPR data using FDTD simulation and automatic detection of reflections to estimate subsurface water content and geometry, Geophysics, 77, H45-H55, doi:10.1190/geo2011-0467.1.

Dagenbach, A., J. S. Buchner, P. Klenk, and K. Roth (2013), Identifying a soil hydraulic parameterisation from on-ground GPR time lapse measurements of a pumping experiment, Hydrol. Earth Syst. Sci., 17(2), 611–618,doi:10.5194/hess-17-611-2013.

Klenk, P., Jaumann, S., and Roth, K. (2014): Current limits for high precision GPR measurements, in ‘Proc. 15th International Conference on Ground Penetrating Radar (GPR2014), 30 June-04 July 2014, Brussels, Belgium, available online shortly.

Klenk, Patrick,  Developing Ground-Penetrating Radar for Quantitative Soil Hydrology, PhD-Thesis, Heidelberg University, 2012,


Imaggeo is the EGU’s open access geosciences image repository. Photos uploaded to Imaggeo can be used by scientists, the press and the public provided the original author is credited. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. You can submit your photos here.




Get every new post on this blog delivered to your Inbox.

Join other followers: