 First TecTask Field Workshop in Structural Analysis Cap de Creus (Spain) 14-19 September, 2006 Workshop leaders: - Paul Bons, Universität Tübingen, Germany
- Jordi Carreras & Elena Druguet, Universitat Autònoma de Barcelona, Spain
- Ian Alsop, University of St Andrews, UK
Contact:
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- Introduction
- Preliminary program
- Practicalities
- About the workshop leaders
- Some literature
- Pre-registration
Download the announcement flyer and pass it on to your colleagues: CdCWorkshopFlyer.pdf  1. Introduction Parc Natural de Cap de Creus, the easternmost extension of the Pyrenees, is a protected nature reserve, rich in geological, biological and archaeological heritage. The coastal cliffs and sparse vegetation provide excellent and continuous outcrops of high metamorphic grade deformation structures (Druguet 2001) and the classical retrograde shear zones for which the area is most famous (Carreras 2001). Several structures were first described from outcrops at Cap de Creus, such as sheath folds (Carreras et al. 1977), shear bands in mylonites (White et al. 1980), some of the “flanking structures” described by Passchier (2001), and the “apparent boudinage” of Bons et al. (2004). The fantastic geology and accessibility make Cap de Creus a popular destination for geological field courses.
The area forms part of the Variscan Axial Zone, the metamorphic core of the Pyrenees that experienced LP-HT metamorphism (from greenschist facies up to anatexis) during the late-Palaeozoic Variscan Orogeny. Several deformation phases affected the meta-sediments before, during and after the metamorphic peak, resulting in complex interference patterns of deformation, metamorphism and pegmatite dyke intrusion (Druguet et al. 1997). Zones of mylonite that transect the whole area developed during retrogression. Although the Alpine Orogeny significantly affected the whole Pyrenean region, its effects appear relatively minor in the Cap de Creus area. |
2. Preliminary program The aim of the workshop is to gain practical experience in the analysis of complex tectonic structures in medium- to high-grade metamorphic rocks. This is a hands-on workshop, consisting of a number of exercises, ranging from single outcrop analysis to 100 m-scale structural mapping.
The preliminary program includes the following topics
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A) Quantitative strain analysis
 |  | Strain analysis in the Roses Granodiorite
Rf/fi-analysis of stretched mafic enclaves and detailed mapping and displacement/width analysis of crosscutting shear zones to unravel the complex strain distribution in the sheared granodiorite.
| Strain analysis from deformed quartz veins in Culip
In the Puig Culip area there are sets of differently oriented and deformed quartz veins which are suitable for stretch measurements and estimations of strain. | B) Refolding & reworking during multiple deformation
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| Unraveling fold interference in multiply folded meta-sediments at Cala Rustella
Sedimentary layers have been folded at least three times. Detailed analysis of the foliations, lineations and fold axes is needed to figure out what happened. We will also see the different ways in which different rock types (marble, phyllite) react to deformation. | Mapping exercise at Mas Rabassers de Baix
Mapping of a quartzite layer in 100x300 m area will reveal three folding events, plus retrograde shearing. The quartzites host beautiful examples of rotated shear bands. | C) Refolding & reworking during progressive deformation
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| The shear zones and migmatites at Punta dels Farallons
We will visit some of the most spectacular shear zone outcrops in the area, with an abundance of all sorts of shear zone-related minor structures (e.g. sheath folds, shear bands, …). We will also see the highest-grade version of the local rocks and a variety of syntectonic intrusions and migmatites. | Boudinage or not?
Many pegmatite dykes intruded the area. They are now found as separate lenses and blocks. Are they boudinaged dykes or did they intrude like this. We will have a close look at these “pseudo-boudins”, but also at some real boudins. | Mapping at the lighthouse
With the insight gained during the previous days, you will map a small area around the lighthouse. Figure out the several deformation events, cleavages, veins and dykes, porphyroblast growth, etc. This is a very popular tourist spot: make a poster to explain the complex geology to the public | Dates
| - Arrival: Wednesday, September 13
- Workshop: Thursday, September 14 until Tuesday, September 19 (6 full days)
- Departure: Wednesday, September 20
| Getting there
| Nearest airports are at Barcelona, Girona (Spain) or Perpignan (France). Pickup from any of these airports, or nearby railway stations, on the 13th and transport back on the 20th will be provided
| Accommodation
| Accommodation will be in bungalows of the Club Carpe Diem in the town of Cadaqués. The 6-person bungalows have twin rooms (single room at extra cost), kitchen, living room, etc. Food is not included. You can cook yourself or visit the many restaurants of the tourist resort Cadaqués.
| Fitness requirements
| There are no special fitness requirements. Cap de Creus is rocky coastal area, with some steep cliffs. We will be outside all day, but only one day will involve a longer hike (2 hour one way to Punta dels Farallons). Weather can be warm and sunny, but if we have bad luck also very windy. We will do our best to accommodate any special requirements.
| Fees
| The fee for the field trip is estimated not to exceed 700 € per person. This includes accommodation (twin share rooms in bungalows, single occupancy at extra cost), transport in the field and to/from airport/railway station, and all materials. Final costs will be determined once we know the number of participants.
Note: One grant is available, specifically aimed at applicants from developing countries. Enquire with Paul Bons for how to apply.
| Background knowledge
| This workshop is aimed at postgraduate level and upwards. Knowledge of structural geology (at least undergraduate level) is expected. Professionals are of course welcome too.
| Certificate
| Participants will receive a certificate of participation. The workshop will count for 3 credits in the European Credit System.
| Other activities
| Cap de Creus is on the Costa Brava, a popular tourist destination. Highlights of the area are the Dali museum in Figueres, the historic city of Barcelona, the spectacular coast and the nearby Pyrenees. Why not combine the workshop with a holiday?
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4. About the workshop leaders 
| Paul Bons
Paul Bons is professor in structural geology at the Institute for Geosciences of Tübingen University (Germany). He spent several years as a postdoc at Monash University, Melbourne (Australia) and Mainz (Germany). His research focuses on numerical and analogue modeling of ductile deformation microstructures, formation of mineral veins and transport of fluids and magma. His field work is mainly in medium to high-metamorphic grade terrains: South Finland Migmatite Belt, Mt. Painter Inlier in South Australia, the Iberian Ranges in Spain, and, of course, Cap de Creus. He runs yearly field courses in Cap de Creus and has ongoing research interests in the area.
http://www.structural-geology.info
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Jordi Carreras
Jordi Carreras is professor in structural geology at the Department of Geology, Universitat Autònoma de Barcelona (Spain). His research focuses mainly on ductile shear zones and associated minor and microstructures. Another topic concerns the structural analysis of areas affected by polyphase tectonics involving strain localization along deformation bands. Research field areas are mainly the Variscan of central and eastern Pyrenees, with especial emphasis in the Cap de Creus. Other research areas are the Archaean Quetico Belt in Canada and the Precambrian inliers in the Anti-Atlas of Morocco. He runs yearly field courses in Cap de Creus and has ongoing research interests in the area.
http://einstein.uab.es/c_geotectonica/MIET/
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Elena Druguet
Elena Druguet is lecturer in structural geology at the Department of Geology, Universitat Autònoma de Barcelona (Spain). She did a PhD on the structural evolution of the North Cap de Creus belt. Her research focuses on structural analysis of mid to high-grade terrains, with particular attention to the interaction between tectonic, metamorphic and magmatic processes. She combines fieldwork with analogue and numerical modelling. Her current fieldwork areas are, apart from Cap de Creus and other Variscan massifs in the Pyrenees, the Archaean Quetico Belt in Canada and the Precambrian inliers in the Anti-Atlas of Morocco. She runs yearly field courses in Cap de Creus and has ongoing research interests in the area.
http://einstein.uab.es/c_geotectonica/MIET/
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| Ian Alsop
Ian Alsop is senior lecturer in structural geology, and tectonics at the School of Geography & Geosciences, University of St Andrews (UK). He has undertaken post-doctoral research at E.T.H., Zurich, Durham and London. His main research Interests (and field areas) are mid-crustal shear zones (UK, Ireland, Greenland), fold and thrust belts (Albania, Kazakhstan, Azerbaijan, Italy) and salt tectonics (Yemen, Canada). Currently he is undertaking field research in the Cap de Creus area, where he investigates the progressive development of folds in shear zones and mylonitic rocks.
http://www.st-andrews.ac.uk/gg/html/ia.html
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5. References (please contact us for reprints of some of these papers) - Bons, P.D., Druguet, E., Hamann, I., Carreras, J., Passchier, C.W. 2004. Apparent boudinage in dykes. Journal of Structural Geology 26, 625-636.
- Carreras, J., Estrada, A., White, S., 1977. The effects of folding on the c-axis fabrics of a quartz-mylonite. Tectonophysics 39, 3-24.
- Carreras, J., 2001. Zooming on Northern Cap de Creus shear zones. Journal of Structural Geology 23, 1457 – 1486.
- Carreras, J., Druguet, E., Griera, A., Soldevila, J. 2004. Strain and deformation history in a syntectonic pluton. The case of the Roses granodiorite (Cap de Creus, Eastern Pyrenees). In: Alsop, G.I., Holdsworth, R.E. (Eds.), Flow Processes in Faults and Shear Zones. Geological Society, London, Special Publications, 307-319.
- Druguet, E., Passchier, C.W., Carreras, J., Victor, P., den Brok, S., 1997. Analysis of a complex high-strain zone at Cap de Creus, Spain. Tectonophysics 280, 31-45.
- Druguet, E., 2001. Development of high thermal gradients by coeval transpression and magmatism during the Variscan orogeny: insights from the Cap de Creus (Eastern Pyrenees). Tectonophysics 332, 275 – 293.
- Passchier, C.W., 2001. Flanking structures. Journal of Structural Geology 23, 951 – 962.
- White, S., Burrows, S. E., Carreras, J., Shaw, N., Humphreys, J., 1980. On mylonites in ductile shear zones. Journal of Structural Geology 2, 175-187.
6. Pre-registration
The maximum number of participants is 24, with a minimum of 10 participants.
Admission is on a first come, first serve basis, but with a preference for MSc and PhD students
Please pre-register before July 1, 2006. The course will be cancelled if less than 10 candidates have registered by that date. We will assume that a pre-registration is binding.
Final registration and fees will be announced soon after the first of July.
To pre-register, send an email to Paul Bons (
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) and Elena Druguet (
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) with the following information
- Your name and full address, including email address
- Your academic level (BSc, MSc, PhD)
- Your current status/employment (student, academic, industry, etc.)
- A brief statement on why you want to attend the workshop
Note: One grant is available, specifically aimed at applicants from developing countries. Enquire with Paul Bons for how to apply.
Last updated 20 April, 2006.
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