Field Seminar “Interpretation of Thrust Belts and Foreland Basins: Models from the Spanish Pyrenees”
American Association of Petroleum Geologists
Field trip leaders:
Antonio Teixell
Departament de Geologia, Universitat Autònoma de Barcelona, 08193 Bellaterra (Spain), antonio.teixell@uab.es
Antonio Barnolas
Instituto Geológico y Minero de España, C. Calera 1, 28760 Tres Cantos, Madrid (Spain), a.barnolas@igme.es
Highlights of the trip include: thrust tectonics and fault-related folding, growth folding, syntectonic turbidites, carbonate debris sheets, thrust front-proximal alluvial fan interactions, and cultural/touristic sites.
The Spanish Pyrenees provide world-class models for thrust tectonics and synorogenic sedimentation. We will examine superb outcrops of thrusts, fault-related folds, stratal architectures and facies of depositional systems affected by growing structures, which are good analogues for tectonosedimentary-related hydrocarbon plays. The trip will cover a transect of the southern Pyrenees from the Axial Zone to the Jaca piggy-back basin, a Cenozoic systrem where thrust-fold geometries are well exposed and suitable for conceptual discussion. Syn-orogenic sediments range from deep-water turbidites to shallow marine and terrestrial molasse. Turbidites include debris sheets (“megaturbidites”) that have produced gas. Older molasse sediments are perturbed by growth anticlines, and younger ones exhibit intraformational unconformities related to observable thrust faults.
The field trip takes place in beautiful mountain scenery, which is a plus to the geology. During the days of the trip, lodging will be in a comfortable hotel in the turistical/historical town of Jaca, a famous center for winter and summer leisure activities. We may additionally enjoy visits to the XI century Romanesque cathedral and the XVI century fortress, plus excursions in the surrounding area. The field excursion involves some walking in mountain terrain, always along safe and well-marked trails.
Sample Images:
1. Geological map of the field seminar area, indicating stops (stop 3.3 is out of the map area).
2. General geologic cross-section
3. Foreland basin model
4. Thrust faults at Belagua-Pierre Saint Martin (day 1).
5. View of fault-propagation folds at Aragüés (day 2).
6. View of superposed thrust ramps at Aragüés (day 2).
7. Cross-section of thrust system at Aragüés (day 2).
8. Chevron fold in deformed foreland basin turbidites.
9. Large limestone clast in submarine carbonate megabreccia (day 3).
10. View of the Mallos de Riglos at the Gallego gorge (south Pyrenean mountain front) (day 4).
Bibliography:
ALONSO, J. L. and TEIXELL, A. 1992. “Forelimb deformation in some natural examples of fault-propagation folds”. In: Thrust Tectonics (K. R. McClay, ed.). Chapman & Hall, London, 1992: 175-180.
BARNOLAS, A. and GIL-PEÑA, I., 2001. “Ejemplos de relleno sedimentario multiepisódico en una cuenca de antepaís fragmentada: la Cuenca Surpirenaica”. Boletín Geológico y Minero, 112: 17-38.
BARNOLAS, A. and TEIXELL, A. 1994. “Platform sedimentation and collapse in a carbonate-dominated margin of a turbiditic foreland basin (Eocene, Jaca basin, southern Pyrenees)”. Geology, 22: 1107-1110.
TEIXELL, A. and GARCIA-SANSEGUNDO, J. 1995. “Estructura del sector central de la Cuenca de Jaca (Pirineo central)”. Revista de la Sociedad Geológica de España, 8: 207-220.
TEIXELL, A. 1996. “The Ansó transect of the southern Pyrenees: basement and cover thrust geometries”. Journal of the Geological Society of London, 153: 301-310.
TEIXELL, A. 1998. “Crustal structure and orogenic material budget in the west-central Pyrenees”. Tectonics, 17: 395-406.
TEIXELL, A., DURNEY, D.W and ARBOLEYA, M.L. 2000 “Stress and fluid control on décollement within competent limestone”. Journal of Structural Geology, 22: 349-371.
TEIXELL, A., and KOYI, H. 2003. “Experimental and field study of the effects of lithological contrasts on thrust-related deformation”. Tectonics, 22 (5), 1051, doi: 10.1029/2002TC001460..