User:Daisysofia13/Ebro Basin

Article Draft

The Ebro Basin is a foreland basin which formed due to flexural subsidence in the Paleocene and is located north east of the Iberian Peninsula in Spain. The size of the basin is about 85,175 km² and is the largest river basin in Spain covering 19% of the area. Basin consists of Paleocene to Oligocene age with volcanism dating from Neogene to recent and includes faults and overthrust. The Ebro river is 928km long with a 320km² delta mouth which runs through the basin out to the Mediterranean sea. This basin shows how the surrounding mountain ranges effect each other over a period of time across the Ebro basin.

Map of Ebro surrounded by three mountain ranges

Tectonic Setting

The Ebro basin is separated from other basins by three alpine ranges: the Pyrenees which are on the north, Catalan Coastal Range on the south east and the Iberian on the southwest giving the basin a triangular shape with a focal point. These mountain ranges were used to control the growth and record tectonic events of the basin. During the late Mesozoic the European and Iberian plate collided in between France and Spain closing the Atlantic ocean passage and opening the Mediterranean which formed the Pyrenees. There are three assumptions on how the Iberian plate moved, the two assumptions that resonate the most are that the plate moved in a strike slip motion whereas the other is that the plate rotated anticlockwise.

Flexural modeling results of the Ebro basin have an effective elastic thickness of 30km in the southern and underformed parts, and the northern 11km. Basement rock thrust sheets moved North and South into the Ebro basin due to compressive stage. This basin was closed in the Oligocene and early Miocene which affected the lithospheres flexibility due to continental deposits which were later eroded by the Ebro river transporting sediments to opening of the Mediterranean sea in the late Oligocene. Development of the basin is influenced by compressional deformation, extensional tectonics, strike slip, and uplift.

Deposition history

Depositional history of the Ebro basin began during the Paleocene with half marine and half continental deposition onto unconformity of the evolving basin.

Sediment transport estimations from the Pliocene and Holocene are used for transport models due to no human activity in present. Closed basin drainage opened in the late Miocene allowing drainage out through the Mediterranean sea

Stratigraphy

stratigraphy of the Ebro basin

stratigraphy of Ebro Basin

The foreland basin is filled with lacustrine, alluvial and fluvial deposits which consist of marine, non marine and continental sediments which began accumulating in the Paleocene to Oligocene. The basins stratigraphy can be divided into three units: early Eocene which overlays the Paleozoic basement consisting of mud supported conglomerates and clay rich mud stones, middle Eocene consists of detrital and bioclastic limestone, marl and sandstone and lastly the top Oligocene consists of alternations of shale and sandstone.

The stratigraphic history is of the Ebro basin is characterized by various features, uplift, extensional tectonics, drainage opening, tectonic evolution and backfilling before and after tectonics with conglomerates, high thermal gradient and elevation. The basin has gone through different cycles and rates of sedimentation which were caused by these various features especially uplift.

Natural Resources

The Ebro river running through the basin is used for irrigation for agriculture, livestock breeding, energy production and consumption by locals.

References

1. "Management of The Ebro River Basin: Past, present and future". Water Science and Technology. 40 (10). 1999. doi:10.1016/s0273-1223(99)00672-1. ISSN 0273-1223.Garcia-Castellanos, Daniel; Vergés, Jaume; Gaspar-Escribano, Jorge; Cloetingh, Sierd (2003-07).
2. Cabal, Julia; Fernàndez, Manel (May 1995). "Heat flow and regional uplift at the north-eastern border of the Ebro basin,NE Spain". Geophysical Journal International. 121 (2): 393–403. doi:10.1111/j.1365-246x.1995.tb05720.x. ISSN 0956-540X.
3. "Interplay between tectonics, climate, and fluvial transport during the Cenozoic evolution of the Ebro Basin (NE Iberia)". Journal of Geophysical Research: Solid Earth. 108 (B7). doi:10.1029/2002jb002073. ISSN 0148-0227.
4. Vergés, Jaume; Fernàndez, Manel; Martìnez, Albert (2002). "The Pyrenean orogen: pre-, syn-, and post-collisional evolution". Journal of the Virtual Explorer. 08. doi:10.3809/jvirtex.2002.00058. ISSN 1441-8142.
5. Gaspar-Escribano, J. M.; van Wees, J. D.; ter Voorde, M.; Cloetingh, S.; Roca, E.; Cabrera, L.; Muñoz, J. A.; Ziegler, P. A.; Garcia-Castellanos, D. (2001-05). "Three-dimensional flexural modelling of the Ebro Basin�(NE Iberia)". Geophysical Journal International. 145 (2): 349–367. doi:10.1046/j.1365-246x.2001.01379.x. ISSN 0956-540X.
6. Vissers, Reinoud L.M.; van Hinsbergen, Douwe J.J.; van der Meer, Douwe G.; Spakman, Wim (June 2016). "Cretaceous slab break-off in the Pyrenees: Iberian plate kinematics in paleomagnetic and mantle reference frames". Gondwana Research. 34: 49–59. doi:10.1016/j.gr.2016.03.006.
7. Millán, H.; Bezemer, T.Den; Vergés, J.; Marzo, M.; Muñoz, J.A.; Roca, E.; Cirés, J.; Zoetemeijer, R.; Cloetingh, S.; Puigdefabregas, C. (January 1995). "Palaeo-elevation and effective elastic thickness evolution at mountain ranges: inferences from flexural modelling in the Eastern Pyrenees and Ebro Basin". Marine and Petroleum Geology. 12 (8): 917–928. doi:10.1016/0264-8172(95)98855-y. ISSN 0264-8172.