Sorbas Basin: Difference between revisions
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[[Image:Sorbas basin fill.jpg|thumb|300px|A section through the Sorbas basin. See text for explanation.]] |
[[Image:Sorbas basin fill.jpg|thumb|300px|A section through the Sorbas basin. See text for explanation.]] |
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The '''Sorbas basin''' is a [[sedimentary basin]] around the town of [[Sorbas]] in south-east [[Spain]]. It is believed to have been formed by extension, between two [[Fault (geology)|fault]]-bounded blocks which rotated anti-clockwise to take up the compression resulting from [[Europe]]'s [[Orogeny|collision]] with [[Africa]]. The basin is filled with [[turbidite]]s and [[evaporite]]s |
The '''Sorbas basin''' is a [[sedimentary basin]] around the town of [[Sorbas]] in south-east [[Spain]]. It is believed to have been formed by extension, between two [[Fault (geology)|fault]]-bounded blocks which rotated anti-clockwise to take up the compression resulting from [[Europe]]'s [[Orogeny|collision]] with [[Africa]]. The basin is filled with [[turbidite]]s and [[evaporite]]s of the [[Tortonian]]-[[Messinian]] ages of the [[Miocene]] [[Epoch (geology)|Epoch]]. |
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It is a matter of some debate whether the basin dried out at the same time as the main [[Mediterranean basin]]s.<ref name=Riding2000>{{cite journal |
It is a matter of some debate whether the basin dried out at the same time as the main [[Mediterranean basin]]s.<ref name=Riding2000>{{cite journal |
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Revision as of 02:11, 16 June 2009
The Sorbas basin is a sedimentary basin around the town of Sorbas in south-east Spain. It is believed to have been formed by extension, between two fault-bounded blocks which rotated anti-clockwise to take up the compression resulting from Europe's collision with Africa. The basin is filled with turbidites and evaporites of the Tortonian-Messinian ages of the Miocene Epoch.
It is a matter of some debate whether the basin dried out at the same time as the main Mediterranean basins.[1][2][3]
Basin fill
The basin is divided into the following members:
- At the bottom of the image, the house is constructed on the steep yellow cliffs of the resistant Azagador member.
- The lower (whiter) and upper (yellower) Abad marls, a Tortonian/Messinian series of turbidites featuring pronounced Milankovic (20,000 year precession) cyclicity, allowing chronostratigraphic dating; these fine muds are easily eroded.
- When the sea returned overdeepening the basin, salt water waterfalls eroded a 200 m depression patterned by 30 m deep gullies.[4]
- the Messinian Yesares member, a gypsum evaporite, forms the steep bluffs at the top of the valley; there is some debate about how conformable its contact with the Abad marls is.
- Pliocene deposits, rest unconformably on the top.
- Complexity of drawdown and reflooding complicate correlation of the ‘Salinity Crisis' stratigraphy.
Basin significance
*Red = current coastline *S = Sorbas basin, Spain
*R = Rifean corridor *B = Betic corridor *G = Strait of Gibraltar *M = Mediterranean sea
The basin was separated from the main Mediterranean basin during the Messinian salinity crisis; therefore the timing of the Yesares member relative to the main basin evaporites is crucial to distinguish between models of how the Mediterranean dried out.
References
- ^ Riding, R. (2000). "Late Miocene Mediterranean desiccation: topography and significance of the 'Salinity Crisis' erosion surface on-land in southeast Spain: Reply". Sedimentary Geology. 133 (3–4): 175–184. doi:10.1016/S0037-0738(00)00039-7.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Braga, J.C. (2006). "Testing models for the Messinian salinity crisis: The Messinian record in Almería, SE Spain". Sedimentary Geology. 188: 131–154. doi:10.1016/j.sedgeo.2006.03.002.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Krijgsman, W. (2001). "Astrochronology for the Messinian Sorbas basin (SE Spain) and orbital (precessional) forcing for evaporite cyclicity". Sedimentary Geology. 140 (1–2): 43–60. doi:10.1016/S0037-0738(00)00171-8.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ significance of the ‘Salinity Crisis' erosion surface on-land in southeast Spain ; Robert Ridinga, Juan C. Bragab and José M. Martín, doi:10.1016/S0037-0738(98)00115-8
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