|
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. ==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. * 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Sorbas basin」の詳細全文を読む スポンサード リンク
|