Matches in SemOpenAlex for { <https://semopenalex.org/work/W1556585111> ?p ?o ?g. }
- W1556585111 abstract "This PhD thesis deals with the study of Messinian marine deposits from the Montemayor-1 core that is located closed to Huelva (SW Spain) at the northwestern margin of the lower Guadalquivir Basin. The core ranges from the latest Tortonian (late Miocene) to the early Zanclean (early Pliocene in age), thus including marine sediments coetaneous to the interval before, during and after the Mediterranean Messinian salinity crisis (MSC). The accuracy of the magnetobiostratigraphic age model proposed for the core has been improved using oxygen stable isotopes that have allowed the identification of the Messinian glacial-interglacial cycles (TG?s cycles) based on astronomical tuning. In this thesis, the paleoenvironmental evolution of these Messinian sediments, as well as changes in paleoceanographic circulation and paleoproductivity in the NE Atlantic have been studied using benthic foraminiferal assemblages and oxygen and carbon stable isotopes.Changes in the benthic foraminiferal assemblages along the Montemayor-1 core show a transgressive-regressive trend. A sharp sea-level rise from the inner-middle shelf to the middle slope took place during the latest Tortonian-earliest Messinian. Sea level then dropped from the middle slope to the inner-middle shelf during the early Messinian-early Pliocene. Other key factors controlling the distribution of the benthic foraminifera, in addition to sea-level variations, were the quantity and the quality of the organic matter that reached the sea floor. The inner-middle shelf was a eutrophic setting with very low oxygenation and high input of degraded continental organic matter derived from river run-off. The outer shelf and the shelf edge were oligotrophic environments with high oxygenation. In the outer shelf, organic matter supply was mostly due to riverine discharge. Finally, mesotrophic conditions with moderate oxygenation prevailed in the upper and middle slope settings, where upwelling currents supplied marine fresh organic matter to the sea floor.The paleogeographic position of the Montemayor-1 core close to the last Betic seaway to be closed, the Guadalhorce Corridor, is crucial to the study of the impact of the Mediterranean outflow water (MOW) on the eastern Atlantic oceanography. The improved age model suggests that the closure of the Guadalhorce Corridor occurred at 6.18 Ma. Oxygen stable isotopes indicate that the study area was bathed by the MOW up to the closure of the Guadalhorce Corridor. When the MOW was interrupted, only Atlantic upwelled water (AUW) reached the study area. The cessation of the MOW reduced the formation of North Atlantic deep water (NADW) and, consequently, weakened the Atlantic meridional overturning circulation (AMOC) and promoted cooling in the northern hemisphere. Furthermore, the AMOC was weak during glacial periods but strong during interglacials. In the earliest Pliocene, the opening of the Strait of Gibraltar increased the NADW promoting a stronger AMOC.Stable isotopic records and high-productivity target taxa have revealed that glacioeustatic fluctuations exerted a significant control on the paleoproductivity in the lower Guadalquivir Basin during the Messinian. Under glacial conditions, there was high productivity related to the supply of fresh organic matter from upwelling currents induced by strong winds. In contrast, interglacial periods are characterised by the presence of marine degraded organic matter in the upper slope after upwelling events, and supply of continental degraded organic matter in the outer shelf derived from riverine discharge.The detailed study of the paleoenvironmental and paleoceanographic changes throughout the core provides support for a new model for the onset and end of the MSC. This model suggests that glacioeustatic sea-level fall with only a minor contribution of tectonic uplift provoked initiation of the MSC. The marine reflooding of the Mediterranean, which marks the end of the MSC occurred in two-steps: 1) glacioeustatic sea-level rise during interglacial stage TG 11 (5.52 Ma) allowed relatively warm Atlantic waters to at least enter the western-central Mediterranean; and 2) the opening of the Strait of Gibraltar at the lowermost Pliocene caused the final refilling of the entire Mediterranean Sea." @default.
- W1556585111 created "2016-06-24" @default.
- W1556585111 creator A5002209441 @default.
- W1556585111 creator A5011725812 @default.
- W1556585111 date "2013-04-24" @default.
- W1556585111 modified "2023-09-23" @default.
- W1556585111 title "Paleoecological and paleoceanographical study of messinian depostis from the lower Guadalquivir basin (SW Spain)" @default.
- W1556585111 cites W106350592 @default.
- W1556585111 cites W140666106 @default.
- W1556585111 cites W1496478109 @default.
- W1556585111 cites W1500324428 @default.
- W1556585111 cites W1536558864 @default.
- W1556585111 cites W1543973628 @default.
- W1556585111 cites W1554362723 @default.
- W1556585111 cites W1559833754 @default.
- W1556585111 cites W1574448559 @default.
- W1556585111 cites W1581594313 @default.
- W1556585111 cites W1604687641 @default.
- W1556585111 cites W163314159 @default.
- W1556585111 cites W1654317788 @default.
- W1556585111 cites W1672397382 @default.
- W1556585111 cites W1841674799 @default.
- W1556585111 cites W186617052 @default.
- W1556585111 cites W1912899300 @default.
- W1556585111 cites W1930435662 @default.
- W1556585111 cites W1951931215 @default.
- W1556585111 cites W1964202969 @default.
- W1556585111 cites W1968860571 @default.
- W1556585111 cites W1970242906 @default.
- W1556585111 cites W1971001423 @default.
- W1556585111 cites W1971369540 @default.
- W1556585111 cites W1974479175 @default.
- W1556585111 cites W1975341354 @default.
- W1556585111 cites W1976550053 @default.
- W1556585111 cites W1977537427 @default.
- W1556585111 cites W1978579405 @default.
- W1556585111 cites W1979257792 @default.
- W1556585111 cites W1979971423 @default.
- W1556585111 cites W1980051883 @default.
- W1556585111 cites W1981818426 @default.
- W1556585111 cites W1982540125 @default.
- W1556585111 cites W1982574037 @default.
- W1556585111 cites W1983023155 @default.
- W1556585111 cites W1983045649 @default.
- W1556585111 cites W1983852332 @default.
- W1556585111 cites W1984661663 @default.
- W1556585111 cites W1985578347 @default.
- W1556585111 cites W1987501704 @default.
- W1556585111 cites W1988227476 @default.
- W1556585111 cites W1989894595 @default.
- W1556585111 cites W1991089631 @default.
- W1556585111 cites W1993497033 @default.
- W1556585111 cites W1994562053 @default.
- W1556585111 cites W1994846573 @default.
- W1556585111 cites W1995702444 @default.
- W1556585111 cites W1996999256 @default.
- W1556585111 cites W1997252211 @default.
- W1556585111 cites W1997735132 @default.
- W1556585111 cites W1999176036 @default.
- W1556585111 cites W2000055654 @default.
- W1556585111 cites W2000650363 @default.
- W1556585111 cites W2000730464 @default.
- W1556585111 cites W2003132248 @default.
- W1556585111 cites W2003846368 @default.
- W1556585111 cites W2003961310 @default.
- W1556585111 cites W2009429119 @default.
- W1556585111 cites W2010958723 @default.
- W1556585111 cites W2010968426 @default.
- W1556585111 cites W2012006566 @default.
- W1556585111 cites W2013686371 @default.
- W1556585111 cites W2014814321 @default.
- W1556585111 cites W2015708493 @default.
- W1556585111 cites W2016225258 @default.
- W1556585111 cites W2016737438 @default.
- W1556585111 cites W2017644884 @default.
- W1556585111 cites W2017706526 @default.
- W1556585111 cites W2021984838 @default.
- W1556585111 cites W2024147492 @default.
- W1556585111 cites W2028847702 @default.
- W1556585111 cites W2028921645 @default.
- W1556585111 cites W2031655227 @default.
- W1556585111 cites W2032716480 @default.
- W1556585111 cites W2033538907 @default.
- W1556585111 cites W2034612406 @default.
- W1556585111 cites W2034649511 @default.
- W1556585111 cites W2035241110 @default.
- W1556585111 cites W2035775487 @default.
- W1556585111 cites W2036350634 @default.
- W1556585111 cites W2038095701 @default.
- W1556585111 cites W2039455189 @default.
- W1556585111 cites W2041382224 @default.
- W1556585111 cites W2041834603 @default.
- W1556585111 cites W2041911154 @default.
- W1556585111 cites W2043958054 @default.
- W1556585111 cites W2044092430 @default.
- W1556585111 cites W2044636075 @default.
- W1556585111 cites W2045133665 @default.
- W1556585111 cites W2047572860 @default.
- W1556585111 cites W2048058291 @default.
- W1556585111 cites W2049556736 @default.