Consulta: creatorFacets:"Siani, G."
Registros recuperados: 6
Data/hora: 26/07/2024 22:55:48

Deglacial and Holocene vegetation and climatic changes in the southern Central Mediterranean from a direct land-sea correlation
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Desprat, S.; Combourieu-nebout, N.; Essallami, L.; Sicre, Marie-alexandrine; Dormoy, I.; Peyron, O.; Siani, G.; Roumazeilles, V. Bout; Turon, J. L.
Despite a large number of studies, the long-term and millennial to centennial-scale climatic variability in the Mediterranean region during the last deglaciation and the Holocene is still debated, including in the southern Central Mediterranean. In this paper, we present a new marine pollen sequence (core MD04-2797CQ) from the Siculo-Tunisian Strait documenting the regional vegetation and climatic changes in the southern Central Mediterranean during the last deglaciation and the Holocene. The MD04-2797CQ marine pollen sequence shows that semi-desert plants dominated the vegetal cover in the southern Central Mediterranean between 18.2 and 12.3 ka cal BP, indicating prevailing dry conditions during the deglaciation, even during the Greenland Interstadial...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00181/29241/27634.pdf

Holocene vegetation and climate changes in the central Mediterranean inferred from a high-resolution marine pollen record (Adriatic Sea)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Combourieu-nebout, N.; Peyron, O.; Bout-roumazeilles, V.; Goring, S.; Dormoy, I.; Joannin, S.; Sadori, L.; Siani, G.; Magny, M.
The high-resolution multiproxy study of the Adriatic marine core MD 90-917 provides new insights to reconstruct vegetation and regional climate changes over the southcentral Mediterranean during the Younger Dryas (YD) and Holocene. Pollen records show the rapid forest colonization of the Italian and Balkan borderlands and the gradual installation of the Mediterranean association during the Holocene. Quantitative estimates based on pollen data provide Holocene precipitations and temperatures in the Adriatic Sea using a multi-method approach. Clay mineral ratios from the same core reflect the relative contributions of riverine (illite and smectite) and eolian (kaolinite) contributions to the site, and thus act as an additional proxy with which to evaluate...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00181/29238/27637.pdf

Hydrological changes in the Mediterranean Sea over the last 30,000 years
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Essallami, L.; Sicre, M. A.; Kallel, N.; Labeyrie, L.; Siani, G.
Sea surface temperatures were reconstructed over the last 30,000 years from alkenone paleothermometry (SST-(alk)) and planktonic foraminifera assemblages using the Modern Analog Technique (MAT) (SST-(foram)) along two cores of the Mediterranean Sea: MD84-632 (Levantine basin) and MD04-2797 (Siculo-Tunisian Strait). Oxygen isotope of planktonic foraminifera G. bulloides for core MD04-2797 and G. ruber for core MD84-632 were also determined. SST-alk in the Levantine basin indicate colder values at the Last Glacial Maximum (LGM) (similar to 14 degrees C) than earlier established from MAT, and a cooling amplitude of 6 degrees-7 degrees C, comparable to the central Mediterranean Sea. Climatic events such as the Younger Dryas (YD) and Heinrich events 1 and 2 (H1...
Tipo: Text
Palavras-chave: Paleoclimate; Glacial; Mediterranean; Alkenones; Foraminifera; Marine core.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00208/31954/30378.pdf

Paleohydrology reconstruction and Holocene climate variability in the South Adriatic Sea
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Siani, G.; Magny, M.; Paterne, M.; Debret, M.; Fontugne, M.
Holocene paleohydrology reconstruction is derived combining planktonic and benthic stable oxygen and carbon isotopes, sea surface temperatures (SSTs) and oxygen isotope composition of seawater (delta O-18(w)) from a high sedimentation core collected in the South Adriatic Sea (SAS). Core chronology is based on 10 AMS C-14 measures on planktonic foraminifera and tephra layers. Results reveal two contrasted paleohydrological periods that reflect (i) a marked lowering of delta O-18(w)/salinity during the early to mid-Holocene (11.5 ka to 6.3 ka), including the two-step sapropel S1 deposition, followed during the mid-to upper Holocene by (ii) a prevailing period of increased salinity and enhanced arid conditions in the South Adriatic Basin. Superimposed on...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00181/29204/27583.pdf

Seemingly divergent sea surface temperature proxy records in the central Mediterranean during the last deglaciation
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Sicre, Marie-alexandrine; Siani, G.; Genty, D.; Kallel, N.; Essallami, L.
Sea surface temperatures (SSTs) were reconstructed over the last 25 000 yr using alkenone paleothermometry and planktonic foraminifera assemblages from two cores of the central Mediterranean Sea: the MD04-2797 core (Siculo-Tunisian channel) and the MD90-917 core (South Adriatic Sea). Comparison of the centennial scale structure of the two temperature signals during the last deglaciation period reveals significant differences in timing and amplitude. We suggest that seasonal changes likely account for seemingly proxy record divergences during abrupt transitions from glacial to interglacial climates and for the apparent short duration of the Younger Dryas (YD) depicted by the alkenone time series, a feature that has already been stressed in earlier studies...
Tipo: Text
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00181/29201/27586.pdf

Tracking atmospheric and riverine terrigenous supplies variability during the last glacial and the Holocene in central Mediterranean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bout-roumazeilles, Viviane; Combourieu-nebout, N.; Desprat, S.; Siani, G.; Turon, J. -l.; Essallami, L.
A multiproxy study coupling mineralogical, grain size and geochemical approaches was used to tentatively retrace eolian and fluvial contributions to sedimentation in the Sicilian Tunisian Strait since the last glacial. The eolian supply is dominant over the whole interval, excepted during the sapropel Si when riverine contribution apparently became significant. Saharan contribution increased during the B011ing Allerod, evidencing the persistence of aridity over North Africa although the northern Mediterranean already experienced moister and warmer conditions. The Younger Dryas is marked by proximal dust inputs, highlighting intense regional eolian activity. A southward migration of dust provenance toward Sahel occurred at the onset of the Holocene, likely...
Tipo: Text
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00264/37574/37005.pdf