PUMA
Istituto di Scienze Marine     
Capotondi L., Vigliotti L., Bergami C. Climate and environmental changes during sapropel S1 deposition in central Mediterranean Sea. In: 13th Congress RCMNS (Naples, 2-6 September 2009). Abstract, pp. 259 - 260. INTERNATIONAL UNION OF GEOLOGICAL SCIENCES SUBCOMMISSION ON NEOGENE STRATIGRAPHY, 2009.
 
 
Abstract
(English)
Organic- rich layers, termed sapropels, characterize the Neogene stratigraphy in the Mediterranean Sea. The specific cause remain controversial, however their deposition have been related to the enhanced monsoon penetration into North Africa during precessional summer insolation maxima ( Rossignol-Strick, 1983;1985). During this time intervals, paleoceanographic investigations document increased regional precipitation with altered freshwater flows, changes in hidrology and productivity. In this study we carried out a high resolution micropaleontological, geochemical and rock magnetic analysis on a 1 m long core section (ET99-M11/IV) collected in the Jonian Sea containing an interval of about 40 cm representing the youngest sapropel layer (S1). The age-depth model has been developed by using three 14C (AMS) datings performed on planktic foraminifera tests. The results provide detailed informations about climatic conditions and marine productivity cycle occurring in the central Mediterranean Sea in the first half of the Holocene during the deposition of this anoxic layer. In particular, the quantitative distributional pattern of Neogloboquadrina pachyderma, Globigerina bulloides, Globigerinita glutinata and Globigerinoides ruber gr. shows the presence of three different environmental phases with distinctive features principally linked to the changes in stratifications of the water column and nutrient regime. The riverine imput influenced by monsoon system greatly increased at ca. 9.5 ka BP that represent the beginning of the sapropel deposition. After, environmental and oceanographic changes appears time connected to the millennial - scale climate events well-known in the North Atlantic region suggesting a mechanism link. Further studies are necessary in order to understand the relationships between monsoon regimes and north Atlantic climatic record.
Subject Sapropel, Mediterranean Sea, climate change


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