| Text | 142700 2010 crater lakes climate sediment Holocene Pleistocene Reconstructing natural and human induced environmental change in central Italy since the late Pleistocene The multi proxy records from maar lakes Albano and Nemi Vigliotti, L. 1 , D. Ariztegui 2 , A. Lami 3 P. Guilizzoni 3 1 CNR ISMAR, Istituto di Scienze Marine, Via Gobetti 101, 40129 Bologna 2 Section of Earth and Environmental Sciences, University of Geneva, Rue des Mara1chers 13, 1205 Geneva, Switzerland 3 CNR ISE, Verbania Following the final phase of Pleistocene volcanism in the Latium region, the main craters of Albano and Nemi in the Colli Albani volcano started to accommodate a sedimentary sequence in both lakes of variable thickness. In the mid 1990s, an EU funded interdisciplinary project PALICLAS investigated the palaeoenvironmental record of the sedimentary sequences of Lakes Albano and Nemi using a multi proxy approach. A set of up to 14 m long cores was recovered from the two maar lakes following a seismic survey. Detailed petrophysical magnetic , sedimentological and geochemical analyses, combined with a large palaeoecological dataset including algal and bacterial pigments, biological remains such as pollen, diatoms, Cladocera, chir onomids and ostracods were carried out in three selected sites in Lake Albano and one site in Lake Nemi. A robust chronology was established by integrating accelerator mass spectrometry AMS radiocarbon datings, pollen analysis and secular variation record of the magnetic field together with the identification of two tephra layers correlated with the Late Pleistocene Etnean eruption of Bian cavilla Y1; 17.2 cal ka BP and the late Holocene Pomici di Avellino 4.1 cal ka BP . The com piled results of these investigations provide a detailed chronicle of the response of both lacustrine basins to climate and anthropogenically triggered environmental changes in central Italy for the past c. 28 cal ka. The Lake Albano record further demonstrate that at least the earliest changes reflect distinct warm/cold cycles that triggered major lake level changes of millennial to centennial duration as a major response of the lacustrine basin to climate forcing. Alternatively, these dramatic lake level variations also identified during the Holocene could have been driven by CO2 injec tions of possible magmatic origin. However, flickering interannual to interdecadal variations further identified within these cycles can be correlated to oscillations of the North Atlantic NAO as observed in Greenland ice cores, marine and other lacustrine records. The latter, thus, would favour the climatic rather than volcanic cause for these changes. The Holocene record in both lakes is characterized by organic rich sediments with a variable development of lamination. Although human activity in the catchment is evident since the mid Holocene, the global signal indicates that changes in climatic variables such as wind intensity, precipitation and temperature are the most probable factors producing these environmental changes. The response of both lake systems to probable warm/cold episodes during the late Holocene, however, is difficult to disen tangle from the often contemporaneous human impact on their catchments. The Colli Albani Volcano Funiciello R. Giordano G. 978 1 86239 307 3 Vigliotti, L., D. Ariztegui, A. Lami P. Guilizzoni. 2010. Reconstructing natural and human induced environmental change in central Italy since the late Pleistocene The multi proxy records from maar lakes Albano and Nemi. In Funiciello, R. G. Giordano eds. . 2010. The Colli Albano Volcano. IAVCEL special publication, Geological Society, London 245 257. Reconstructing natural and human induced environmental change in central Italy since the late Pleistocene The multi proxy records from maar lakes Albano and Nemi. Vigliotti_et_al_Paper_Albano_Nemi_GSL.pdf Contributo in volume Geological Society. 1750 8207 Special publications of the International Association of Volcanology and Chemistry of the Earth s Interior Special publications of the International Association of Volcanology and Chemistry of the Earth s Interior Spec. pub. Int. Assoc. Volcanol. Chem. Earth Inter. Special publications of the International Association of Volcanology and Chemistry of the Earth s Interior. Special publications of IAVCEI piero.guilizzoni GUILIZZONI PIERO andrea.lami LAMI ANDREA TA.P02.005.002 Uso della paleolimnologia come strumento per lo studio del paleoclima e dell evoluzione climatica |
