This paper presents an event stratigraphy based on data documenting lake-level changes as well as volcanic eruptions over the period 4500–3500 cal. BP from sediment sequences of Lakes Accesa in Tuscany (north-central Italy) and Maliq (Albania) in the central Mediterranean. The available data make it possible to recognise a tripartite climatic oscillation between c. 4300–3800 cal. BP. A phase characterised by drier conditions at c. 4100–3950 cal. BP appears to have been bracketed by two phases marked by wetter conditions and dated to c. 4300–4100 and 3950–3850 cal. BP, respectively. The deposition of theAvellino tephra occurred during the first humid phase, slightly before 4300 cal. BP, and that of an interplinian tephra AP2-AP4 (or Pr1) around 4050 cal. BP during the dry intermediate phase. This dry median episode may be related to the so-called ‘4.2 ka event’ observed in tropical areas as well as in northwestern Italy. A comparison of the Accesa lake-level record with palaeoclimatic terrestrial and marine records suggests that this complex climatic oscillation around 4300–3800 cal. BP affected the central and western Mediterranean area. The key position of the 4300–3800 cal. BP climatic oscillation at a crucial transition from mid to late Holocene in the Mediterranean and tropical areas, deserves major consideration in further investigations.
Possible complexity of the climatic event around 4300-3800 cal. BP in the central and western Mediterranean.
ZANCHETTA, GIOVANNI;
2009-01-01
Abstract
This paper presents an event stratigraphy based on data documenting lake-level changes as well as volcanic eruptions over the period 4500–3500 cal. BP from sediment sequences of Lakes Accesa in Tuscany (north-central Italy) and Maliq (Albania) in the central Mediterranean. The available data make it possible to recognise a tripartite climatic oscillation between c. 4300–3800 cal. BP. A phase characterised by drier conditions at c. 4100–3950 cal. BP appears to have been bracketed by two phases marked by wetter conditions and dated to c. 4300–4100 and 3950–3850 cal. BP, respectively. The deposition of theAvellino tephra occurred during the first humid phase, slightly before 4300 cal. BP, and that of an interplinian tephra AP2-AP4 (or Pr1) around 4050 cal. BP during the dry intermediate phase. This dry median episode may be related to the so-called ‘4.2 ka event’ observed in tropical areas as well as in northwestern Italy. A comparison of the Accesa lake-level record with palaeoclimatic terrestrial and marine records suggests that this complex climatic oscillation around 4300–3800 cal. BP affected the central and western Mediterranean area. The key position of the 4300–3800 cal. BP climatic oscillation at a crucial transition from mid to late Holocene in the Mediterranean and tropical areas, deserves major consideration in further investigations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
