Middle to late Holocene environmental evolution of the Pisa coastal plain (Tuscany, Italy) and early human settlements

Abstract

A cross-disciplinary (sedimentological, geochemical, micropalaeontological and archaeological) examination of 12 continuous cores, up to 20m long, integrated with stratigraphical, geomorphological and historical investigations, allows for reliable delineation of the middle-late Holocene environmental evolution in the Pisa old town area, with special emphasis on the Etruscan age transition. Depositional facies were identified through integration of sedimentological and micropalaeontological (benthic foraminifers, ostracods, phytoclasts and palynomorphs) data, while sediment dispersal patterns were reconstructed on the basis of geochemical analyses. Facies architecture was chronologically constrained by combined archaeological and radiocarbon dating. The turnaround from early Holocene, transgressive conditions to the ensuing (middle-late Holocene) phase of sea-level highstand is witnessed by a prominent shallowing-upward succession of lagoonal, paludal and then poorly drained floodplain deposits supplied by two river systems (Arno and Serchio). This 'regressive' trend, reflecting coastal progradation under nearly stable sea-level conditions, was interrupted by widespread swamp development close to the Iron-Etruscan age transition. The expansion of vast, low-lying paludal areas across the alluvial plain was mostly induced by the intricate, short-term evolution of the meandering Arno and Serchio river systems. These changes in the fluvial network, which occurred during a period of variable climate conditions, strongly influenced the early Etruscan culture (7th-5th century BC) in terms of human settlement and society behaviour. Conversely, a strong impact of human frequentation on depositional environments is observed at the transition to the Roman age (from the 1st century BC onwards), when the wetlands were drained and the modern alluvial plain started to form. The palaeoenvironmental reconstruction fits in with the original geographical descriptions mentioned in Strabo's Chronicles, and provides chronologically constrained data of fluvial evolution from the Pisa old town area. © 2013 Elsevier Ltd and INQUA

Climatic signature of two mid–late Holocene fluvial incisions formed under sea-level highstand conditions (Pisa coastal plain, NW Tuscany, Italy)

“…Following the characteristic mid-late Holocene progradation trend, shared by all major Mediterranean delta systems (Somoza et al, 1998;Bellotti et al, 2004;Aguzzi et al, 2005;Vella et al, 2005;Amorosi et al, 2008Amorosi et al, , 2013bMilli et al, 2013), the marshlands emerged and abruptly turned into floodplain areas at the transition with the Bronze age, around 3800 cal yr BP (Fig. 3A-D).…”

“…The stratigraphic architecture of the Pisa Plain prograding sedimentary wedge was investigated by means of a dense grid of cross-sections, following the paths of the highest quality core data stored into the georeferenced subsurface dataset (Amorosi et al, 2013b) with maximum spacing of~500 m (Fig. 2).…”

“…2. Location map of the study area reporting the georeferenced subsurface dataset used for this work (from Amorosi et al, 2013b). The reference MAPPA cores are shown by white stars.…”

Seawater intrusion via surface water vs. deep shoreline salt-wedge: A case history from the Pisa coastal plain (Italy)

“…The subsequent evolution of the Pisa area saw the development of a wide, thick, clay-dominated, lagoonal succession, controlled by the inherited paleotopography (Rossi et al, 2011). At the time of maximum marine ingression (7.8 cal ka BP, (Amorosi et al, 2013)), the shoreline was located more than 7 km inland from its present position.…”

Climate change and social vicissitudes in China over the past two millennia

“…Climate change has long been suggested to be an important factor in facilitating sustainable human development (Issar and Zohar, 2007;Ge et al, 2013a). During recent decades, many research studies have been conducted worldwide regarding the impacts of historical climate change; for example, the impact of climate change on agricultural production, human population and migration, disease and human health, human settlements, human activities, social unrest, the rise and fall of ancient civilizations, and transmission of climate change impacts (Weiss and Bradley, 2001;Haug et al, 2003;Zhang et al, , 2011Fan, 2010;Lee and Zhang, 2010;Büntgen et al, 2011;Amorosi et al, 2013;Hsiang et al, 2013;Welc and Marks, 2014;Chull et al, 2014;Su et al, 2014;Zheng et al, 2014;Wei et al, 2014Wei et al, , 2015Yin et al, 2015;Fang et al, 2015;Xiao et al, 2015). The results include the drought-induced collapse of the Akkadian civilization in western Asia and the Mayan civilization (deMenocal, 2001;Haug et al, 2003) and the strong coincidence between climate change and major events in the history of central Europe over the past 2500 yr (Büntgen et al, 2011).…”