ICDP Fucino paleolake project: the longest continuous terrestrial archive in the MEditerranean recording the last five Million years of Earth system history (MEME)

  During the last 5 Ma (Pliocene-Holocene) the Earth’s climate system has undergone a series of marked changes, including; (i) the shift from the warm state Pliocene to the cold state Pleistocene, (ii) the evolution in frequency, magnitude and shape of glacial-interglacial cycles at the Early Middle Pleistocene Transition (~1.25-0.65 Ma), and (iii) the appearance of millennial-scale climate variability. While much of this paleoclimatic narrative has been reconstructed from marine proxy records, relatively little is known about the expressions of these major changes in continental areas and their impact on terrestrial environments and biodiversity, thus resulting in a significant knowledge gap surrounding a fundamental component of the Earth’s climate system. In the framework of the Mediterranean area, a region that is sensitive to changes in temperature and hydrological cycle, the Fucino Basin in Central Italy stands out as one of the few sites that meets the necessary requirements to fill this gap. The geophysical evidence and the stratigraphical, geochronological and multi-proxy data for multiple sediment cores acquired in recent years, indicate that the Fucino lacustrine succession (i) spans continuously for at least 4.6 Ma, (ii) is highly sensitive to climate change, and (iii) contains an outstanding number of volcanic ash layers, which facilitate an independent, high-resolution time-scale. With respect to the half-graben, wedge-shape geometry of the basin, three drilling targets were identified: MEME-1, located in the middle of the basin, would intersect the whole Quaternary infill and the upper part of the Pliocene continental sequence at ~400-500 m depth; MEME-2, which is located ca. 1.8 km west of MEME-1, where the sedimentation rate is lower, and is ~400-500 m deep, allows recovery of the entire Pliocene-Quaternary infill reaching the Messinian substratum; MEME-3 (~250-300 m depth), located for tectonics objectives on the footwall of the basin master fault and covering, though discontinuously, the lake history back to ~4.6 Ma. Through a multi-method dating approach, and a multi-proxy analysis of sedimentary physical and biogeochemical properties, the MEME project will provide a detailed record of changes in the Earth climate system and the environmental-ecological response, independent of any a priori assumptions on response times to climate forcing and feedback mechanisms. Furthermore, the Fucino sedimentary succession has enormous potential to reconstruct a uniquely comprehensive long-term, high-temporal resolution record of peri-Tyrrhenian explosive volcanism and of the post-orogenic extensional tectonics in this area of the Apennine chain.