Glacier Melting Triggers Massive Gravel Deposition in Central Italy's River Basins, Unveiling Deglacial Events From 1250 to 780 ka.

The purpose of this study was to prove the direct correlation of a successions of gravel‐clay beds recovered in borehole with the melt‐water pulses associated with the sea‐level oscillations indicated in the δ18O record in the time‐span preceding the 100‐kyr glacial cycles. Aimed at this scope, we provide combined 40Ar/39Ar and paleomagnetic constraints to a set of seven aggradational successions recovered from a 120 m deep borehole drilled in the buried Paleo‐Tiber delta in Rome (central Italy). The geochronologic constraints enable the correlation of each aggradational succession, characterized by a sudden transition from coarse gravel at the base to sandy clay sediments, with periods of sea‐level rise indicated by the δ18O curve encompassing MIS 37 through MIS 19, from 1250 to 780 ka. This stratigraphy, provides a unique and unprecedented well‐dated evidence of glacial/deglacial events, matching the global benthic δ18O stack during this time frame. Furthermore, this study validates the hypothesis that gravel deposition in the catchment basin and the delta of the main rivers in central Italy is triggered by the melting of glaciers in the Apennines Mountain range. It demonstrates the significant potential of these deglaciation proxies to be used worldwide to unravel the chronology of glacio‐eustatic events. Plain Language Summary: In this study, we used a combination of dating techniques and paleomagnetic data to examine a series of sediment layers found in a buried ancient river delta in Rome, Italy. These sediment layers were collected from a 120 m deep borehole. By analyzing the age of these sediment layers, we were able to link them to a period in the past when sea level was rising. This sea‐level rise occurred between 1250 and 780 ka, covering a range of time from MIS 37 to MIS 19. These sediment layers show a distinct change from coarse gravel to sandy clay, which provides valuable information about glacial and deglacial events. These findings support the idea that the deposition of gravel in river catchment areas and deltas in central Italy is linked to the melting of glaciers in the Apennines Mountain range. This research not only validates this hypothesis but also highlights the potential for using similar techniques globally to better understand the timing of glacio‐eustatic events. Key Points: We provide 40Ar/39Ar and paleomagnetic constraints to seven aggradational successions recovered from a 120 m deep borehole in RomeEach aggradational succession is correlated with a period of sea‐level rise encompassing MIS 37 through MIS 19, 1250 to 780 kaThis study shows that gravel deposition in the catchment basin of the main rivers in central Italy is a direct proxy of deglacial events [ABSTRACT FROM AUTHOR]