Palaeoenvironmental and climatic inferences from the late early Pleistocene lacustrine deposits in the eastern Tiberino Basin (central Italy)

Abstract

Within the Neogene-Quaternary evolution of the Mediterranean intermountain basins, the eastern Tiberino Basin provides new multifaceted chronological, biostratigraphic, palaeoecological, and palaeoenvironmental information, appreciably improving the knowledge of palaeoenvironmental and climate conditions during the middle-late Matuyama Chron (late early Pleistocene). Shallow to relatively deep lacustrine deposits and alluvial plain deposits, magnetostratigraphically calibrated, hold malacofaunas, ostracofaunas, and carpological remains, as well as a pollen record. Palaeocarpological remains widely originated from the local (azonal) vegetation of waterlogged environments. Nonetheless, some taxa show transitional morphology between possibly extinct Pliocene-Pleistocene forms and living taxa. The pollen record highlights a conifer-dominated forest phase, indicating a temperate-wet interglacial period, well aligned inside the schemes for the same latitudinal band. The abundance of tree taxa currently absent from the Italian peninsula points to pre-Jaramillo late early Pleistocene biostratigraphical characters, here compared to other sections from central Italy, and contributes to a better definition of modes and timing of their disappearance in southern Europe. Malacofaunas and ostracods, still with late early Pleistocene features, together with Charophyte, mark repeated fluctuations in energy, temperature, and chemical composition of water. The overall record identifies an incipient diachronous cooling trend, for the first time recognized in southern Europe.

Integrated Stratigraphy of the Marine Early Pleistocene in Umbria

“…In fact, the consequences of climatic change in southern Europe betweenthe late Pliocene and early Pleistocene are only partly comparable with the main situation of the northern hemisphere [7,21], and a latitudinal effect has been noted [95]. Still, during the lower early Pleistocene, central Italy was a refuge for several floral and faunal taxa that were able to tolerate a relative cooling in air and water temperatures [21].…”

“…Still, during the lower early Pleistocene, central Italy was a refuge for several floral and faunal taxa that were able to tolerate a relative cooling in air and water temperatures [21]. Even approximating the early-middle Pleistocene boundary, the deterioration of the climate mainly shifts toward dry/arid rather than cold conditions [7,95]. Consequently, still inside a general coolingtrend, the main effects on marine water temperature depend on the bathymetry, deep water being cool (but never really cold), while shallow water still allowing the life cycle of relatively warm benthic taxa [19][20][21].…”

Evidence of Predation on Early Pleistocene Freshwater Ostracods (Umbria, Central Italy)

“…The female right valves (45) are numerically more common, while the male right valves (2) are subordinate (Table 1). Apparently, the data indicate that the right valves are the choice of predators, but this phenomenon is at present unclear.…”

“…A situation of this type could be indicative of a time-lag between the reproductive cycles of prey and predators [44]. The female right valves (45) are numerically more common, while the male right valves (2) are subordinate (Table 1). Apparently, the data indicate that the right valves are the choice of predators, but this phenomenon is at present unclear.…”

Early Pleistocene environments before, during and after the first expansion of early Homo into Southern Spain

“…The continental pollen profile from Arquata quarry, near Bevagna (Bizzarri et al, 2018) describes a transition from humid to dry phase around 1.4/1.7 Ma. Similar to other profiles from Central Italy, the high proportion of trees (especially rich in Cedrus and Carya) makes these assemblages radically different from the ones in Palominas.…”