The MIS 13 interglacial at Ceprano, Italy, in the context of Middle Pleistocene vegetation changes in southern Europe

Abstract

Climatic and environmental changes of the Middle Pleistocene in Europe provide the context for an important phase in the evolution and dispersal of early hominins. Pollen records from terrestrial and marine sediment sequences reveal patterns not usually visible in palaeoenvironmental reconstructions from archaeological sites alone and show that hominin evolution took place against a background of marked environmental change as forests expanded and contracted in concert with global and regional climatic shifts. It is rare to find archaeological material in stratigraphically long and continuous palaeoenvironmental sequences, yet this is what is needed to enable particular phases of hominin evolution to be securely associated with climatic and environmental changes. At the well-known Middle Pleistocene archaeological site of Ceprano in Italy we have been able to produce a pollen record from the sedimentary unit directly below the stratum of the hominin remains. The new pollen data from Ceprano are presented here in full for the first time and provide a detailed picture of interglacial vegetation development during Marine Isotope Stage (MIS) 13. This evidence contributes significantly to our knowledge of the spatial heterogeneity of ecosystem responses to climatic change during this period and helps to further constrain the age of the hominin remains. New sites combining both archaeology and long, continuous high quality palaeoecological records would help clarify the relationship between hominin presence and palaeoclimatic and palaeoenvironmental conditions. In the meantime, better communication between the research communities can also go a long way to improving our understanding of the links between the two.

Stratigraphy, sedimentology, and archaeology of Middle Pleistocene localities near Ceprano, Campogrande area, Italy

“…The new and detailed stratigraphic and sedimentological data collected at Campogrande have provided further information on the history of the Lirino Lake, where the Ceprano calvarium was found. Our analysis of the stratigraphy of this area (c.f., Manzi et al, 2010; Margari et al, 2018) reinforces the conclusion that the hominin specimen was deposited in fluvial floodplain, constituting the final filling of the Lirino Lake.…”

“…Conversely, there is no evidence of erosion at CG1, while we observe the conditions for the formation of accommodation space that was utilized by the lacustrine systems to aggrade and prograde, filling the basin. Coherent with these observations, data from the palynological analysis of samples from core C1 (Margari et al, 2018) suggest two different forest periods, separated by an interval of herb-dominated vegetation, which are both assigned to MIS 13 (interglacial phase). The erosional surface separating the unit C from unit D in the same core is attributed to MIS 12 (glacial phase), pointing out that the timing of deposition of the human calvarium in unit D is within MIS 11, as already hypothesized by Manzi and colleagues (2010).…”

“…In the lower and upper portion of this unit, pollen assemblages suggest the continuous presence of a closed-canopy forest that requires temperate climatic conditions associated with interglacial periods. By contrast, the middle portion indicates an interval of increased aridity and lower temperatures that should correspond to a glacial period (Margari et al, 2018). Another discontinuity surface, detected at 14.7 m below the top of the core, separates the unit C from unit D. The sediments of unit D are those in which the calvarium was discovered and are sterile from a palynological point of view (Margari et al, 2018); they indicate a muddy-sand deposition in palustrine-lacustrine shallow water, upward replaced by fluvial deposits whose sedimentological characters are visible in the trench T of locality CG9.…”

“…As for the age of the Ceprano calvarium, it has been suggested a chronology bracketed between 430 and 385 ka (MIS 11; Manzi et al, 2010), in contrast to the original hypothesis of about 800–900 ka (Ascenzi et al, 1996, 2000). The chronology of the calvarium pointed out by Manzi and colleagues (2010) was obtained through a multidisciplinary approach, which included stratigraphic-sedimentological analysis, palynological data, geochemistry, soil-micromorphology, taphonomy, and the archaeological evidence (see also Di Vincenzo et al, 2017; Margari et al, 2018). The date bracketed between 430 and 385 ka is also consistent with the normal geomagnetic polarity recorded in the area (Muttoni et al, 2009) and with the age of 353 ± 4 ka (±1σ full external errors), obtained by Nomade and colleagues (2011; see also Pereira et al, 2018) by sampling the coarse-grained volcanoclastic layer above the clay containing the human specimen.…”

“…In this paper, combining new data with a reappraisal of previous studies in the area (Muttoni et al, 2009; Manzi et al, 2010; Nomade et al, 2011; Margari et al, 2018; Pereira et al, 2018), we provide a comprehensive stratigraphy and sedimentology of the uppermost fluvio-palustrine deposits of Campogrande, including those where the human calvarium was discovered. In addition, we describe for the first time the archaeological lithic material found in the overlying fluvial deposits of the localities labelled CG9 and CG10, furnishing further constrains to ascribe the human presence at Campogrande to a period spanning around MIS 11.…”