Micromorphological insights within the Middle Pleistocene-Holocene cave sediment record of Grotta Romanelli, Italy.

Grotta Romanelli (Apulia, southern Italy) is a key-site in Mediterranean archaeology. In the long history of excavations since the early 20^th century, its sedimentary archive has revealed important information about human frequentation, vertebrate faunas, and environmental changes, inside a time frame which includes the Middle Pleistocene (ca. 350 ka BP) and the Early Holocene (ca 11 ka BP). The peculiarity of the sedimentary succession, which consists of fine- to very fine-grained sediments with weakly-developed or massive sedimentary structures, determined a thorough micromorphological investigation. Indeed, these sedimentary structures are often associated with human-settled cave environments. Thus, the micromorphological analysis is of utmost importance for determining the sedimentary and geomorphological context of an archaeological site. In this respect, we present for the first time the results at a more detailed scale of the depositional environments of Grotta Romanelli, in order to understand the role of sedimentary, post-depositional and anthropogenic processes in the formation of the stratigraphy of the cave.

The micromorphological investigation highlights several microfacies associated with the finer-grained sediments. The sediments within the deposit is mainly allochthonous as evidenced by the abundance of aeolian quartz and remnants of leached soils, thus indicating erosion and transport into the cave. Moreover, the characterisation of the microfacies suggests runoff and standing water processes as main agents of the internal redistribution of material. This also includes, albeit to a lesser extent, phases of biological activity, as well as phases of relative surface stability and anthropogenic contributions. Anthropogenic inputs are mainly related to fire activity and food exploitation, such as charcoal, charred plant tissue, and burnt bones. Notwithstanding the extensive volume of sediments excavated during historical archaeological campaigns, especially in the mid-frontal sectors, results show that anthropogenic inputs are not restricted to specific areas within the cave, due to its dimensions, rather they are sporadically scattered across the microfacies.