Studia Quaternaria

Although much has been written about a cosmic impact event in the Western Alps of the Mt. Viso area, the event closely tied with the Younger Dryas Boundary (YDB) of 12.8 ka and onset of the Younger Dryas (YD), the affected land surface is considered to contain a similar black mat suite of sediment found on three continents. While work elsewhere has focused on recovered sediment from lake and ice cores, buried lacustrine/alluvial records, and surface glacial and paraglacial records, no one has traced a mountain morphosequence of deposits with the objective of investigating initial weathering/ soil morphogenesis that occurred in ice recessional deposits up to the YDB when the surface was subjected to intense heat, presumably, as hypothesized by Mahaney et al. (2016a) from a cosmic airburst. With the land surface rapidly free of ice following glacial retreat during the Břlling-Allerřd interstadial, weathering processes ~13.5 to 12.8 ka led to weathering and soil morphogenesis in a slow progression as the land surface became free of ice. To determine the exposed land character in the mid- to late-Allerřd, it is possible to utilize an inverted stratigraphic soil morphogenesis working backward in time, from known post-Little Ice Age (LIA) (i.e. time-zero) through LIA (~0.45 to ~0.10 ka), to at least the middle Neoglacial (~2 ka), to answer several questions. What were the likely soil profile states in existence at the end of the Allerřd just prior to the cosmic impact/airburst (YDB)? Assuming these immature weathered regolith sections of the Late Allerřd approximated the <1 ka old profiles seen today, and assuming the land surface was subjected to a hypothesized instant temperature burst from ambient to ~2200oC at ~12.8 ka, what would be the expected effect on the resident sediment? To test the mid-LG (YDB) to YD relationship we analyzed the paleosols in both suites of deposits – mid-LG to YD – to test that the airburst grains are restricted to Late Allerřd paleosols and using relative-age-determination criteria, that the overlapping YD to mid-LG moraines are closely related in time. These are some of the questions about the black mat that we seek to answer with reference to sites in the upper Guil and Po rivers of the Mt. Viso area.

The site at Orłowo Cliff was used to analyse the stratigraphic position and palaeogeographic interpretations of the properties and depositional conditions of two basal tills from the Late Pleistocene. A multi-proxy approach involved lithofacies, petrographic analysis of the fine gravel fraction, analyses of indicator erratics and till fabric. TL dating of intra-moraine deposits was used to determine depositional time frames of tills. The sediment profile at Orłowo Cliff shows a distinct reduction in number of Pleistocene units. Obtained dating results suggest the presence of Middle and Late Pleistocene fluvial units. The main issue discussed is the stratigraphic position of the older till (Unit O-4). It can be assumed that this till was deposited probably during the Middle Weichselian (MIS4). At Orłowo Horn the till of Unit O-4 reveals incorporation of the erratic material derived from an older till in the surrounded area (according to petrographic composition – probably from MIS 8). The younger till (Unit O-6) was deposited in the Late Weichselian (MIS 2). Moreover, the till of Unit O-6 is characterised by a significant shift towards the south-west in terms of the erratic origin in Unit O-4.

Palynological and archaeobotanical analyses were conducted on excavated sediments from Tse Dura, a Later Stone Age rock shelter in north-central Nigeria with the aim of reconstructing the environment conditions at the site within the last millennium. From 933 ± 29 BP to 802 ± 29 BP, the environment alternated between Guinea savanna with dry conditions, and secondary and riverine forests with humid conditions. During these periods of environmental fluctuations, the LSA populations engaged in the management of economic plants the most significant of which included Dioscorea spp. Pennisetum glaucum and Elaeis guineensis, and exploited wild plants such as Pavetta crassipes, Sarcocephalus latifolius and Lophira cf. lanceolata for dietary and ethnomedicinal purposes. Around 310 ± 30 BP cal, the environment became very wet after which it was succeeded by a drier period. It was during this period that Sorghum bicolor became prominent, and the environment attained its current status dominated by Guinea savanna elements and secondary forests.

Archaeology of north-eastern Poland has been poorly recognized owing to vast forest areas and numerous lakes. This particularly refers to the Warmian–Masurian Voivodship, where forest covers over 30% of its area. Prospection of forested areas has become possible in Poland just over 10 years ago with the Airborne Laser Scanning (ALS) and Light Detection and Ranging (LiDAR). These techniques allow obtaining 3-D documentation of recognized and also unknown archaeological sites in the forested areas. Thanks to ALS/LiDAR prospection a significant number of archaeological structures have been identified also in the Warmia and Masuria regions. Among them oval-shaped hillforts, surrounded by perfectly spaced concentric moats and ramparts, located mainly on islands and in wetland areas, have raised particular attention. Based on field prospection and results of preliminary excavations, these objects have been considered as Iron Age hillforts. One of the best preserved objects of this type is on the Radomno Lake island, located several kilometres to the south of Iława town. Integrated geoarchaeological prospection of this hillfort emphasized benefits of using LiDAR in combination with results of geophysical prospection and shallow drillings. Applied methodology enabled to document the hillfort shape, and to study its geological structure and stratigraphy. The results clearly indicate that integration of LiDAR data with geophysical prospecting is indispensable in future archaeological surveys. It is a perfect tool for remote sensing of archaeological objects in forest areas, so far not available for traditional archaeology.