A large number of Sus remains were recently collected from early Holocene sediments of Tsudupisuki-abu Cave on Miyako Island of the Southern Ryukyus, Japan, during excavations. Wild boar (Sus) are ...now absent from the island, where Sus remains were also uncommon in Quaternary fossil localities before the excavations. Taxonomic analyses of the Sus remains, especially metrical analysis of third molars, have revealed that the remains are divided into two clusters (A and B) of different size. Cluster A consists of larger specimens and cluster B of smaller specimens and are referred, respectively, to Sus scrofa and Sus sp. On the basis of the information of Sus remains from this cave and another locality (Pinza-abu Cave), we reconstruct a late Quaternary history of Sus on Miyako Island. It is inferred that large-sized Sus scrofa was introduced by humans onto the island in the late Late Pleistocene, and then reduced in size to be Sus scrofa of Tsudupisuki-abu Cave by a mechanism of insular dwarfism until the early Holocene. On the other hand, the second human introduction of a miniature Sus form (= Sus sp.) seems to have taken place in the earliest Holocene.
El Olivo Cave (Pruvia de Arriba, Llanera, Asturias, Spain) is a small karst cave located in the Aboño River basin and formed in the Cretaceous limestone of the Mesozoic cover of the Cantabrian ...Mountains (north of the Iberian Peninsula). It contains an important upper Pleistocene sedimentary, archaeological, and paleontological record, with abundant technological evidence and faunal remains. The archaeological record shows a first occupation that could correspond to the Middle Paleolithic and a second occupation in the Middle Magdalenian. The stratigraphic sequence inside and outside the cave was studied with geoarchaeological methodology. In this paper, the lithostratigraphic sequence is analyzed, and the data from the granulometric, mineralogical, edaphological, and radiometric analyses are presented. The results of these analyses enable an accurate interpretation of both the lithostratigraphy of the deposit and the processes responsible for its formation and subsequent evolution. The available numerical dates allow us to locate the first sedimentation episode in the cave in OIS 7a, in the Middle Pleistocene, the base of the outer fluvial sedimentation in the cold OIS 3a stage of the Upper Pleistocene and the Magdalenian occupation in the Last Glacial Maximum (OIS 2) at the end of the Late Pleistocene.
Central Asian caves with Palaeolithic deposits are few, but they provide a rich record of human fossils and cultural assemblages that has been used to model Late Pleistocene hominin dispersals. ...However, previous research has not yet systematically evaluated the formation processes that influence the frequency of Palaeolithic cave sites in the region. To address this deficiency, we combined field survey and micromorphological analyses in the piedmont zone of south Kazakhstan. Here, we present our preliminary results focusing on selected sites of the Qaratau mountains. Sediment cover varies among the surveyed caves, and loess‐like sediments dominate the cave sequences. The preservation of cave deposits is influenced by reworking of cave sediments within the caves but also by the broader erosional processes that shape semiarid landscapes. Ultimately, deposits of potentially Pleistocene age are scarce. Our study provides new data in the geoarchaeologically neglected region of Central Asia and demonstrates that micromorphology has great analytical potential even within the limitations of rigorous survey projects. We outline some of the processes that influence the formation and preservation of cave deposits in Kazakhstan, as well as broader implications for the distribution of Palaeolithic cave sites in Central Asia and other semiarid environments.
This study characterizes and provides ages for an extensive sedimentary record occurring in Lapa Doce and Torrinha caves, NE Brazil. With >40km of surveyed passages, these caves integrate a ...distributary cave system fed by allogenic recharge from the surrounding sandstone plateaus. Sediment petrography together with descriptions of depositional facies and architectural elements shows four depositional units related to fluvial and standing water environments. These include, from bottom to top: (1) a channel unit including lateral bars deposited during an ordinary flood regime; (2) a sandy flood unit including minor channel and scour fills derived from bank-full equivalent flood events; (3) mud caps deposited in standing water that often reach the ceiling; and (4) intraclast breccias associated with collapse of the mud caps under saturated conditions. The deposits were dated using a combination of cosmogenic nuclide burial dating and U-series dating of flowstone. Cosmogenic nuclide data point to fluvial aggradation being active since 1.91+0.12My and extending until 0.36±0.08My, with intensive cave and valley aggradation events between 0.78±0.10My and 0.44±0.12My. Long term alluviation of the cave system seems to be important in forming passages, determining their configuration, and setting up a general distributary pattern evident in passage morphology and sedimentary sequences. Mud caps overlapping the fluvial deposits are interpreted as the products of successive rising and lowering of the water table (static level). Radiometric ages of interstratified flowstones and speleothems show that these oscillations were active at least since 115ky ago and finally ceased around 12ky ago, indicated by the recurrent age obtained from uneroded capping flowstones. These long-term water table oscillations may drive paragenetic expansion of the whole cave system. Valleys, caves and other landforms in our study area are part of an ancient landscape with multiple episodes of burial and exhumation. Despite the possibility of much older sediment being preserved somewhere in the cave system, our data indicate a younger Quaternary age for the bulk of the sediment filling the study caves.
•A depositional model for the sedimentary infill found in the caves is proposed.•Caves and surface stream aggradation active since 1.9My with an average denudation rate of 2m/My•Fluvial aggradation intensified between 0.78±0.10My and 0.44±0.12My.•Caves are part of an ancient landscape with episodes of burial and exhumation.•Sedimentary data enhance discussions about speleogenesis: timescales and processes ordering.
Clastic sediments deposited at the bottom of the vertical, nearly 1000 m deep Njemica Cave (Biokovo Mountain, Croatia) were analysed. Owing to the vertical morphology of the cave, the occurrences of ...clastic sediments are sparse. Small, up to decimetre-thick, undisturbed sediment accumulations situated near the siphon lake revealed interesting palaeontological and mineralogical data. These data are used as a useful proxy for discussing depositional processes, the provenance of the sediments and paleo-habitats of the subterranean fauna.
The sub-recent assemblages of ostracods were discovered within the sediment, and they were shown to be correlative to the known endemic species in the wider Dinaric Karst area (Pseudocypridopsis sywulai and Phreatocandona cf. motasi). The well-preserved sediment archive indicates the allogenic origin of the sediment and defines it as an allochthonous infiltrate of the Quaternary. The detritus originates from Pleistocene–Holocene deposits in the surrounding area, whose composition was influenced by volcanic activity in the wide Adriatic region. Sedimentation occurred in a calm aquatic environment by settling from suspension. Therefore the sediments are defined as slackwater deposits.
Modern and fossil pollen grains extracted from bat guano in Arnhem Cave are evaluated for their potential as a palynological archive and the possible influence of insectivorous bat behaviour on the ...pollen contents of their dung. Four out of seven fossil guano samples from this cave were productive. The inconsistent preservation of pollen in bat guano layers may be due to deterioration through various mechanisms, including combustion. The samples that did contain pollen support previous conclusions, derived from pollen in spring deposits, about Holocene palaeoenvironmental changes in central Namibia. Two samples of modern bat dung yielded pollen spectra with a greater proportion of woody plant pollen than grass pollen in comparison with the fossil guano material, indicating denser tree cover than in the past, which may be due to the possible effect of modern farming practices. Differences in the pollen composition in dung of different bat species foraging in a relatively homogenous African savanna suggest that the behaviour of likely bat populations should be accounted for when using bat guano as a palynology source for environmental reconstruction.
This study examines the relationship between the flooding of cenotes and formation of coastal mangrove with Holocene sea-level rise and the onset of aquatic sedimentation in Yax Chen, a cave system ...in Quintana Roo on Mexico's Yucatan Peninsula. Sediment depth measurements (n=180) were collected along 2.7km of an underwater cave passage and three cores were radiocarbon dated to examine both the extent and timing of sedimentation in the cave. Basal radiocarbon ages (~4Ka) for aquatic sediments in the cave show that Holocene sea-level rise flooded cenotes, creating sunlit open water conditions with associated mangroves on the upper karst surface. These conditions initiated abundant and widespread sedimentation in the cave. Cenote surface area controlled the long-term sediment accumulation in the cave passages through primary productivity in the sunlit open water areas of the cenotes. This primary productivity was enhanced with mangrove formation, which causes funneling of precipitation and nutrient-rich waters into the cenotes from the mangroves. Accumulation histories from the radiocarbon-dated sediment cores (n=3) were compared with accumulation histories in previously published studies including Actun Ha, Mexico and Green Bay Cave (GBC), Bermuda.
•We examine the relationship between Holocene sea-level rise and aquatic sedimentation.•It is shown that Holocene sea-level rise flooding cenotes affected sedimentation in the caves.•Topography and sea-level rise affected the distribution and amount of sedimentation in the caves.•Abundant OM sedimentation in Yax Chen began at~3500calyr BP.•We demonstrate that anchialine caves are subject to rapid shifts in sedimentation.
Karstic cave systems are intricately related to surficial processes and the study of cave sediments is a growing field of research. Sediment deposits in caves are protected from surficial weathering ...processes, and are therefore often preserved. Hidden River Cave is an active, multi-level cave system in the town of Horse Cave, Kentucky with over 33 km of mapped passages. A history of anthropogenic impacts on the cave system include uses for hydroelectric power generation, a water source, and a show cave until it closed in 1943 due to severe contamination from domestic and industrial waste. Analysis of sediment cores from the cave system show distinct concentrations of metals within the sediment from chrome plating plant effluent. Relative concentrations of metals in the core record were obtained using an Itrax core scanner, and were observed to decrease moving downstream from the chrome plating plant contamination source. The chronology of sedimentation events indicates a strong connection between historical contaminating events in the town of Horse Cave and cave sediment deposition. This approach emphasizes how core analysis allows for depositional patterns in the cave system to be determined and related to historic surficial processes. The methodologies emphasis the potential for the analysis of sediment trapped within cave systems may be used to shed insight into a regions anthropogenic and natural events.
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