Quaternary Science Advances最新文献

{"title":"Evaluation of watertightness and slope stability analysis of Upper Guder dam, West Showa, Central Ethiopia","authors":"Belay Birhanu ,&nbsp;Yadeta C. Chemeda ,&nbsp;Tola Garo ,&nbsp;Shankar Karuppannan","doi":"10.1016/j.qsa.2024.100230","DOIUrl":"10.1016/j.qsa.2024.100230","url":null,"abstract":"<div><p>Ethiopia is currently emphasizing the construction of micro dams to enhance agricultural productivity and assure food security. The Upper Guder Dam, situated in the West Shoa Zone, Central Ethiopia, is one such project. However, the dam faces challenges due to complex geological and structural conditions, including leakage and slope instability. Hence, this study focuses on addressing the abutment slope stability and watertightness condition of this dam. Accordingly, the study employed discontinuity surveying, Seismic Refraction Tomography (SRT), Rock Quality Designation (RQD), and Lugeon testing to assess the water tightness. Additionally, kinematic analysis and the Limit Equilibrium Method (LEM) were used to evaluate abutment slope stability. Results from surface geological mapping and core drilling showed that the dam site is constituted by quaternary soil, tuff, and basalt. The Lugeon test results indicate that the left abutment of the dam is susceptible to leakage down to a depth of 40 m, which suggests that the permeable zone extends deeper than the results revealed by the SRT. Furthermore, this test demonstrated that the dam's right and central foundations are susceptible to leakage to the drilled depths. The SRT revealed that the central foundation, right, and left abutments of the dam are susceptible to leakage to the depth of 35 m, 30 m, and 34 m, respectively. Moreover, the kinematic analysis revealed that a section of the left abutment of the dam is susceptible to wedge mode of failure due to the intersection of JS1 and JS2. The LEM modeling of the right abutment of the dam also depicted that this section of the dam is unstable under saturated conditions which illustrates the importance of precipitation as the major slope destabilizing factor in the study area. Based on the study findings, this study recommended the use of curtain grouting to address the water tightness issue and slope angle reduction to mitigate the slope instability problem.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100230"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000686/pdfft?md5=4a8cb83d45f06467cb05d3e59e81f632&pid=1-s2.0-S2666033424000686-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141997953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Taphonomic and zooarchaeological analysis of fauna from the Howiesons Poort and post-Howiesons Poort at Klasies River main site: Examining links between the environment and subsistence behaviour in Marine Isotope Stages 4 and 3","authors":"Jerome P. Reynard ,&nbsp;Alexandra Pearson ,&nbsp;Pamela Akuku ,&nbsp;Sarah Wurz","doi":"10.1016/j.qsa.2024.100220","DOIUrl":"10.1016/j.qsa.2024.100220","url":null,"abstract":"<div><p>Marine Isotope Stages (MIS) 4 and 3 were significant periods encompassing some 50,000 years, including at least two techno-cultural entities: the Howiesons Poort (HP) and post-HP. Exploring subsistence and environmental changes during these periods may help us understand broader aspects of behavioural and occupational patterns over MIS 4 and 3. In this paper, we report on taphonomic analyses of a sample of early HP, late HP and post-HP fauna from Klasies River main site cave 1A. We use these and other faunal data to examine the links between subsistence behaviour and the environment during the HP and post-HP. The results of our analyses indicate that percussion marks are abundant in the HP, with percussion mark frequencies more prevalent in the later HP than the early HP indicating that humans were the primary accumulators of fauna in the HP. Other taphonomic data such as fracture patterns, burning and trampling marks also suggests that human activity was more prevalent in the HP than the post-HP. In contrast, in the post-HP, the prevalence of zoogenic marks on small mammal remains, and comparisons to actualistic assemblages indicate that carnivores probably contributed significantly to the post-HP assemblage. In all the samples investigated, crania dominate skeletal-part profiles. This could be a result of taphonomic bias, or it could indicate that foraging likely occurred relatively close to the site. Analyses of carcass-part utility show that marrow-extraction may have been a key subsistence strategy in the HP. In the post-HP, bone density-mediated attrition had a significant effect on fauna making it challenging to ascertain subsistence patterns, but preliminary analysis may also suggest marrow extraction in combination with other strategies.</p><p>Post-depositional taphonomic marks such as manganese staining suggest that post-HP and late HP deposits were significantly more affected by moisture than the early HP deposits. Previous investigations of large mammal data point to more closed environments in the early HP, while our data indicate that the environment in the late HP and post-HP was largely similar. In comparing our data to previously analysed micromammal proxy data, we show that major environmental changes at KRM occurred after the shift to post-HP lithic technology. However, the taphonomic data suggests a close relationship between changing subsistence strategies and the MIS4/3 transition.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100220"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000583/pdfft?md5=3f5457c9823234586ac89bbc06886974&pid=1-s2.0-S2666033424000583-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141841931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of UCS and BTS under freeze-thaw conditions in the NW himalayan rock mass using petrographic analysis and laboratory testing","authors":"Amit Jaiswal ,&nbsp;Md Shayan Sabri ,&nbsp;Amit Kumar Verma ,&nbsp;Sahil Sardana ,&nbsp;T.N. Singh","doi":"10.1016/j.qsa.2024.100225","DOIUrl":"10.1016/j.qsa.2024.100225","url":null,"abstract":"<div><p>Repeated freeze-thaw (F&amp;T) cycles substantially harm the durability of rocks, heightening the potential for landslides, rockslides, and avalanches. The current work investigates the effect of the F&amp;T cycle on rock mass (biotite schist) samples. For this purpose, 32 rock samples were prepared and gathered from eight distinct locations in the northwest Himalayan region. For each sample, petrographical analysis and laboratory testing such as uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) are investigated at repeated (0^th, 10th, 20th, and 30th) F&amp;T cycles. Additionally, machine learning (ML) sequential models such as recurrent neural networks (RNN), gated recurrent units (GRU), and bi-directional long short-term memory (Bi-LSTM) are constructed to estimate the UCS and BTS under F&amp;T conditions. Petrographical results show no change in the mineral indices, while there is a noticeable increase in aspect ratio but a significant decline in mean grain size with each successive 10th cycle, suggesting sample damage. The study also provides a comprehensive assessment of the ML models' performance, highlighting the Bi-LSTM model's superior accuracy among all models in terms of R² (0.9850) and RMSLE (0.0100) during the TR stage and R² (0.9020) and RMSLE (0.0170) during the TS stage for UCS prediction. Similarly, BTS prediction also shows superior precision, recording an R² (0.7543) and RMSLE (0.0345) during TR and R² (0.7404) and RMSLE (0.0213) during TS stages. The present study also explores the heatmap, line diagram, regression analysis, 2D kernel density plot, Taylor diagram, and DDR criterion for evaluating the model performance more clearly.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100225"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000637/pdfft?md5=40bdbf75f0dce78d6cdd9b4f3cbff1e1&pid=1-s2.0-S2666033424000637-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Last interglacial and MIS 9e relative sea-level highstands in the Central Mediterranean: a reappraisal from coastal cave deposits in the Cilento area, Southern Italy","authors":"Ilaria Isola ,&nbsp;Monica Bini ,&nbsp;Andrea Columbu ,&nbsp;Mauro Antonio Di Vito ,&nbsp;Biagio Giaccio ,&nbsp;Hsun-Ming Hu ,&nbsp;Fabio Martini ,&nbsp;Francesca Pasquetti ,&nbsp;Lucia Sarti ,&nbsp;Federica Mulè ,&nbsp;Antonio Mazzoleni ,&nbsp;Chuan-Chou Shen ,&nbsp;Giovanni Zanchetta","doi":"10.1016/j.qsa.2024.100212","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100212","url":null,"abstract":"<div><p>A revaluation of the relative sea-level (RSL) indicators in the Baia di Infreschi (Cilento, Southern Italy) supported by new 30 U/Th dating on speleothems indicates that the upper level of <em>Lithophaga</em> burrows identified by Bini et al. (2020) at ∼9 m a.s.l. and correlated to the Last Interglacial (LIG) highstand should be referred to the highstand of the MIS 9e, whereas the local RSL for the highstand of the LIG is now reassessed at 5.3 ± 0.18 m a.s.l. The upper level of the <em>Lithophaga</em> marker can be followed for ∼12 km along the coast, suggesting a substantial absence of important relative tectonic movements. In the Baia di Infreschi an additional marine indicator, a notch sealed by a flowstone dated ∼110 ka, indicates several phases of RSL stationing below the maximum highstand of the LIG. The presence of flowstones as low as 2 m a.s.l. dated to the MIS 7 shows that the highstand of MIS 7 was probably below the present sea level. All these evidences allow us to reassess the stratigraphy of some archaeological caves in the area, indicating that the sedimentary successions preserved there are older than what was previously believed.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100212"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000509/pdfft?md5=c6d63e701cc0e3a0398e88247c8111ee&pid=1-s2.0-S2666033424000509-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interpretation and implications of high-resolution hydroclimatic records of the past 7,000 years based on Gaho paleolake sediments in South Korea","authors":"Sujeong Park ,&nbsp;Jaesoo Lim ,&nbsp;Hyoun Soo Lim","doi":"10.1016/j.qsa.2024.100224","DOIUrl":"10.1016/j.qsa.2024.100224","url":null,"abstract":"<div><p>In this study, we investigated the past hydroclimate and its controlling factors over East Asia by reconstructing hydroclimate variability during the middle-to-late Holocene using rainfall-driven sedimentary features in the Gaho paleolake, Hapcheon County on the southern Korean Peninsula. Based on radiocarbon dates, median grain sizes, and elemental ratios of strontium (Sr), titanium (Ti), and zirconium (Zr) measured by high-resolution X-ray fluorescence core scanning, we tested potential indicators of past heavy rainfall. During the past 7000 years, temporal changes in median grain size and elemental ratios (Sr/Ti and Zr/Ti) were found to be similar to those in the Asian monsoonal precipitation index and sea surface temperature (SST) in the western North Pacific region, suggesting that periods with increased elemental ratios may have been influenced by intensified regional rainfall events and higher SSTs. During the past 2000 years, time series of Sr/Ti and Zr/Ti ratios in the paleolake sediments appeared to covary with a megadrought period (AD 1593–1698; 357-252 cal BP), flooding events in the 1500s, and the collapse of ancient nations in Korea and other parts of East Asia. This similarity between sedimentary records and historical events suggests considerable potential for the dating of elemental ratios in lake sediments as high-resolution analogs of past hydrological events to support historical records.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100224"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000625/pdfft?md5=9ba6675cb0dbfd50df9883cca862a7cb&pid=1-s2.0-S2666033424000625-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141850380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GIS-based MCDM approach for landslide hazard zonation mapping in east Gojjam zone, central Ethiopia","authors":"Chalachew Tesfa,&nbsp;Demeke Sewnet","doi":"10.1016/j.qsa.2024.100210","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100210","url":null,"abstract":"<div><p>Landslides are prevalent in the Ethiopian highlands, particularly in the east Gojjam zone, which is highly affected by landslide problems. This research was carried out in the east Gojjam zone, northwestern Ethiopia. The study area is part of an economically important area in the country, and it is the main source of water for the Grand Ethiopian Renaissance Dam (GERD). The main objective of this work was to undertake a detailed inventory of past landslide locations and prediction of present and future landslide hazards, as well as the preparation of a landslide zonation map in the East Gojjam zone by using the Analytical Hierarchy Process (AHP) with the GIS technique. The parameters used for this study were slope degree, slope aspect, land use and land cover, road proximity, rainfall, lithology, altitude, and river proximity. The various causative parameters were collected from the field, and suitable modifications were made to the thematic maps. Finally, the ratings for various parameters were used as the basis to prepare the LHZ map in GIS windows. The landslide susceptibility and inventory mapping were produced in the GIS environment. The results of the study show that the main driving factors for the landslide hazards in the area were river proximity, rainfall, and manmade activities. Validation of this LHZ map revealed that more than 80% of past landslides match within the \"high hazard zone\" and reasonably accepted the rationality of the adopted methodology. The considered parameters, as well as their evaluation of the production of LHZ-Map, were confirmed. The produced landslide inventory map is very important for urban planners, agricultural studies, environmentalists, and future landslide hazardous prevention and mitigation strategies.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100210"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000480/pdfft?md5=f0fae9362a436ef2d576227832b12a30&pid=1-s2.0-S2666033424000480-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slope stability modeling using limit equilibrium and finite element methods: A case study of the Adama City, Northern Main Ethiopian Rift","authors":"Tola Garo ,&nbsp;Mahlet Tesfaye ,&nbsp;Shankar Karuppannan","doi":"10.1016/j.qsa.2024.100228","DOIUrl":"10.1016/j.qsa.2024.100228","url":null,"abstract":"<div><p>Slope failure is a prominent and recurring geohazard in numerous parts of Ethiopia, including Adama City, which is located in the Northern Main Ethiopian Rift (NMER). The city is surrounded by two ridges oriented in the NNE-SSW direction, which are susceptible to slope instability. Thus, this study is aimed at modeling slope stability along these two ridges using Finite Element Method (FEM) and Limit Equilibrium Method (LEM). The modeling was carried out on slopes of multifaceted geometry composed of eluvium soil, pumice, and moderately to highly-weathered ignimbrites. Critical slope sections were identified using satellite imagery and field manifestations such as slope toe condition and slope face tilting. Their geometries were then inferred from detailed geological cross-sections based on field data. Input parameters for the modeling, such as cohesion, friction angle, and elastic modulus, were calculated via Back Analysis using the Hoek-Brown criterion while unit weight and Poisson ratio were determined from empirical equations. For soil formations, the parameters were determined via standard laboratory experiments. The modeling was then carried out under different conditions, including dry, saturated, static, and dynamic conditions. Results from both LEM and FEM models revealed that three of the four analyzed slope segments were unstable under dynamic and saturated conditions, highlighting the influence and importance of precipitation and seismicity as triggering variables. Results from both methods tend to agree when the critical slip surface passes through a single geological material in both models. However, notable differences arise when the slip surface involves multiple geological materials. Under such conditions, LEM tends to yield higher FOS values compared to FEM. The results also showed that all unstable slopes were associated with the NNE-SSW striking fault of the study area, as inferred from failure surfaces generated from both models and field data. The study concluded that unstable slopes pose a serious risk to nearby residents and infrastructure, and as a remedy, it designed and recommended coupled benching and slope flattening.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100228"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000662/pdfft?md5=43db2d59009fa58a3695d0eb6354f0ac&pid=1-s2.0-S2666033424000662-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141979783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an automated extraction and radiocarbon dating method for fossil pollen deposited in lake Motosu, Japan","authors":"","doi":"10.1016/j.qsa.2024.100207","DOIUrl":"10.1016/j.qsa.2024.100207","url":null,"abstract":"<div><p>Recently, radiocarbon (¹⁴C) dating methods using fossil pollen extracted from sediments with a flow cytometer (cell sorter) are under development. Technical limitations experienced by previous studies required extraction of grains &lt;80 μm in diameter. Thus, obtaining a sufficient mass of carbon for dating requires extracting a very large number (∼10⁵) of grains. Another challenge faced by earlier work was preventing contamination by exotic carbon during the extraction process. Here we present a novel solution to this problem by using a cell sorter with a newly designed pretreatment method and an improved extraction method. This enables us to extract large pollen fossils than was previously possible. By using grains, &gt;100 μm in diameter, such as <em>Pinus</em> sp., we have reduced the number of grains for required for ¹⁴C dating by an order of magnitude, particularly when considering the recent advances in measure ultra-small carbon masses on a single-stage accelerator mass spectrometer at the Atmosphere and Ocean Research Institute, University of Tokyo. We then apply this method to sediments recovered from Lake Motosu, which already has a very robust chronology, to evaluate the new method. Results indicate the method is successful and reveal temporal radiocarbon reservoir effects that appear related to the changes in the depositional environment and/or hydroclimate. The method presented here is widely applicable across multiple environments.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100207"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000455/pdfft?md5=3731e2edf09ad0b65cdbca421c9cd153&pid=1-s2.0-S2666033424000455-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141414245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Re-evaluating Marine Isotope Stage 5a paleo-sea-level trends from across the Florida Keys reef tract","authors":"Scarlette Hsia ,&nbsp;Lauren T. Toth ,&nbsp;Richard Mortlock ,&nbsp;Charles Kerans","doi":"10.1016/j.qsa.2024.100222","DOIUrl":"10.1016/j.qsa.2024.100222","url":null,"abstract":"<div><p>Unraveling how Global Mean Sea Level (GMSL) fluctuated during past warm periods can improve our understanding of linkages between sea-level fluctuations, orbital forcing, and ice-sheet dynamics. Current estimates of GMSL for Marine Isotope Stages (MIS) 5a and 5c — two warm intervals following the relatively well-documented MIS 5e — contain meters of uncertainty and fewer data due to several challenges. These challenges include concealment of datable in-situ coral facies by MIS 1 deposits and inaccessibility due to submergence by modern sea level. We present a comprehensive dataset based on U–Th dating and stratigraphic correlation of 23 cores totaling over 170 m of recovered coral-reef deposits across the tectonically stable Florida Keys Reef Tract (FKRT). Following detailed facies descriptions, 34 in-situ, minimally altered aragonitic coral samples (≤2.7% calcite) below the Holocene-Pleistocene boundary were targeted for U–Th geochronology. Fourteen closed-system coral U–Th ages from MIS 5a include the commonly used sea-level indicator <em>Acropora palmata</em>, but also the massive coral taxa <em>Pseudodiploria strigosa, Siderastrea siderea, Orbicella</em> spp., and <em>Porites astreoides</em>. Dating yielded ages in the range of 88–81 ka (average 2σ uncertainty of less than 200 years). These ages suggest MIS 5a reef initiation at ∼88 ka BP, a peak near 83 ka with minimum elevations between −6.0 ± 0.5 and −5.6 ± 0.5 m MSL (2σ uncertainty and subsidence-corrected), and reef termination and sea-level fall by ∼81 ka BP. Notably, the range of peak MIS 5a relative sea-level estimates of −6.5 to −5.1 m MSL are more than 2 m shallower (higher) than previous estimates of −11 to −9 m. Our higher resolution regional sea-level reconstruction across four subregions of the Florida Keys reef tract aligns with changes in July insolation at 65° N: a trend that most other records, such as deep-sea sediments, do not have the accuracy and precision to resolve. Three massive coral samples from MIS 5c, consisting of <em>Pseudodiploria clivosa</em>, and <em>Orbicella</em> spp., yielded ages in the range of 104 to 99 ka (average 2σ uncertainty less than 200 years); however, because only one sample met the closed-system criteria, our ability to estimate MIS 5c sea level is relatively limited. More empirical estimates of sea-level from the MIS 5a and MIS 5c intervals based on numerical dating of reliable local sea-level constraints are critical for GMSL calculations and relating changes in sea-level amplitude and timing to global ice volume modeling and glacio-isostatic effects, all of which can improve predictions of future sea-level changes in coastal regions.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100222"},"PeriodicalIF":2.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000601/pdfft?md5=9e0ecbfc31f797381e7ef76466c4c54c&pid=1-s2.0-S2666033424000601-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141843551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling terminal Pleistocene and Holocene forager population increase and environmental change in the Central Namib desert, Namibia","authors":"Grant S. McCall ,&nbsp;Theodore P. Marks","doi":"10.1016/j.qsa.2024.100202","DOIUrl":"https://doi.org/10.1016/j.qsa.2024.100202","url":null,"abstract":"<div><p>This paper examines the interplay of environmental change and human demographic shifts among late Pleistocene and Holocene populations in the hyper-arid context of the Central Namib Gravel plains, Western Namibia. This paper applies a structural equation modeling (SEM) approach to arid-zone hunter-gatherer mobility patterns and settlement systems based on variability among ethnographically and historically observed groups. It then applies this model in examining issues related to the Middle-to-Later Stone Age transition at the sites of Erb Tanks and the Mirabib rock shelter. This model suggests that, among modern arid-zone foragers, population density is by far the strongest factor influencing mobility and settlement systems, with higher population densities favoring longer residential site usages and shorter residential moves within smaller territories. In contrast, environmental variables having to do with annual rainfall, rainfall seasonality, and effective temperature affect mobility and settlement systems in ambiguous and statistically insignificant ways. This paper closes by arguing that regional-scale population increases signaled by various features of Later Stone Age archaeological patterning led to local population expansions in the Central Namib Desert, and that this in turn caused a range of recognizable cultural shifts that were strongly linked with adaptations to aridity.</p></div>","PeriodicalId":34142,"journal":{"name":"Quaternary Science Advances","volume":"15 ","pages":"Article 100202"},"PeriodicalIF":4.5,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666033424000406/pdfft?md5=e233f1c34372c5f9c708d940e0d74f9e&pid=1-s2.0-S2666033424000406-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141250349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}