Quaternary International最新文献

{"title":"Late Holocene submerged beachrocks in the Sea of Marmara (Tekirdağ-Altınova, NW Türkiye): Revealing the tectonic uplift rate through radiocarbon dating","authors":"Ufuk Tarı ,&nbsp;Gürsel Sunal ,&nbsp;Caroline Welte ,&nbsp;Cenk Yaltırak ,&nbsp;Orkan Özcan ,&nbsp;Melina Wertnik","doi":"10.1016/j.quaint.2024.07.007","DOIUrl":"10.1016/j.quaint.2024.07.007","url":null,"abstract":"<div><p><span>Beachrock formations represent a powerful paleo-environmental proxy in tectonically active coasts because they are ideal marker horizons for reconstructing past sea-level positions and revealing vertical uplift rates. In this study, beachrocks from the Tekirdağ-Altınova coastal area were used to model the evolution of the late </span>Holocene coastline in the northern Sea of Marmara.</p><p><span>As the Tekirdağ-Altınova coastal area is located in the tectonically active western Marmara region, this study aimed to investigate the role of tectonic processes in the late Holocene evolution of the coastal landscape in the study area by assessing long-term vertical deformation rates. To document and estimate coastal uplift, lesser known submerged beachrocks within the nearshore coastal area of the northern Sea of Marmara were analyzed with novel laser ablation (LA)–accelerator mass spectrometry (AMS) and standard </span>¹⁴<span>C-AMS techniques and correlated with late Holocene sea level variations. The preservation state of these beachrocks allowed for their identification and mapping through the use of an unmanned aerial vehicle (UAV) equipped with a high-resolution (5 cm) camera, followed by sampling via the coring method.</span></p><p>The determined ages of marine shells and calcite cements from selected samples of submerged beachrock span between 2.6 and 13.6 ky BP. These ages could be correlated with the late Holocene sea-level highstand and were used to estimate the long-term uplift rate. Based on these findings, an uplift rate of approximately 0.56–0.79 mm/yr over the last 6500 years has been suggested for the area studied.</p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"706 ","pages":"Pages 32-48"},"PeriodicalIF":1.9,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141848163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Latitudinal patterns of shifts in cladoceran communities throughout the Holocene: A paleoecological case study of northwestern Russia","authors":"Aisylu G. Ibragimova ,&nbsp;Ivan I. Krolenko ,&nbsp;Larisa A. Frolova ,&nbsp;Dmitry A. Subetto ,&nbsp;Maksim S. Potakhin ,&nbsp;Natalya A. Belkina ,&nbsp;Ivan M. Grekov ,&nbsp;Alexey A. Kotov","doi":"10.1016/j.quaint.2024.07.002","DOIUrl":"10.1016/j.quaint.2024.07.002","url":null,"abstract":"<div><p><span>Paleolimnology<span> is a rapidly expanding field within the natural sciences. To date, many scientific papers have been published focusing on studies of remains from single sediment cores<span> in specific lakes, or a few cores from the same water body. However, few previous publications have provided a comprehensive comparative analysis of taphocenosis (and maternal community) changes in different water bodies from a large </span></span></span>geographical region<span><span> during whole Holocene using multivariate statistical methods. We conducted a joined statistical analysis of data obtained as a result of the </span>cladoceran<span><span><span> analysis of the sediment samples from six cores taken along the North-South transect from the Kola Peninsula to the Karelian Region (North-West Russia). Our aim was to identify, based on quantitative statistical methods, general whole-Holocene patterns in cladoceran taphocenosis changes. All taphocenoses in all cores from six lakes can be classified into six clusters based on their species composition. Our unexpected conclusion is that different taphocoenoses are formed by the same set of species, but their proportions vary significantly. This suggests that the same species may play different functional roles in different maternal communities. During whole Holocene, we observed a single taphocenosis cluster in the Holocene core from Lake Antyukh-Lambina, and four taphocenosis clusters in the Lake Medvedevskoe, with an intermediate number of clusters in the lakes between them. Furthermore, it can be asserted that the potential for cluster changes in the core is greater for the more southern studied water bodies (0–3 clusters for northern lakes vs. 4 clusters for southern lakes). Based on our data, we hypothesize that the diversity of cladoceran associations during the Holocene was lower in Arctic/Subarctic lakes, possibly due to their formation by ubiquitous species. Our study suggests that at least some Arctic </span>lake ecosystems have remained unchanged since </span>deglaciation times. Further studies are necessary to determine if this is a general rule.</span></span></p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"708 ","pages":"Pages 58-71"},"PeriodicalIF":1.9,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141853767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occupation patterns during the Shangshan in the upper Qiantang River Basin, eastern China: A geomorphic study based on GIS","authors":"Wenjia Zhang ,&nbsp;Zhou Lin ,&nbsp;Leping Jiang ,&nbsp;Chao Ding ,&nbsp;Meiling Chen ,&nbsp;Shengchao Zhou ,&nbsp;Xiang Zhao","doi":"10.1016/j.quaint.2024.07.001","DOIUrl":"10.1016/j.quaint.2024.07.001","url":null,"abstract":"<div><p><span><span>Shangshan is the earliest Neolithic culture discovered in the lower Yangtze region and is significant as one of the origins of rice agriculture worldwide. During the Early Holocene<span>, the Shangshan human groups settled in the river basins of the upper Qiantang region and transitioned from hunter-gatherers to farmers. Little is known about the dominant factors motivating them to settle down and their occupation patterns for adapting to local environments. To address these issues, we applied an ad hoc method by coupling landform classification, geomorphic </span></span>fieldwork, accessibility analysis, and flood risk assessment. The results of geomorphic and accessibility analyses show that the ancient residents preferred to occupy the edges of the Middle Pleistocene terraces along second- and third-order streams. These locations are mainly situated in the centers of river basins and have height differences of 5–15 m, less than approximately 15-min walking distance from streams, providing them with stable residential spaces and accessible water resources. Within the 10-min territorial scope, there are always some fluvial plains near the terrace edges, indicating that the plain is another critical landform utilized by the residents. The wide plains and a plain-terrace-upland geomorphic assemblage, within 1-h and 2-h scopes, respectively, imply that the residents started to develop agricultural land while they also exploited diverse environments to ensure a plentiful food supply. Furthermore, the hydrologic analysis and assessment reveal that the residents were aware of the potential flood risks: their settlements are located at 30-min walking distance or greater from the high-order streams; most sites are exposed to low flood risks, with average percentages of unflooded territory greater than 67% and 43% in the minor and large flood scenarios, respectively; and each site has sufficient arable land with areas of 5–23 km</span>²<span> within a 1-h scope, even under the large flood scenario. Overall, these results reveal that the river basins provided favorable living environments, and the residents could flexibly manage the landscapes to ensure stable settlements and food production, thus enabling the appearance and development of a sedentary society and rice agriculture during the early Holocene. Ultimately, the methods used in this study provide an effective approach to exploring the occupation patterns of prehistoric residents in the river basins.</span></p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"702 ","pages":"Pages 48-60"},"PeriodicalIF":1.9,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implications of active Gavilgarh/Salbardi fault on the evolution of the late Quaternary landscape in Central India","authors":"B.S. Manjare ,&nbsp;G.P.Obi Reddy ,&nbsp;U.P. Meshram","doi":"10.1016/j.quaint.2024.07.003","DOIUrl":"10.1016/j.quaint.2024.07.003","url":null,"abstract":"<div><p>The morphometric indices (MI) have been calculated along the Gavilgarh/Salbardi Fault (G/SF) to investigate active deformation, tectonic uplift, and basin tilt to find out its impact on the late Quaternary landscape. To explore the tectonic intensity, we computed MI such as stream-length gradient index (SL), hypsometric integral (HI), transverse topographic symmetry factor (T), asymmetry factor (Af), basin elongation ratio (Re), mountain front sinuosity (Smf) and valley floor width to valley height ratio (Vf). The necessary field investigations were carried out on the evolution of the Quaternary landscape to ascertain the various morphometric indices. The evaluated values of SL, HI, Re, Smf, and Vf show the high uplift of the northern block exists as opposed to the southern block, and the tilt and asymmetric character of the basins are shown by T and Af values. The presence of sedimentary landscapes like Quaternary alluvium, triangular facets, natural levees, and boulder-pebbly beds, indicates that the area has recently experienced tectonic activity. The assessed values of MI with supporting field evidence proposed that the northern block is uplifted and the basins are tilted because of the effect of G/SF.</p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"702 ","pages":"Pages 34-47"},"PeriodicalIF":1.9,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141713341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Middle Pleistocene micromammals of the Bianfudong paleolithic site, Heqing, western Yunnan","authors":"Meijing Chang ,&nbsp;Qijun Ruan ,&nbsp;Qingfeng Shao ,&nbsp;Jianhui Liu ,&nbsp;Qiang Li ,&nbsp;Xijun Ni","doi":"10.1016/j.quaint.2024.05.010","DOIUrl":"10.1016/j.quaint.2024.05.010","url":null,"abstract":"<div><p>Bianfudong (pinyin for Bat Cave) is a paleolithic site that was recently discovered in Heqing, Yunnan in southwestern China. Several hominin fossils, stone artifacts and more than 69,000 mammal fossils were unearthed in 2019. The hominin fossils and stone artifacts were excavated from the upper part (layers 1–12) of the section with an age range of 180–70 ka BP. Some large mammal fossils and micromammalian remains were collected from the lower part of the section (layers 22–30), which has an age &gt;180 ka BP. This paper describes the micromammalian fossils collected from layers 25–30 and analyzes the fauna composition and paleohabitats. A total of 638 micromammal specimens represent 12 species, including 11 extant species i.e. <em>Euroscaptor longirostris</em>, <em>Blarinella wardi</em>, <em>Anourosorex squamipes</em>, <em>Crocidura vorax</em>, <em>Eothenomys</em> (<em>Anteliomys</em>) <em>chinensis</em>, <em>E.</em> (<em>A</em>.) <em>proditor</em>, <em>Apodemus chevrieri</em>, <em>Ap. draco</em>, <em>Ap. latronum</em>, <em>Micromys minutus</em>, and <em>Niviventer confucianus</em>, and one extinct species <em>Anourosorex qianensis.</em> The two arvicolid <em>Eothenomys</em> species dominate, both in the number of identified specimens and the minimum number of individuals. The composition of the Bianfudong micromammalian fauna can be compared with the faunas of Sanjiacun in Chenggong of Yunnan Province, Mawokoudong in Bijie and Xinglongdong in Fengjie, Guizhou Province. Using the random forest model with modern meteorological data, we calculated the mean annual precipitation (MAP) and the mean annual temperature (MAT) for all 11 living species in the Bianfudong. The MAP was inferred as 1008.04 mm, close to modern data in the Heqing area, while the MAT was slightly lower at 12.84 °C. The dominance of <em>Eothenomys</em> also supports a slightly cooler climate during the late Middle Pleistocene in the Heqing area.</p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"697 ","pages":"Pages 49-63"},"PeriodicalIF":1.9,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141728835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Pleistocene depositional processes of coastal aeolian deposits and their relationship with environment change on the Changxing Island of Liaodong Peninsula, northeastern China","authors":"","doi":"10.1016/j.quaint.2024.06.007","DOIUrl":"10.1016/j.quaint.2024.06.007","url":null,"abstract":"<div><p>Coastal aeolian deposits are product of the coupling between aerodynamics and coastal hydrodynamics, which is of great significance for reconstructing aeolian activities and the coastal environmental change. Here, we investigated the coastal aeolian deposits on Changxing Island, northeastern China, using geochemistry and microscopy of the minerals together with the published sedimentological data. The results showed that aeolian deposits are mainly derived from beach sands reworked by wind. Previously published Optically Stimulated Luminescence (OSL) dating results show that the deposition ages of the aeolian deposits are 41 ka, 49 ka, and 67 ka, respectively. The sedimentologic and geochemistry of aeolian deposits are sensitive to climate change. Notably, the micromorphology structure of the surface of quartz sand particles reveals the process of the coastal environment evolution. ∼41 ka, the surface of the grains is characterized by significant subaqueous environments, showing subangular with high relief, large conchoidal fracture, and V-shaped pits. These features correspond to the early sub-interstadial stage of MIS3, characterized by a warm and humid climate and sea level highstand. Under the relative sea level rise, the high rate of sand supply produced by coastal erosion contribute to aeolian deposit formation. In contrast, at 49 ka and 67 ka, the quartz grain exhibits typical aeolian environment features that exhibits subrounded with low relief, upturned plates, and dish-shaped pits, which respond to glacial periods of cold and windy conditions and sea level lowstand. The exposure of abundant sandy material, coupled with lower vegetation cover and strong East Asian winter monsoon (EAWM) contribute to higher sediment availability and sand accumulation. We therefore propose that sediment supply control by sea-level change is the primary reason for coastal aeolian sand deposition under different climatic backgrounds.</p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"697 ","pages":"Pages 38-48"},"PeriodicalIF":1.9,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-LGM glaciomarine processes revealed by inner shelf sedimentary facies analysis (Terra Nova Bay, Western Ross Sea, Antarctica)","authors":"Giulia Giorgetti ,&nbsp;Carlo Baroni ,&nbsp;Maria Cristina Salvatore ,&nbsp;Luca Gasperini ,&nbsp;Alina Polonia","doi":"10.1016/j.quaint.2024.06.012","DOIUrl":"10.1016/j.quaint.2024.06.012","url":null,"abstract":"<div><p>Understanding the depositional processes on the inner shelf of Antarctica is a significant challenge. This difficulty arises from the heterogeneity of sediment sources, their poor preservation potential due to the advance and retreat cycles of ice bodies, and the impact of relatively strong bottom currents generated by high density contrasts in the water column. These factors contribute to the overall complexity of the glacio-influenced marine environment, particularly below present-day floating ice shelves in correspondence of areas draped in sediments related to Late Pleistocene-Holocene glacial variations. These locations provide crucial information for reconstructing past glacial dynamics driven by global changes.</p><p>In this study, we present an analysis of glaciomarine deposits collected from the Western Ross Sea, offshore Mario Zucchelli Station, in a protected indentation of the Victoria Land Coast that hosts the Terra Nova Bay polynya. We conducted multi-proxy analyses on three sediment cores sampled from selected seafloor morphological units associated with fluctuations of the grounded ice, which preserve sedimentary facies representative of this distinctive depositional environment.</p><p>We identified and described six depositional facies, characterized by diagnostic sedimentological, textural and geochemical patterns. Direct observations were integrated with high-resolution geophysical data and geomorphological seafloor analysis. Our findings highlight a Late Pleistocene-Holocene depositional sequence linked to fluctuations in grounded ice, with unconformities and sedimentary patterns potentially related to climatic variations driving ice advances and retreats.</p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"697 ","pages":"Pages 64-77"},"PeriodicalIF":1.9,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141729052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quaternary geomorphological dynamics of colluvial deposits from silicophytoliths and soil micromorphology, Araripe plateau, northeast of Brazil","authors":"Rodrigo Ranulpho ,&nbsp;Antônio Carlos de Barros Corrêa ,&nbsp;Flávia Jorge de Lima ,&nbsp;Júlio Cesar Paisani","doi":"10.1016/j.quaint.2024.06.010","DOIUrl":"10.1016/j.quaint.2024.06.010","url":null,"abstract":"<div><p>Quaternary geomorphological dynamics in the lowland tropics of South America can be described from the stratigraphy of hillslope colluvium and alluvial deposits. The analysis of sediments through the identification of depositional microfeatures and biomineralized microfossils, combined with their absolute dating by optically stimulated luminescence (OSL), allow the reconstruction of paleoenvironmental conditions. The objective of this work was to investigate the dynamics of depositional processes leading to colluvial deposition in the Araripe Plateau, Northeastern Brazil, from the analysis of stratigraphic sections, using phytoliths as indicators of paleovegetation and sediment micromorphology in the identification of depositional processes. The correlation of sediments ages, ranging from the OS3 to the OS2 (Last Glacial Maximum) with phytophysiognomy indices indicated the contribution and deposition of phytoliths from an arboreal/shrubby vegetation, replaced on the surface by grass vegetation. Periods of drier climates were correlated with LGM ages, with more open vegetation composed of grasses, in synchronously with less intense geomorphological events. The micromorphological analysis revealed that the characteristics of the deposits reflect more the action of depositional processes than pedogenetic ones. The correlation of phytolithic indices with micromorphology corroborated the environmental and geomorphological dynamics of the periods dated in the stratigraphic sections.</p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"697 ","pages":"Pages 1-18"},"PeriodicalIF":1.9,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141729147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New fossil woods (upper Pleistocene) from the lower-middle Uruguay river basin (South America) reveal the past distribution of Aspidosperma (Apocynaceae)","authors":"","doi":"10.1016/j.quaint.2024.03.004","DOIUrl":"10.1016/j.quaint.2024.03.004","url":null,"abstract":"<div><p>The present work describes the taxonomic and paleobiogeographic study of two fossil woods related to extant <em>Aspidosperma</em>. The silicified specimens come from the fossil localities of Santa Ana (30°54′S, 57°55′W) and Concordia (31°19′S, 57°59′W), Entre Ríos Province, Argentina, belonging to the El Palmar Formation (Late Pleistocene). This unit represents the sedimentary body of the upper fluvial terrace generated by the Uruguay River in its middle basin in eastern Argentina. The anatomical features that distinguish the woods are growth rings delimited by axial parenchyma and fibers, semi-ring to-diffuse-porous woods; mainly solitary vessels; simple perforation plates; alternate, bordered, and vestured intervessel pits; scarce paratracheal and diffuse apotracheal axial parenchyma; homocellular, and uniseriate to-triseriate rays; non-septate fibers. Climate reconstruction modelled at the regional scale (Ecological Niche Modeling) revealed variations in macroecological diversity patterns of the nearest living relatives (<em>Aspidosperma australe</em> and <em>A. polyneuron</em>) over the last ca. 130,000 years. Optically stimulated luminescence dating of sediments from the upper part of the El Palmar Formation in the type area reveals that the unit spans from the Last Interglacial period (warm substage, MIS marine isotope stage 5a), to the penultimate interglacial (MIS 7). This period was characterized by warmer and wetter conditions than those observed today. The eco-anatomical characteristics of the fossil record reflect this type of environment. The modern analogues of the fossils studied here are now part of the forests that integrate the Atlantic forest and Araucaria forest biogeographic provinces in South America.</p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"697 ","pages":"Pages 19-37"},"PeriodicalIF":1.9,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140156023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A late glacial paleoenvironmental and climate record from the Sierra de Juarez, Baja California","authors":"Andrea Brunelle ,&nbsp;Vachel A. Carter ,&nbsp;José Delgadillo Rodríguez ,&nbsp;Vanessa Feagin ,&nbsp;Jennifer Watt","doi":"10.1016/j.quaint.2024.06.013","DOIUrl":"10.1016/j.quaint.2024.06.013","url":null,"abstract":"<div><p><span>Ciénegas are desert wetlands that are strongly correlated with the stability of the hydrologic cycle<span><span> in arid landscapes. However, these environments are particularly vulnerable to climate change, drought, water diversion, and </span>fire suppression<span><span> which all have contributed to the degradation of ciénegas along the U.S.-Mexican borderlands. Therefore, identifying the timing of precipitation patterns in this region is of particular interest because of its relationship to many ecological responses of the landscape such as </span>groundwater recharge<span><span> and fire. Here, we present the first-ever fire paleoenvironmental record from Ciénega Chimeneas, a ciénega complex in the Sierra de Juárez of Baja California. We explore how changes in the amount and seasonality of moisture affected ciénega complexes and fire activity from across the southwestern North American region over the past 45,000 years. Our record suggests that during the </span>late glacial period, 41,000–21,000 cal yr BP, the increase of </span></span></span></span><span><em>Larrea</em></span> and <span><em>Quercus</em></span> indicate an increase in summer precipitation. Subsequently, when summer precipitation increased, pollen preservation and pollen accumulation rates (PAR) also increased. Increased vegetation allowed for increased fire activity during the late glacial period. Regionally, most of the comparison sites also indicated wet conditions during the full glacial period. However, around 21,000 cal yr BP, effective moisture decreased resulting in a dramatic change in the vegetation assemblage. Specifically, the summer wet taxa disappeared, while pollen preservation and PAR decreased, suggesting a dry period until ∼14,000 cal yr BP. Little fire activity is recorded after 21,000 cal yr BP, likely due to the absence of fuels. At ∼14,000 cal yr BP, <em>Larrea</em> and <em>Quercus</em><span><span> reappear suggesting increased summer precipitation. However, the appearance of Cyperaceae and increases in grasses suggest increased winter precipitation. We suggest that the combination of summer wet and winterwet taxa ∼14,000 cal yr BP represents an increase in </span>ENSO conditions, while the summer moisture controls remained relatively constant.</span></p></div>","PeriodicalId":49644,"journal":{"name":"Quaternary International","volume":"705 ","pages":"Pages 94-103"},"PeriodicalIF":1.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}