Articoli di riviste: "Stratigraphic Holocene"

1

Genov, Ivan. "Comment on “Holocene sedimentation in the southwestern Black Sea: Interplay between riverine supply, coastal eddies of the Rim Current, surface and internal waves, and saline underflow through the Strait of Bosphorus” by O. Ankindinova, A. E. Aksu, R. N. Hiscott [Marine Geology, 420 (2020) 106092]". Review of the Bulgarian Geological Society 81, n. 2 (2020): 77–88. http://dx.doi.org/10.52215/rev.bgs.2020.81.2.6.

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Ankindinova et al. (2020) describe a series of hydrological events that have led to sedimentation and stratigraphic variations in the gradual sinking of the Black Sea shelf during the Holocene. A key aspect of the study is the attempt to provide a reliable stratigraphic basis for proving of a transgression in the basin throughout the Holocene. However, the conclusions of this approach run counter to the stratigraphic rules: redeposition and significant hiatus in the transgressive phase change of depth of sediment core location (M05-03P) – principle of superposition; merging of transgressive and regressive deposits into a common stratigraphic unit (contradicts the sequential stratigraphy). For this reason, the stability of the conclusion of Ankindinova et al. (2020) for the totally transgressive Holocene development of the Black Sea is doubtful. In addition, the study is based on the interpretation that the increase in the 87Sr /86Sr ratio is solely dependent on ocean water inflow, which is not always correct for enclosed and semi-enclosed basins.

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Krider, P. Reed. "Paleoclimatic Significance of Late Quaternary Lacustrine and Alluvial Stratigraphy, Animas Valley, New Mexico". Quaternary Research 50, n. 3 (novembre 1998): 283–89. http://dx.doi.org/10.1006/qres.1998.1997.

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Lacustrine and alluvial stratigraphic sequences in the southern Animas Valley of New Mexico allow reconstruction of late Quaternary climates. Four separate stands of late Quaternary Lake Cloverdale in the southern Animas Valley are recorded by lacustrine shoreline deposits. Soils and stratigraphic evidence show that three young lake highstands occurred during the Holocene and that a higher lake stand occurred 18,000 to 20,00014C yr B.P. Fluvial systems aggraded the southern Animas Valley during the middle to late Holocene. The late Quaternary stratigraphy shows that several periods during the late Holocene were characterized by higher effective precipitation than at any time since the last glacial maximum.

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3

Boreham, S. "The Geology of the Wicken Vision Area, lower Cam valley, Cambridgeshire, UK". Netherlands Journal of Geosciences - Geologie en Mijnbouw 92, n. 1 (aprile 2013): 47–59. http://dx.doi.org/10.1017/s0016774600000275.

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AbstractThe geology of the Wicken Vision Area in the lower Cam valley is described with reference to a stacked series of ten cross-sections through Holocene and Pleistocene deposits, and Cretaceous/Jurassic bedrock across the region. A detailed cross-section through a Holocene palaeochannel, with radiocarbon dating and pollen analyses is also presented. The structural geology of the bedrock and the stratigraphic arrangement of the Pleistocene and Holocene deposits are used to describe landscape development for the area. This study offers a new understanding of the stratigraphy and context of the Holocene, Weichselian and earlier Pleistocene deposits of the lower Cam valley, and provides a unique view of sediment architecture in valley-fill sediments at the fen edge.

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4

Taylor, Kendrick C., Richard B. Alley, Debra A. Meese, Matthew K. Spencer, Ed J. Brook, Nelia W. Dunbar, Robert C. Finkel et al. "Dating the Siple Dome (Antarctica) ice core by manual and computer interpretation of annual layering". Journal of Glaciology 50, n. 170 (2004): 453–61. http://dx.doi.org/10.3189/172756504781829864.

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AbstractThe Holocene portion of the Siple Dome (Antarctica) ice core was dated by interpreting the electrical, visual and chemical properties of the core. The data were interpreted manually and with a computer algorithm. The algorithm interpretation was adjusted to be consistent with atmospheric methane stratigraphic ties to the GISP2 (Greenland Ice Sheet Project 2) ice core, 10Be stratigraphic ties to the dendrochronology 14 C record and the dated volcanic stratigraphy. The algorithm interpretation is more consistent and better quantified than the tedious and subjective manual interpretation.

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Marochkin, A. G., A. S. Sizyov, A. Yu Yurakova, D. A. Gavrilov e K. D. Khairulina. "Stratigraphy of the Pisanaya-4 Settlement near the Tomskaya Pisanitsa Petroglyphic Site". Problems of Archaeology, Ethnography, Anthropology of Siberia and Neighboring Territories 27 (2021): 511–19. http://dx.doi.org/10.17746/2658-6193.2021.27.0511-0519.

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This article discusses some problems in relative chronology of archaeological assemblages discovered at multilayered sites at the border of the Lower Tom and Middle Tom River regions, in their stratigraphic context. The research was aimed at establishing natural stratigraphy of the Pisanaya-4 site at its different sections, conducting archaeological attribution of the series of artifacts, identifying chronological and stratigraphical features of archaeological assemblages, and evaluating the data obtained for periodization of archaeological finds from the Tom River region and Kuznetsk Depression. In total, evidence from seven sites located on the high floodplain and at the edge of the first terrace above the floodplain has been analyzed. The depth of the stratigraphic pits was 2 m. General stratification of soil mass in the floodplain zone depended on intensity and frequency of seasonal floods in the Holocene and pedogenic processes in alluvial material. A distinctive situation of multiple layers with artifacts of the Neolithic-Chalcolithic, Early and Advanced Bronze Age, Early Iron Age, and Middle Ages with pebble layers between archaeological and chronological horizons has been observed. The terrace has shown poor traces of periodic floods in the Holocene soils; alluvial deposits consisted of light brown clay loam. These sections contained some Neolithic-Chalcolithic artifacts dislocated to humus deposits and Late Paleolithic stone artifacts in the underlying clay loam alluvium. The data obtained reveals the stratigraphic nature of the Pisanaya-4 site which is new for this region and relatively rare for the entire forest-steppe belt of Western Siberia. The chronostratigraphic data on cultural and chronological assemblages of the Late Paleolithic, Early Neolithic, Late Neolithic-Chalcolithic, Early Bronze Age, Advanced Bronze Age, and Early Middle Ages at the Pisanaya-4 site is an important component for periodization of archaeological finds in the landscape context of the sites in the Tom River region.

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6

Burney, David A. "Late Quaternary Stratigraphic Charcoal Records from Madagascar". Quaternary Research 28, n. 2 (settembre 1987): 274–80. http://dx.doi.org/10.1016/0033-5894(87)90065-2.

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AbstractThe classic view regarding the cause of the extinction of at least 17 species of large mammals, birds, and reptiles in Madagascar during the late Holocene implicates human use of fire to modify the environment. However, analysis of the charcoal stratigraphy of three sediment cores from Madagascar shows that late Pleistocene and early- to mid-Holocene sediments deposited prior to human settlement often contain more charcoal than postsettlement and modern sediments. This observation, which is confirmed by independent measurements from direct assay and palynological counting techniques, suggests that widely held but previously untested beliefs concerning the importance of anthropogenic fires in late Holocene environmental changes and megafaunal extinctions of Madagascar may be based on an overly simplified version of actual prehistoric conditions. Moderate to low charcoal values characterized only the late Holocene millennia immediately prior to the presumed time of arrival of the first settlers. Human settlement is probably indicated in the stratigraphy by the sharp rise in charcoal content observed beginning ca. 1500 yr B.P. Fire appears to be a significant natural component of prehuman environments in Madagascar, but some factor, probably climate, has modulated the extent of natural burning.

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Zhou, Weijian, Zhisheng An e M. J. Head. "Stratigraphic Division of Holocene Loess in China". Radiocarbon 36, n. 1 (1994): 37–45. http://dx.doi.org/10.1017/s0033822200014302.

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Loess deposition within the Loess Plateau of China records the history of environmental change over the last 2.5 Myr. Loess-paleosol sequences of the last 10 ka, which have preserved information of global climate change, relate closely to human occupation of the area. Hence, studies of the deposition and development of Holocene loess are significant for studying environmental change and problems associated with engineering geology. We present here stratigraphic relations among four profiles from the south, west and center of the Loess Plateau. On the basis of 14C radiometric and AMS dates of organic material extracted from the paleosols, together with magnetic susceptibility measurements down each profile, we discuss Holocene stratigraphic divisions within the Loess Plateau, and suggest that the Holocene optimum, characterized by paleosol complexes, occurred between 10 and 5 ka bp. From 5 ka BP to the present, neoglacial activity is characterized by recently deposited loess.

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Boreham, Steve, e Karolina Leszczynska. "The Geology of the Middle Cam Valley, Cambridgeshire, UK". Quaternary 2, n. 3 (12 luglio 2019): 24. http://dx.doi.org/10.3390/quat2030024.

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This study offers a new understanding of the stratigraphy and context of the Pleistocene (including Elsterian and Weichselian) and Holocene deposits of the Middle Cam valley, Cambridgeshire, United Kingdom, and provides a unique and detailed view of the sediment architecture of these valley-fill and interfluve sediments. The new insights into the geology of the area, including dating, pollen analyses, and sediment architecture, are presented with reference to a series of nine cross-sections through Holocene and Pleistocene deposits, as well as Cretaceous bedrock across the region. The structural geology of the bedrock and the stratigraphic arrangement of younger deposits are used to explain the landscape evolution of the area.

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9

White, James M., e Gerald Osborn. "Evidence for a Mazama-like tephra deposited ca. 10 000 BP at Copper Lake, Banff National Park, Alberta". Canadian Journal of Earth Sciences 29, n. 1 (1 gennaio 1992): 52–62. http://dx.doi.org/10.1139/e92-007.

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Mazama tephra is a widespread mid-Holocene stratigraphic marker, dating to ca. 6845 BP, and is considered useful for the correlation of Holocene events in western North America. We present evidence from Copper Lake, Alberta, for a tephra layer that underlies Mazama tephra and appears to be a discrete tephra layer but that is indistinguishable from the conventional Mazama tephra by microprobe analysis of glass shards. Three alternative hypotheses are considered to explain this tephra underlying Mazama: in situ position of an earlier Mazama-like tephra, recycling of tephras, and settling of tephra slabs through the gyttja. The size distributions of birch pollen grains indicate that the Mazama-like tephra is in primary stratigraphic position in the early Holocene gyttja, and that sediment recycling has not destroyed the integrity of Copper Lake sediment stratigraphy. It is concluded that most probably a Mazama-like tephra was deposited between 9700 and 10 500 BP. If this in situ hypothesis is correct, the identification of a tephra as Mazama by major-element chemistry does not necessarily fix the age of the enclosing strata. Evidence to confirm the existence and plot the distribution of a Late Pleistocene – early Holocene, Mazama-like tephra is needed from other sites in northwestern America. A collateral result of this study is that ablation of valley-bottom ice in the vicinity of Castle Mountain took place prior to 10 500 BP.

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10

Aiello, Gemma. "Quaternary Lowstand Prograding Wedges of the Salento Continental Shelf (Southern Adriatic Sea, Italy): Architectural Stacking Patterns and the Control of Glacio-Eustatic Sea Level Fluctuations and Foreland Tectonic Uplift". Geosciences 13, n. 1 (22 dicembre 2022): 4. http://dx.doi.org/10.3390/geosciences13010004.

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The performance of both the tectonic uplift and of the 4th-order glacial eustatic sea level fluctuations in controlling the stratigraphic architecture of Quaternary lowstand prograding wedges of the Salento continental shelf (Southern Adriatic sea, Italy) during a time interval spanning from the Middle Pleistocene to the Holocene has been pointed out through the interpretation of high-resolution seismic reflection profiles and their correlation to the curves of the isotopic stratigraphy. Three main transgressive surfaces of erosion (RS1, RS2 and RS3) punctuate the stratigraphic architecture of the Salento continental shelf, separating Quaternary lowstand prograding wedges between them. All along the Middle Pleistocene, increasing the tectonic uplift of the Puglia offshore, combining with 4th-order glacio-eustatic variations, have dealt with the pattern of a broad forced regression prograding wedge, favoring a platform progradation of approximately 15 km. The architectural stacking patterns of the overlying Late Pleistocene and Holocene prograding wedges are controlled by 4th-order glacio-eustatic sea level changes, allowing for the formation of incomplete depositional sequences. In this period, the eustatic signature overcomes the tectonic mark, implying a decline in the uplift of the Apulian foreland in the course of the final 250 ky.

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Goman, Michelle, Arthur Joyce e Raymond Mueller. "Stratigraphic evidence for anthropogenically induced coastal environmental change from Oaxaca, Mexico". Quaternary Research 63, n. 3 (maggio 2005): 250–60. http://dx.doi.org/10.1016/j.yqres.2005.02.008.

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Previous interdisciplinary paleoenvironmental and archaeological research along the Río Verde Valley of Oaxaca, Mexico, showed that Holocene erosion in the highland valleys of the upper drainage basin triggered geomorphic changes in the river's coastal floodplain. This article uses stratigraphic data from sediment cores extracted from Laguna Pastoría, an estuary in the lower Río Verde Valley, to examine changes in coastal geomorphology potentially triggered by highland erosion. Coastal lagoon sediments contain a stratigraphically and chronologically distinct record of major hurricane strikes during late Holocene times. Three distinct storm facies are identified from sediment cores obtained from Laguna Pastoría, which indicate that profound coastal environmental changes occurred within the region and are correlated with increased sediment supplied from highland erosion. The Chione/Laevicardium facies was deposited in an open bay while the Mytella/barnacle facies and sand facies were deposited in an enclosed lagoon following bay barrier formation. We argue that highland erosion triggered major geomorphic changes in the lowlands including bay barrier formation by ∼2500 cal yr B.P. These environmental changes may have had significant effects on human populations in the region. The lagoon stratigraphy further indicates an increase in mid–late Holocene hurricane activity, possibly caused by increased El Niño frequencies.

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Heirman, Katrien, Marc De Batist, Fabien Arnaud e Jacques-Louis De Beaulieu. "Seismic stratigraphy of the late Quaternary sedimentary infill of Lac d'Armor (Kerguelen archipelago): a record of glacier retreat, sedimentary mass wasting and southern Westerly intensification". Antarctic Science 24, n. 6 (3 luglio 2012): 608–18. http://dx.doi.org/10.1017/s0954102012000466.

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AbstractLac d'Armor (49°27′S, 69°42′E) is a medium-sized, fjord-type lake located on the ‘Grande Terre’ island of the Kerguelen archipelago. A dense grid of high-resolution reflection seismic profiles was collected from this lake basin. The seismic stratigraphic facies reveal a last deglaciation to Holocene infill comparable to the seismic facies found in other glacigenic lakes all over the world. Remarkable features in the seismic stratigraphy are mounded structures found at the southern edge of both sub-basins. The sediment mounds can be interpreted as sediment drifts created by wind-induced bottom currents. The onset of the build-up of these drifts initiated at some point in the Holocene and indicates a strengthening of the southern Westerlies, which are currently the dominant winds on this island.

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McGlue, Michael M., Renato Lada Guerreiro, Ivan Bergier, Aguinaldo Silva, Fabiano N. Pupim, Victoria Oberc e Mario L. Assine. "Holocene stratigraphic evolution of saline lakes in Nhecolândia, southern Pantanal wetlands (Brazil)". Quaternary Research 88, n. 3 (24 agosto 2017): 472–90. http://dx.doi.org/10.1017/qua.2017.57.

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AbstractNhecolândia is a fossil lobe of the Taquari River megafan and a prominent geomorphic subunit of the Pantanal wetlands because of the presence of >10,000 small lakes. We investigated the stratigraphic records of three saline lakes from Nhecolândia to explore their potential as Quaternary hydroclimate archives. Radiocarbon data indicate that accumulation at two lakes was approximately continuous in the late Holocene, and chemostratigraphic variability suggests sensitivity to environmental change with multicentennial resolution. A basal sandy unit and an upper muddy unit comprise the shallow stratigraphy of each lake. A pronounced change in depositional environment from freshwater wetlands to saline lakes at ~3300–3200 cal yr BP best explains the lithofacies transition. Ephemeral freshwater wetlands formed on the abandoned megafan lobe, which was molded by deflation in the arid early Holocene. Wind-scouring of the megafan lobe generated topographically closed depressions with complex marginal sand ridges, which allowed permanent lakes to evolve when rainfall increased in the late Holocene. The lakes became highly saline and alkaline after ~910 cal yr BP, which influences biogeochemistry and aquatic ecology. The results hold implications for understanding the response of the southern Pantanal to climate change, as well as the development of pans in tropical megafan settings.

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Olson, Hilary Clement, John E. Damuth e C. Hans Nelson. "Latest Quaternary sedimentation in the northern Gulf of Mexico intraslope basin province: II — Stratigraphic analysis and relationship to glacioeustatic climate change". Interpretation 4, n. 1 (1 febbraio 2016): SC81—SC95. http://dx.doi.org/10.1190/int-2015-0111.1.

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Stratigraphic zonation of 139 piston cores from the intraslope basin province of the northern Gulf of Mexico based on the Globorotalia menardii complex and calcium carbonate fluctuations shows that the vast majority of the cores contain sediments only of Holocene (Z zone) and Late Wisconsin (Y zone, Last Glacial) age. Only 13 widely spaced cores penetrate sediments of Last Interglacial (X zone) age. Overall, sedimentation rates average approximately 13 cm for the Holocene, but they range up to 600 cm. Redeposited sediments (mass-transport deposits and/or turbidites) occur in cores from the Rio Grande Submarine Fan, the East Breaks Slide Complex, the Trinity-Brazos Turbidite System, and the Bryant Canyon Turbidite System. Stratigraphic zonation of suites of cores from these areas shows that nearly all of these deposits were emplaced during Late Wisconsin (Y zone, Last Glacial). Redeposited sediments in the Holocene (Z zone) are rare.

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Benz, Marion, Aytaç Coşkun, Irka Hajdas, Katleen Deckers, Simone Riehl, Kurt W. Alt, Bernhard Weninger e Vecihi Özkaya. "Methodological Implications of New Radiocarbon Dates from the Early Holocene Site of Körtik Tepe, Southeast Anatolia". Radiocarbon 54, n. 3-4 (2012): 291–304. http://dx.doi.org/10.1017/s0033822200047081.

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One of the greatest challenges of contemporary archaeology is to synthesize the large amount of radiocarbon and archaeological data into a useful dialogue. For the late Epipaleolithic and the Early Neolithic of the Near East, many 14C ages have been published without precise stratigraphic documentation. Consequently, for archaeological age models we often must use some more elementary approaches, such as probabilistic summation of calibrated ages. The stratigraphy of Körtik Tepe allows us for the first time to study an extended series of 14C ages of the earliest Holocene. In particular, we are able to analyze the data according to stratigraphic position within a well-documented profile. However, because of a plateau in the 14C age calibration curve at the transition from the Younger Dryas to the Early Holocene, dates of this period can be interpreted only if an extended sequence of dates is available. Due to problems remaining in the calibration procedure, the best way to achieve an interpretation is to compare the results of different 14C calibration software. In the present paper, we use the results of the calibration programs OxCal and CalPal. This approach has important implications for future age modeling, in particular for the question of how to date the transition from the Epipaleolithic to the PPNA precisely and accurately.

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Shuman, Bryan N., Paul Pribyl e Jacob Buettner. "Hydrologic changes in Colorado during the mid-Holocene and Younger Dryas". Quaternary Research 84, n. 2 (settembre 2015): 187–99. http://dx.doi.org/10.1016/j.yqres.2015.07.004.

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The stratigraphy of Upper Big Creek Lake (UBC), an overflowing lake in northern Colorado, indicates that the lake responded to a series of hydroclimatic changes over the past ~ 13,000 years. Modern sediments in eight comparator lakes from across Wyoming and Colorado facilitate the stratigraphic interpretation by showing that littoral sediments have exponentially higher sand content, lower loss-on-ignition (LOI), and lower net accumulation rates than off-shore sediments. Sand layers in two near-shore cores from UBC share the characteristics of the modern littoral sediments (> 80% sand, < 5% LOI, and < 10 cm/ka accumulation rates), and indicate that UBC was > 1.9 m below its outlet from 12,500 to 11,300 and from 7500 to 2100 cal yr BP. Ground-penetrating radar (GPR) profiles consistent with the low-water episodes show correlative sand layers and submerged wave-cut scarps around the lake margin. The stratigraphic features correlate with those formed in the comparator lakes during extensive droughts at > 11,300, 6900–6000, and 4800–3400 cal yr BP as well as a series of north-south anti-phased droughts between 5800 and 1200 cal yr BP. Lake closure at UBC amplified the local changes, and demonstrates that climate changes can increase the extent of intermittent streamflow in the Rocky Mountains relative to today.

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Foit, Franklin F., e Peter J. Mehringer. "Holocene tephra stratigraphy in four lakes in southeastern Oregon and northwestern Nevada, USA". Quaternary Research 85, n. 2 (marzo 2016): 218–26. http://dx.doi.org/10.1016/j.yqres.2015.12.008.

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To better understand the regional tephra stratigraphy and chronology of northern Nevada and southern Oregon, tephras in archived cores, taken as part of the Steens Mountain Prehistory Project from four lakes, Diamond Pond, Fish and Wildhorse lakes in southeastern Oregon and Blue Lake in northwestern Nevada, were reexamined using more advanced electron microprobe analytical technology. The best preserved and most complete core from Fish Lake along with Wildhorse Lake hosted two tephras from Mt. Mazama (Llao Rock and the Climactic Mazama), a mid-Holocene basaltic tephra from Diamond Craters, Oregon, two Medicine Lake tephras and an unexpected late Holocene Chaos Crags (Mt. Lassen volcanic center) tephra which was also found in the other lakes. Blue Lake was the only lake that hosted a Devils Hill tephra from the Three Sisters volcano in west central Oregon. Another tephra from the Three Sisters Volcano previously reported in sediments of Twin Lakes in NE Oregon, has now been confirmed as Rock Mesa tephra. The Chaos Crags, Devils Hill and Rock Mesa tephras are important late Holocene stratigraphic markers for central and eastern Oregon and northwestern Nevada.

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Ortega-Ramírez, Jose R., Alfonso Valiente-Banuet, Jaime Urrutia-Fucugauchi, Carlos A. Mortera-Gutiérrez e Guillermo Alvarado-Valdez. "Paleoclimatic changes during the Late Pleistocene - Holocene in Laguna Babícora, near the Chihuahuan Desert, México". Canadian Journal of Earth Sciences 35, n. 10 (1 ottobre 1998): 1168–79. http://dx.doi.org/10.1139/e98-060.

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The paleoclimatic variability of northern Mexico since the Late Wisconsinan is determined from sedimentological, geochemical, and stratigraphic studies of the lacustrine sequence of Laguna Babícora (29.4°N, 107.7°W; elevation 2100 m asl). Chronological control is based on 13 radiocarbon dates (6 from this study and 7 previously reported) from four stratigraphic profiles that cover a range from 16 342 to 2800 BP. Two major periods of increased humidity are recognized by lake-level variation during the Late Wisconsinan and early Holocene. The Late Wisconsinan humid period may be related to jet stream migration to southerly latitudes and the influence of the mobile polar high. This period has been identified in the sedimentary record of El Diablo profile with a radiocarbon date of 16 342 ± 201 BP. The early Holocene humid period is recorded in El Diablo (10 976 ± 115 BP) and Cano profiles (9614 ± 130 BP). It is interpreted as a result of the Younger Dryas climatic anomaly characterized by a temperature decrease and cold paleoclimatic conditions similar to those for the Late Wisconsinan. The early Holocene was followed by an overall gradual drying that reached a maximum around 6000 BP, during the middle Holocene. For the late Holocene evidence of widespread erosion, sedimentation changes, flooded surfaces, and paleosoils indicates that Laguna Babícora was subjected to short-term climatic changes.

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Dura, Tina, Charles M. Rubin, Harvey M. Kelsey, Benjamin P. Horton, Andrea Hawkes, Christopher H. Vane, Mudrik Daryono, Candace Grand Pre, Tyler Ladinsky e Sarah Bradley. "Stratigraphic record of Holocene coseismic subsidence, Padang, West Sumatra". Journal of Geophysical Research: Solid Earth 116, B11 (novembre 2011): n/a. http://dx.doi.org/10.1029/2011jb008205.

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Gale, SJ, e PG Hoare. "The stratigraphic status of the Anthropocene". Holocene 22, n. 12 (6 luglio 2012): 1491–94. http://dx.doi.org/10.1177/0959683612449764.

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The term Anthropocene was coined to describe the present geological epoch, in which human activity dominates many of the processes acting on the surface of the Earth. The expression has been widely adopted, but remains informal and lacks precise definition. There have been several attempts to establish formal stratigraphic markers to define the start of the Anthropocene. Most recently, Certini and Scalenghe (Certini G and Scalenghe R (2011) Anthropogenic soils are the golden spikes for the Anthropocene. The Holocene 21: 1269–1274) have argued that the best markers are anthropogenic soils and that these may be used to identify the base of the Anthropocene in stratigraphic sequences. Unfortunately, soils fail to meet many of the criteria required for the establishment of stratigraphic ‘golden spikes’. Their preservation potential is poor, many stratigraphically important environments do not experience pedogenesis and anthrosols do not always provide the stratigraphically lowest marker of human impact. In addition, there are practical and theoretical difficulties in defining the base of anthrosols and thus in identifying the start of the Anthropocene. More generally, the worldwide diachroneity of human impact makes it impossible to establish a single chronological datum for the epoch, raising questions about the value of stratigraphic methods in defining the base of the Anthropocene. More significantly, much of the work undertaken on the Anthropocene lies beyond stratigraphy, and a stratigraphic definition of this epoch may be unnecessary, constraining and arbitrary. It is not clear for practical purposes whether there is any real need for a golden spike at the base of the Anthropocene. The global stratigraphic approach may prove of limited utility in studies of human environmental impact.

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INOZEMTSEV, Yu I., O. O. PARISHEV, M. O. MASLAKOV, O. M. RYBAK e L. V. STUPINA. "Stratigraphy of the Upper Pleistocene<Holocene deposits of the Black and Azov seas". Geology and Mineral Resources of World Ocean 17, n. 2 (2021): 34–53. http://dx.doi.org/10.15407/gpimo2021.02.034.

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The results of comparison of stratigraphic sections of Upper Pleistocene-Holocene sediments of the Black and Azov Seas, the main stratotypic areas: the Kerch Strait, the northwestern shelf of the Black Sea, the Azov Sea and its southern shores. It was established that in the post-Karangate time, as a result of fluctuations in the level of the World Ocean and the Ponto-Caspian basin connected with it through the Bosporus Strait, the character of sedimentation, and above all, the distribution in it of Mediterranean and Caspian mollusc complexes is the main criterion for the character of sedimentation and correlation of stratigraphic horizons. It has been established that the Kerch Strait presents a complex section formed by repeated alternation of marine and river sediments with their accompanying complex of mollusks, which served as the basis for the separation of such stratigraphic horizons as Surozh, Alan, Gorkan, Enikale. In other parts of marine areas similar or close to them types of sediments are called Kazantip in the Azov Sea and Tarhankut in the Karkinit Gulf of the northwestern shelf of the Black Sea. The stratigraphic correlation of different facies sediments in different parts of the shelf of the Black and Azov Seas requires further more detailed study of sedimentation conditions, with regard to the timing of the Caspian fauna representatives in the Upper Pleistocene-Holocene sediments of the Azov-Black Sea basin.

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Hart, Isaac, Kaylee B. Jones, Andrea Brunelle, Jennifer DeGraffenried, Charles G. Jack Oviatt, Barbara Nash, Daron Duke e D. Craig Young. "BUILDING A MASTER CHRONOLOGY FOR THE WESTERN LAKE BONNEVILLE BASIN WITH STRATIGRAPHIC AND ELEMENTAL DATA FROM MULTIPLE SITES, USA". Radiocarbon 64, n. 1 (febbraio 2022): 69–85. http://dx.doi.org/10.1017/rdc.2022.3.

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ABSTRACTWe present a novel approach to developing a unified radiocarbon-based chronology for multiple sediment cores from a location where radiocarbon dating is challenging. We used 36 radiocarbon ages from eight terminal Pleistocene and Holocene sediment cores with correlated stratigraphies. Stratigraphic correlation was accomplished using a combination of high-resolution photography, high-resolution X-ray fluorescence-based elemental composition data, and volcanic tephra identification. Results show that despite problems associated with potential contamination or radiocarbon reservoir effect, a useful age-depth model has been created for the correlated lacustrine sections of these eight sediment cores, providing chronological controls for future paleoenvironmental analyses of the cores.

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Zhou, Weijian, Zhisheng An, A. J. T. Jull, D. J. Donahue e M. J. Head. "Reappraisal of Chinese Loess Plateau Stratigraphic Sequences Over the Last 30,000 Years: Precursors of an Important Holocene Monsoon Climatic Event". Radiocarbon 40, n. 2 (1997): 905–13. http://dx.doi.org/10.1017/s0033822200018877.

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Through the establishment of radiocarbon chronozones relating common geological events within lacustrine and eolian sediments from five profiles representative of loess yuan (tablelands), river valley and northwest margin features of the Loess Plateau, we propose a series of stratigraphic divisions within the last 30 ka. The focus of this detailed study involves stratigraphic relationships contributing to evidence of Younger Dryas events, with the recognition of cold-dry, cool-wet and cold-dry periods represented within the Heiheze silt, Midiwan peat and Liushuwan eolian sand. The stratigraphic profiles reflect century-scale fluctuations of the East Asian monsoons. The precursor events enable us to place the Pleistocene/Holocene boundary at 10,000 bp.

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24

Neme, Gustavo, Marcelo Zárate, María de la Paz Pompei, Fernando Franchetti, Adolfo Gil, Miguel Giardina, Viviana P. Seitz, M. Laura Salgán, Cinthia Abbona e Fernando Fernández. "Population Dynamics and Human Strategies in Northwestern Patagonia". Documenta Praehistorica 48 (10 settembre 2021): 2–21. http://dx.doi.org/10.4312/dp.48.15.

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In this paper we evaluate the role of human strategies in the Andean Piedmont from northern Patagonia across the Holocene. Specifically, we present the analysis of the Early Holocene-Late Holocene archaeological record of Salamanca cave (Mendoza-Argentina). We identified technological changes that occurred during the Late Holocene and the implications of a human occupation hiatus in the Middle Holocene. We follow a multiproxy approach by the analysis of radiocarbon dates, archaeofaunal remains, ceramic, lithics and XRF obsidian sourcing. We also discuss a detailed stratigraphic sequence by geomorphological descriptions, the construction of a radiocarbon sequence model and summed probability distributions, compared with other archaeological sites in the region. We conclude that after the Middle Holocene archaeological hiatus, human populations grew while guanaco populations dropped. The imbalance between demography and resources boosted the incorporation of new technologies such as ceramics and the bow and arrow, allowing people to exploit lower-ranked resources.

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25

Huckleberry, Gary, Charlotte Beck, George T. Jones, Amy Holmes, Michael Cannon, Stephanie Livingston e Jack M. Broughton. "Terminal Pleistocene/Early Holocene Environmental Change at the Sunshine Locality, North-Central Nevada, U.S.A." Quaternary Research 55, n. 3 (maggio 2001): 303–12. http://dx.doi.org/10.1006/qres.2001.2217.

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AbstractSedimentological, faunal, and archaeological investigations at the Sunshine Locality, Long Valley, Nevada reveal a history of human adaptation and environmental change at the last glacial–interglacial transition in North America's north-central Great Basin. The locality contains a suite of lacustrine, alluvial, and eolian deposits associated with fluvially reworked faunal remains and Paleoindian artifacts. Radiocarbon-dated stratigraphy indicates a history of receding pluvial lake levels followed by alluvial downcutting and subsequent valley filling with marsh-like conditions at the end of the Pleistocene. A period of alluvial deposition and shallow water tables (9,800 to 11,000 14C yr B.P.) correlates to the Younger Dryas. Subsequent drier conditions and reduced surface runoff mark the early Holocene; sand dunes replace wetlands by 8,000 14C yr B.P. The stratigraphy at Sunshine is similar to sites located 400 km south and supports regional climatic synchroneity in the central and southern Great Basin during the terminal Pleistocene/early Holocene. Given regional climate change and recurrent geomorphic settings comparable to Sunshine, we believe that there is a high potential for buried Paleoindian features in primary association with extinct fauna elsewhere in the region yet to be discovered due to limited stratigraphic exposure and consequent low visibility.

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26

Winski, Dominic A., Tyler J. Fudge, David G. Ferris, Erich C. Osterberg, John M. Fegyveresi, Jihong Cole-Dai, Zayta Thundercloud et al. "The SP19 chronology for the South Pole Ice Core – Part 1: volcanic matching and annual layer counting". Climate of the Past 15, n. 5 (8 ottobre 2019): 1793–808. http://dx.doi.org/10.5194/cp-15-1793-2019.

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Abstract. The South Pole Ice Core (SPICEcore) was drilled in 2014–2016 to provide a detailed multi-proxy archive of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. Interpretation of these records requires an accurate depth–age relationship. Here, we present the SPICEcore (SP19) timescale for the age of the ice of SPICEcore. SP19 is synchronized to the WD2014 chronology from the West Antarctic Ice Sheet Divide (WAIS Divide) ice core using stratigraphic matching of 251 volcanic events. These events indicate an age of 54 302±519 BP (years before 1950) at the bottom of SPICEcore. Annual layers identified in sodium and magnesium ions to 11 341 BP were used to interpolate between stratigraphic volcanic tie points, yielding an annually resolved chronology through the Holocene. Estimated timescale uncertainty during the Holocene is less than 18 years relative to WD2014, with the exception of the interval between 1800 to 3100 BP when uncertainty estimates reach ±25 years due to widely spaced volcanic tie points. Prior to the Holocene, uncertainties remain within 124 years relative to WD2014. Results show an average Holocene accumulation rate of 7.4 cm yr−1 (water equivalent). The time variability of accumulation rate is consistent with expectations for steady-state ice flow through the modern spatial pattern of accumulation rate. Time variations in nitrate concentration, nitrate seasonal amplitude and δ15N of N2 in turn are as expected for the accumulation rate variations. The highly variable yet well-constrained Holocene accumulation history at the site can help improve scientific understanding of deposition-sensitive climate proxies such as δ15N of N2 and photolyzed chemical compounds.

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27

Wright, David K., Steven L. Forman, Michael R. Waters e John C. Ravesloot. "Holocene eolian activation as a proxy for broad-scale landscape change on the Gila River Indian Community, Arizona". Quaternary Research 76, n. 1 (luglio 2011): 10–21. http://dx.doi.org/10.1016/j.yqres.2011.04.008.

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AbstractEolian sediments are common within the middle Gila River Valley, southern Arizona, and reflect variability in eolian and fluvial processes during the late Holocene. This study focuses on deciphering the stratigraphic record of eolian deposition and associated luminescence dating of quartz extracts by single aliquot regeneration (SAR) protocols. Stratigraphic assessment coupled with luminescence ages indicates that there are four broad eolian depositional events at ca. 3145 ± 220 yr, 1950–1360 yr, 800 ± 100 yr, and 690–315 yr. This nascent chronology, correlated with regional archeological evidence and paleoclimate proxy datasets, leads to two general conclusions: (1) loess deposits, transverse-dune formation and sand-sheet deposition in the late Holocene are probably linked to flow variability of the Gila River, though the last two events are concordant with regional megadroughts; and (2) the stability of eolian landforms since the 19th century reflects the lack of eolian sediment supply during a period of fluvial incision, resulting in Entisol formation on dunes. The prime catalyst of eolian activity during the late Holocene is inferred to be sediment supply, driven by climate periodicity and variable flow within the Gila River catchment.

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28

Riehle, James R. "Heterogeneity, Correlatives, and Proposed Stratigraphic Nomenclature of Hayes Tephra Set H, Alaska". Quaternary Research 41, n. 3 (maggio 1994): 285–88. http://dx.doi.org/10.1006/qres.1994.1032.

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AbstractSeveral Holocene tephra deposits of Hayes volcano constitute a marker horizon in southern and east-central Alaska. Their identification is aided by high amphibole/pyroxene ratio and biotite in trace amounts, unique among Holocene tephra deposits of the region. However, correlations are obscured by chemical heterogeneity of the glass which occurs at a scale less than the size of a lapilli. Single-shard analyses confirm that the heterogeneity is due neither to fractionation nor to plagioclase microlites. The heterogeneity may be due to mixing of magmas prior to eruption. It is proposed that the deposits be informally called Hayes tephra set H.

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29

Mahaney, William C. "Holocene glacial sequence and soils of stratigraphic importance, Mer de Glace, Western Alps, France". Zeitschrift für Geomorphologie 35, n. 2 (8 agosto 1991): 225–37. http://dx.doi.org/10.1127/zfg/35/1991/225.

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30

Latypova, E. K., e B. L. Yakheemovich. "Geochronology of the Pleistocene and Holocene in the Fore-Urals". Radiocarbon 35, n. 3 (1993): 441–47. http://dx.doi.org/10.1017/s003382220006046x.

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The paper presents the results for the 14C dating obtained recently in the Laboratory of the Institute of Geology, Ufa Science Centre, Russian Academy of Science, on the basis of megafaunal bones, peats, wood and mollusk shells. Dates are reported in stratigraphic sequence from the Late Würmian to the Holocene.

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31

Mikharevich, M. V., e A. V. Shpansky. "PROBLEMS OF AGE AND GENETIC DIAGNOSTICS OF QUATERNARY DEPOSITS IN THE VALLEY OF THE YENISEI RIVER MIDDLE COURSE (YENISEI – LOWER ANGARA STRATIGRAPHIC REGION AND THE MINUSINSK BASINS AREA)". Geology and mineral resources of Siberia, n. 10s (dicembre 2021): 57–68. http://dx.doi.org/10.20403/2078-0575-2021-10c-57-68.

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The article is devoted to the state of stratigraphic exploration maturity of the Eopleistocene – Neo-Рleistocene Quaternary deposits on the boundary of mountain and plain territories in the non-glacial area. The material analysis shows an inadequate rationale of the existing stratigraphic schemes, according to which the ladder of alluvial terraces of these territories was formed sequentially during the Eopleistocene, Neo-Pleistocene and Holocene. The revising of representative sections was carried out, the provision of them with geochronological data, the accuracy of age and genetic diagnostics were evaluated.

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32

Kurfurst, P. J., e S. R. Dallimore. "Engineering geology of nearshore areas off Richards Island, N.W.T.: a comparison of stable and actively eroding coastlines". Canadian Geotechnical Journal 28, n. 2 (1 aprile 1991): 179–88. http://dx.doi.org/10.1139/t91-025.

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Nearshore areas off northern Richards Island can be expected to show considerable variability in lithology, strengths, and geothermal setting both in a temporal and a spatial sense. Drilling and laboratory studies carried out along onshore–offshore transects at a stable coastal site and an actively eroding coastal site have identified six major stratigraphic units of Holocene and pre-Holocene (Wisconsinan) age. The main factors controlling the geotechnical properties of these sediments and their distribution are the occurrence of shallow permafrost beneath areas seasonally covered by landfast sea ice, rapid degradation of permafrost in areas farther offshore, ice content of thawing pre-Holocene sediments, and variability in coastal processes. Key words: nearshore deposits, engineering geology, permafrost, physical properties, acoustic properties.

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33

Horton, Benjamin. "Stratigraphic evidence for an early Holocene earthquake in Aceh, Indonesia". Quaternary International 279-280 (novembre 2012): 207. http://dx.doi.org/10.1016/j.quaint.2012.08.394.

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34

Grand Pre, Candace A., Benjamin P. Horton, Harvey M. Kelsey, Charles M. Rubin, Andrea D. Hawkes, Mudrik R. Daryono, Gary Rosenberg e Stephen J. Culver. "Stratigraphic evidence for an early Holocene earthquake in Aceh, Indonesia". Quaternary Science Reviews 54 (ottobre 2012): 142–51. http://dx.doi.org/10.1016/j.quascirev.2012.03.011.

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35

Korus, Jesse T., e Christopher R. Fielding. "Asymmetry in Holocene river deltas: Patterns, controls, and stratigraphic effects". Earth-Science Reviews 150 (novembre 2015): 219–42. http://dx.doi.org/10.1016/j.earscirev.2015.07.013.

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36

Hansen, Louise, Raymond Eilertsen, Inger-Lise Solberg e Kåre Rokoengen. "Stratigraphic evaluation of a Holocene clay-slide in Northern Norway". Landslides 4, n. 3 (20 gennaio 2007): 233–44. http://dx.doi.org/10.1007/s10346-006-0078-4.

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37

Allen, Wai K., Kenneth D. Ridgway, J. A. Benowitz, T. S. Waldien, S. M. Roeske, P. G. Fitzgerald e R. J. Gillis. "Neogene sedimentary record of the evolution of a translated strike-slip basin along the Denali fault system: Implications for timing of displacement, composite basin development, and regional tectonics of southern Alaska". Geosphere 18, n. 2 (8 febbraio 2022): 585–615. http://dx.doi.org/10.1130/ges02435.1.

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Abstract Analysis of the late Miocene to Holocene McCallum sedimentary basin, located along the south side of the eastern Denali fault system, provides a better understanding of strike-slip basin evolution, timing of displacement on the Denali fault, and tectonics of the southern Alaska convergent margin. Analysis of the McCallum basin utilizing measured stratigraphic sections, lithofacies analyses, and 40Ar/39Ar tephra ages documented a 564-m-thick, two-member stratigraphy. Fine-grained, lacustrine-dominated environments characterized deposition of the lower member, and coarse-grained, stream-dominated alluvial-fan environments characterized deposition of the upper member. The 40Ar/39Ar dating of tephras indicated that the lower member was deposited from 6.1 to 5.0 Ma, and the upper member was deposited from 5.0 to 3.8 Ma. Our stratigraphic analysis of the McCallum basin illuminates the development of a composite strike-slip basin, with the deposition of the lower member occurring along a transtensional fault section, and deposition of the upper member occurring along a transpressional fault section. This change in depositional and tectonic settings is interpreted to reflect ~79–90 km of transport of the basin along the Denali fault system based on Pleistocene–Holocene slip rates. Previous studies of the timing of Cenozoic displacement on the Denali fault system utilizing sedimentary records emphasized a Paleogene component; our findings, however, also require a significant Neogene component. Neogene strike-slip displacement and basin development along the Denali fault system were broadly coeval with development of high topography and related clastic wedges across southern Alaska in response to flat slab subduction of the Yakutat microplate.

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38

Wheeler, A. J., e M. P. Waller. "The Holocene lithostratigraphy of Fenland, eastern England: a review and suggestions for redefinition". Geological Magazine 132, n. 2 (marzo 1995): 223–33. http://dx.doi.org/10.1017/s0016756800011766.

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AbstractThe Fenland basin is filled with unconsolidated Holocene marine and freshwater deposits. Stratigraphic studies of the basin date back to 1877. This paper reviews the various lithostratigraphic schemes which have been proposed. Particular attention is paid to the presently accepted lithostratigraphy. Examples and a case study of a newly surveyed area are used to highlight its failings. Many of the difficulties experienced in Fenland are common to problems of lithostratigraphic classification in coastal lowland environments, as is demonstrated by reference to recent debate in the southeastern North Sea. In Fenland, as a result of the shortcomings of the various schemes, it is proposed that a new lithostratigraphy with formal stratotypes is devised. Suggestions are made as to the form this new stratigraphy could take. In the meantime, an informal lithostratigraphy should be adopted which has no regional or chronostratigraphic connotations.

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39

Demurtas, Luca, Luigi Bruno, Stefano Lugli e Daniela Fontana. "Evolution of the Po–Alpine River System during the Last 45 Ky Inferred from Stratigraphic and Compositional Evidence (Ostiglia, Northern Italy)". Geosciences 12, n. 9 (13 settembre 2022): 342. http://dx.doi.org/10.3390/geosciences12090342.

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The stratigraphic and compositional study of three sediment cores recovered close to the Po River near Ostiglia provides clues on changes in fluvial dynamics at the transition from the last glacial to the present interglacial. Upper Pleistocene units are dominated by sands with high content in volcanic lithics, denoting high sediment supply from the south-Alpine fluvio-glacial tributary system. The Early–Mid Holocene unit, peat-rich and barren in fluvial sands, results from low sediment supply and waterlogging, encompassing the maximum marine ingression. The Late Holocene unit, characterized by fluvial-channel sands with lower content in volcanics and relatively abundant metamorphic lithics, records the Po River sedimentation since the Late Bronze Age. Late Holocene sands show a lower content in siliciclastic lithic fragments (supplied mainly by Apennine tributaries) compared to modern Po River sands. This distinctive composition could reflect the diversion of Apennine sediments into a southern Po River branch during the Late Bronze Age and into an Apennine collector flowing south of Ostiglia during Roman times and the Middle Ages. The integrated stratigraphic-compositional methods used in this study permitted to reconstruct the major climate-related changes in sediment dispersal and may be potentially applied to other alluvial and coastal settings.

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40

Nordt, Lee. "Late quaternary alluvial stratigraphy of a low-order tributary in central texas, USA and its response to climate and sediment supply". Quaternary Research 62, n. 3 (novembre 2004): 289–300. http://dx.doi.org/10.1016/j.yqres.2004.07.004.

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This paper presents the first comprehensive late Quaternary alluvial stratigraphic study of a low-order tributary in central Texas, using Cowhouse Creek as a case study. The late Pleistocene Jackson (JA) alluvium forms the elevated T2 terrace. The entrenched Holocene valley is filled with the buried Georgetown (GT) alluvium (approximately 11,000 to 8000 14C yr B.P.) and associated Royalty paleosol, and the surficially exposed Fort Hood (FH) alluvium (approximately 7000 to 5000 14C yr B.P.) and West Range (WR) alluvium (approximately 4200 to 600 14C yr B.P.) forming the broad T1 terrace. The Ford (FO) alluvium (<600 14C yr B.P.) forms the modern T0 floodplain entrenched into T1. Conditioned by cooler and wetter climates, Cowhouse Creek was characterized by relatively high base flow and low sediment supply during deposition of the JA and GT alluvium. Appreciable upland soil erosion ensued during the middle Holocene in response to warmer climate conditions, resulting in widespread valley filling by the FH alluvium. Deposition of the late Holocene WR and F0 alluvium was characterized by diminished sediment storage during relatively stable climate conditions. The temporal alluvial stratigraphic framework of the bedrock-confined Cowhouse Creek valley is out of phase with the alluvial sequence in the larger Brazos River valley.

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41

Nawrot, Rafał, Daniele Scarponi, Michele Azzarone, Troy A. Dexter, Kristopher M. Kusnerik, Jacalyn M. Wittmer, Alessandro Amorosi e Michał Kowalewski. "Stratigraphic signatures of mass extinctions: ecological and sedimentary determinants". Proceedings of the Royal Society B: Biological Sciences 285, n. 1886 (12 settembre 2018): 20181191. http://dx.doi.org/10.1098/rspb.2018.1191.

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Abstract (sommario):

Stratigraphic patterns of last occurrences (LOs) of fossil taxa potentially fingerprint mass extinctions and delineate rates and geometries of those events. Although empirical studies of mass extinctions recognize that random sampling causes LOs to occur earlier than the time of extinction (Signor–Lipps effect), sequence stratigraphic controls on the position of LOs are rarely considered. By tracing stratigraphic ranges of extant mollusc species preserved in the Holocene succession of the Po coastal plain (Italy), we demonstrated that, if mass extinction took place today, complex but entirely false extinction patterns would be recorded regionally due to shifts in local community composition and non-random variation in the abundance of skeletal remains, both controlled by relative sea-level changes. Consequently, rather than following an apparent gradual pattern expected from the Signor–Lipps effect, LOs concentrated within intervals of stratigraphic condensation and strong facies shifts mimicking sudden extinction pulses. Methods assuming uniform recovery potential of fossils falsely supported stepwise extinction patterns among studied species and systematically underestimated their stratigraphic ranges. Such effects of stratigraphic architecture, co-produced by ecological, sedimentary and taphonomic processes, can easily confound interpretations of the timing, duration and selectivity of mass extinction events. Our results highlight the necessity of accounting for palaeoenvironmental and sequence stratigraphic context when inferring extinction dynamics from the fossil record.

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42

Reyes, Alberto V., e John J. Clague. "Stratigraphic evidence for multiple Holocene advances of Lillooet Glacier, southern Coast Mountains, British Columbia". Canadian Journal of Earth Sciences 41, n. 8 (1 agosto 2004): 903–18. http://dx.doi.org/10.1139/e04-039.

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Holocene lateral moraines in the Coast Mountains of British Columbia are commonly composed of multiple drift units related to several glacier advances. In this paper, we document lateral moraine stratigraphy at Lillooet Glacier in the southern Coast Mountains. Five tills, separated by laterally extensive paleosols and layers of large woody debris, were found in three cross-sectional exposures through the northeast lateral moraine and two shallow gullies incised into its steep proximal face. Eighteen new radiocarbon ages constrain the timing of five separate advances of Lillooet Glacier: (1) prior to 3000 14C years BP; (2) ~3000 14C years BP; (3) ~2500 14C years BP; (4) ~1700 to 1400 14C years BP; and (5) during the Little Ice Age (LIA), after 470 14C years BP. The Lillooet Glacier chronology is broadly synchronous with other glacier records from the Coast Mountains. These records collectively demonstrate climate variability at higher frequencies during the late Holocene than is apparent from many paleoecological reconstructions. Reconstructions of glacier fluctuations are often hampered by poor preservation of landforms that predate the extensive LIA advances of the latest Holocene. Our results highlight the potential of lateral moraine stratigraphy for reconstructing these earlier events.

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43

Rahimzadeh, Neda, Tobias Sprafke, Christine Thiel, Birgit Terhorst e Manfred Frechen. "A comparison of polymineral and K-feldspar post-infrared infrared stimulated luminescence ages of loess from Franconia, southern Germany". E&G Quaternary Science Journal 70, n. 1 (8 febbraio 2021): 53–71. http://dx.doi.org/10.5194/egqsj-70-53-2021.

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Abstract. Loess-paleosol sequences (LPSs) are essential records for reconstructing Quaternary paleoenvironments. No previous study has provided numerical chronologies of loess in Lower Franconia, southern Germany; their chronostratigraphic assumptions have relied mainly on German (pedo)stratigraphic schemes. In this study, we provide for the first time a chronology for LPSs in Lower Franconia based on optically stimulated luminescence (OSL) dating using quartz and a comparison of K-feldspar (63–100 µm) and the polymineral fraction (4–11 µm). Our results show that all obtained ages are in stratigraphic order, ranging from Holocene to late Pleistocene, and in general confirm the former stratigraphical interpretations. A good agreement of the obtained ages is observed between both feldspar grain size fractions; they also agree well with the quartz OSL ages up to ∼50 ka. However, a marked difference between the growth pattern of the dose response curves and consequently different saturation characteristics of fine and coarse grains is found. Even though in our samples the discrepancy in ages is not very significant, we suggest the use of coarse-grained K-feldspar whenever possible in order to not be confronted with unknowns such as the mineral composition of the polymineral fraction.

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44

Steadman, David W., Thomas W. Stafford e Robert E. Funk. "Nonassociation of Paleoindians with AMS-Dated Late Pleistocene Mammals from the Dutchess Quarry Caves, New York". Quaternary Research 47, n. 1 (gennaio 1997): 105–16. http://dx.doi.org/10.1006/qres.1996.1860.

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AbstractAMS14C ages of 10 bones of the caribou (Rangifer tarandus), flat-headed peccary (Platygonus compressus), and giant beaver (Castoroides ohioensis) from the Dutchess Quarry Caves, New York, range from 13,840 ± 80 to 11,670 ± 70 yr B.P. No bones from any of these species are demonstrably associated with Paleoindian artifacts (fluted points) or other cultural materials from the sites because the bones lack unequivocal stratigraphic association with artifacts, as well as physical (taphonomic) evidence for human association (e.g., burning, cut marks, distinctive breakage). Together with the Holocene conventional14C dates of charcoal and the varied stratigraphic proveniences of the fluted points and the dated bones, the new AMS14C dates argue that most strata at the Dutchess Quarry Caves contain a mixture of late Pleistocene and Holocene materials. This mixing probably resulted from post-depositional bioturbation (by humans, rodents, carnivores, and scavengers) and cryoturbation (annual freeze–thaw cycles). Rather than being of cultural origin, the bones of caribou, flat-headed peccary, and giant beaver likely were deposited in the Dutchess Quarry Caves by nonhuman predators or scavengers, such as ursids, canids, felids, condors, or eagles.

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45

Davies, Caroline Pickens. "Holocene Paleoclimates of Southern Arabia from Lacustrine Deposits of the Dhamar Highlands, Yemen". Quaternary Research 66, n. 3 (novembre 2006): 454–64. http://dx.doi.org/10.1016/j.yqres.2006.05.007.

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AbstractThis paper presents new evidence from the Dhamar highlands, Yemen, of paleohydrologic response to fluctuations in Holocene climate. Stratigraphic, geochemical, and chronological analyses of highland peat and lacustrine deposits contribute to knowledge of the timing of early Holocene moisture changes on the Arabian Peninsula, providing a backdrop to understanding early cultural development in the Arabian highlands. The location of the Dhamar highlands, characterized by intermontane valleys surrounded by the highest mountains on the Arabian Peninsula and adjacent to the Indian Ocean is ideal for examining the influence of the Indian Ocean Monsoon (IOM) on the moisture history of this region. Fluctuations in the lacustrine and paleosol records of the Dhamar highlands reflect both local changes in paleohydrology and regional influences on the Holocene paleoclimatic conditions in southwest Arabia. In addition, a peat deposit with a radiocarbon age of 10,253 ± 10,560 cal yr BP documents some of the earliest Holocene high moisture conditions on the Arabian Peninsula.

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46

Kolobova, K. A., A. V. Kharevich, A. S. Kolyasnikova, N. Ya Berezina e V. M. Kharevich. "Chagyrskaya Cave Middle Paleolithic Complexes Studies in the 2021 Field Season". Problems of Archaeology, Ethnography, Anthropology of Siberia and Neighboring Territories 27 (2021): 142–47. http://dx.doi.org/10.17746/2658-6193.2021.27.0142-0147.

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Abstract (sommario):

The article presents the results of field studies of the Chagyrskaya Cave, a key site of the Sibiryachikha facies of the Altai Middle Paleolithic in 2021. In the 2021 field season, the main objectives of the work were to study the site stratigraphy, determine the contribution of predators and humans to the taphocenoses of osteological remains, and techno-typological analysis of archaeological materials from the Middle Paleolithic complexes of the cave. Geological studies have shown that the stratigraphic sequences contain seven major subdivisions of the Holocene and Pleistocene periods. In the course of the excavations, a specific section of layer 6c/2 was determined; its non-disturbed position was supported by the stratigraphic and micromorphological data. The complex of the Neanderthal material culture in layer 6c/2 represents the remains of the Neanderthal base camp for hunting prey consumption. On the other hand, layer 6a was formed as a result of colluvial processes; the artifacts and paleontological remains from layer 6c/2 were redeposited in the overlying stratigraphic unit. Functionally, this layer is defined as a den of hyenas, which used the cave for cub breeding. This conclusion is supported by the shares of bones with traces of acid corrosion determined for the complexes of layers 6a and 6c/2 in 2021. In the course of fieldwork new retouchers were found supplementing the collection of bone artifacts of the Chagyrskaya cave. The discovery of an anthropological fossil indicates the prospect of continuing archaeological studies at the site.

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47

Huckell, Bruce B., e C. Vance Haynes. "The Ventana Complex: New Dates and New Ideas on Its Place in Early Holocene Western Prehistory". American Antiquity 68, n. 2 (aprile 2003): 353–71. http://dx.doi.org/10.2307/3557084.

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Radiocarbon dating of charcoal samples and a re-examination of the artifacts from the Volcanic Debris layer in Ventana Cave were conducted in 1992-1994. The goal of this research was to better understand the chronological position and cultural affinities of the Ventana Complex, the name applied to the assemblage recovered from the Volcanic Debris. Ten new Accelerator Mass Spectrometry (AMS) 14C ages suggest that the Volcanic Debris accumulated between approximately 8800 B.P. and 10,500 B.P., and the lack of stratigraphic ordering of the dates indicates that the Volcanic Debris was subjected to considerable turbation as it accumulated. This turbation may have led to the incorporation of bones of extinct fauna from an underlying conglomerate deposit rich in horse remains, creating the impression of their association with artifacts. The artifacts are probably the product of episodic, special-purpose occupations spanning centuries or millennia. Technological and morphological studies of the stone tools indicate few similarities with classic Paleoindian industries, and greater similarities to early Holocene Archaic occupations in the Great Basin and Southwest. Correlations of the Ventana Cave stratigraphy with that of southeastern Arizona and with the late Pleistocene and Holocene record of Northern Hemisphere climate are explored.

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Fuhrmann, Florian, Benedikt Diensberg, Xun Gong, Gerrit Lohmann e Frank Sirocko. "Aridity synthesis for eight selected key regions of the global climate system during the last 60 000 years". Climate of the Past 16, n. 6 (16 novembre 2020): 2221–38. http://dx.doi.org/10.5194/cp-16-2221-2020.

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Abstract. A compilation of the published literature on dust content in terrestrial and marine sediment cores was synchronized with pollen data and speleothem growth phases on the Greenland Ice Core Chronology 2005 (GICC05) time axis. Aridity patterns for eight key areas of the global climate system have been reconstructed for the last 60 000 years. These records have different time resolutions and different dating methods, i.e. different types of stratigraphy. Nevertheless, all regions analysed in this study show humid conditions during early Marine Isotope Stage 3 (MIS3) and the early Holocene or deglaciation, but not always at the same time. Such discrepancies have been interpreted as regional effects, although stratigraphic uncertainties may affect some of the proposed interpretations. In comparison, most of the MIS2 interval becomes arid in all of the Northern Hemisphere records, but the peak arid conditions of the Last Glacial Maximum (LGM) and Heinrich event 1 differ in duration and intensity among regions. In addition, we also compare the aridity synthesis with modelling results using a global climate model (GCM). Indeed, geological archives and GCMs show agreement on the aridity pattern for the Holocene or deglaciation, for the LGM and for late MIS3.

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Zernitskaya, V. P., e B. P. Vlasov. "Reflection of climate events in deposits of Belarusian Lakes at the Middle-Late Holocene transition". Limnology and Freshwater Biology, n. 4 (2022): 1625–27. http://dx.doi.org/10.31951/2658-3518-2022-a-4-1625.

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Abstract. The analysis of the proxy archives from lake sediments made it possible to install the natural indicators the Holocene into three stages at 8200 and 4200 cal. yr. BP, the timing is consistent with that seen in the Greenland ice-core data. We studied proxy archives based on pollen-stratigraphic, sedimentological, radiocarbon and isotopic dates.

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Allison, M. A., S. R. Khan, S. L. Goodbred e S. A. Kuehl. "Stratigraphic evolution of the late Holocene Ganges–Brahmaputra lower delta plain". Sedimentary Geology 155, n. 3-4 (febbraio 2003): 317–42. http://dx.doi.org/10.1016/s0037-0738(02)00185-9.

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