TY  - JOUR
A1  - Treat, Claire C.
A1  - Kleinen, Thomas
A1  - Broothaerts, Nils
A1  - Dalton, April S.
A1  - Dommain, Rene
A1  - Douglas, Thomas A.
A1  - Drexler, Judith Z.
A1  - Finkelstein, Sarah A.
A1  - Grosse, Guido
A1  - Hope, Geoffrey
A1  - Hutchings, Jack
A1  - Jones, Miriam C.
A1  - Kuhry, Peter
A1  - Lacourse, Terri
A1  - Lahteenoja, Outi
A1  - Loisel, Julie
A1  - Notebaert, Bastiaan
A1  - Payne, Richard J.
A1  - Peteet, Dorothy M.
A1  - Sannel, A. Britta K.
A1  - Stelling, Jonathan M.
A1  - Strauss, Jens
A1  - Swindles, Graeme T.
A1  - Talbot, Julie
A1  - Tarnocai, Charles
A1  - Verstraeten, Gert
A1  - Williams, Christopher J.
A1  - Xia, Zhengyu
A1  - Yu, Zicheng
A1  - Valiranta, Minna
A1  - Hattestrand, Martina
A1  - Alexanderson, Helena
A1  - Brovkin, Victor
T1  - Widespread global peatland establishment and persistence over the last 130,000 y
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - Glacial-interglacial variations in CO2 and methane in polar ice cores have been attributed, in part, to changes in global wetland extent, but the wetland distribution before the Last Glacial Maximum (LGM, 21 ka to 18 ka) remains virtually unknown. We present a study of global peatland extent and carbon (C) stocks through the last glacial cycle (130 ka to present) using a newly compiled database of 1,063 detailed stratigraphic records of peat deposits buried by mineral sediments, as well as a global peatland model. Quantitative agreement between modeling and observations shows extensive peat accumulation before the LGM in northern latitudes (> 40 degrees N), particularly during warmer periods including the last interglacial (130 ka to 116 ka, MIS 5e) and the interstadial (57 ka to 29 ka, MIS 3). During cooling periods of glacial advance and permafrost formation, the burial of northern peatlands by glaciers and mineral sediments decreased active peatland extent, thickness, and modeled C stocks by 70 to 90% from warmer times. Tropical peatland extent and C stocks show little temporal variation throughout the study period. While the increased burial of northern peats was correlated with cooling periods, the burial of tropical peat was predominately driven by changes in sea level and regional hydrology. Peat burial by mineral sediments represents a mechanism for long-term terrestrial C storage in the Earth system. These results show that northern peatlands accumulate significant C stocks during warmer times, indicating their potential for C sequestration during the warming Anthropocene.
KW  - peatlands
KW  - carbon
KW  - methane
KW  - carbon burial
KW  - Quaternary
Y1  - 2019
U6  - https://doi.org/10.1073/pnas.1813305116
SN  - 0027-8424
VL  - 116
IS  - 11
SP  - 4822
EP  - 4827
PB  - National Acad. of Sciences
CY  - Washington
ER  - 
TY  - JOUR
A1  - Panek, Tomas
A1  - Korup, Oliver
A1  - Lenart, Jan
A1  - Hradecky, Jan
A1  - Brezny, Michal
T1  - Giant landslides in the foreland of the Patagonian Ice Sheet
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Quaternary glaciations have repeatedly shaped large tracts of the Andean foreland. Its spectacular large glacial lakes, staircases of moraine ridges, and extensive outwash plains have inspired generations of scientists to reconstruct the processes, magnitude, and timing of ice build-up and decay at the mountain front. Surprisingly few of these studies noticed many dozens of giant (≥108 m3) mass-wasting deposits in the foreland. We report some of the world's largest terrestrial landslides in the eastern piedmont of the Patagonian Ice Sheet (PIS) along the traces of the former Lago Buenos Aires and Lago Puyerredón glacier lobes and lakes. More than 283 large rotational slides and lateral spreads followed by debris slides, earthflows, rotational and translational rockslides, complex slides and few large rock avalanches detached some 164 ± 56 km3 of material from the slopes of volcanic mesetas, lake-bounding moraines, and river-gorge walls. Many of these landslide deposits intersect with well-dated moraine ridges or former glacial-lake shorelines, and offer opportunities for relative dating of slope failure. We estimate that >60% of the landslide volume (∼96 km3) detached after the Last Glacial Maximum (LGM). Giant slope failures cross-cutting shorelines of a large Late Glacial to Early Holocene lake (“glacial lake PIS”) likely occurred during successive lake-level drop between ∼11.5 and 8 ka, and some of them are the largest hitherto documented landslides in moraines. We conclude that 1) large portions of terminal moraines can fail catastrophically several thousand years after emplacement; 2) slopes formed by weak bedrock or unconsolidated glacial deposits bordering glacial lakes can release extremely large landslides; and 3) landslides still occur in the piedmont, particularly along postglacial gorges cut in response to falling lake levels.
KW  - Quaternary
KW  - Landslide
KW  - Geomorphology
KW  - Relative dating
KW  - Glacier foreland
KW  - Glacial lake
KW  - Patagonian Ice Sheet
KW  - Paleogeography
KW  - South America
Y1  - 2018
U6  - https://doi.org/10.1016/j.quascirev.2018.06.028
SN  - 0277-3791
VL  - 194
SP  - 39
EP  - 54
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Owen, Richard Bernhart
A1  - Muiruri, Veronica M.
A1  - Lowenstein, Tim K.
A1  - Renaut, Robin W.
A1  - Rabideaux, Nathan
A1  - Luo, Shangde
A1  - Deino, Alan L.
A1  - Sier, Mark J.
A1  - Dupont-Nivet, Guillaume
A1  - McNulty, Emma P.
A1  - Leet, Kennie
A1  - Cohen, Andrew
A1  - Campisano, Christopher
A1  - Deocampo, Daniel
A1  - Shen, Chuan-Chou
A1  - Billingsley, Anne
A1  - Mbuthia, Anthony
T1  - Progressive aridification in East Africa over the last half million years and implications for human evolution
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - Evidence for Quaternary climate change in East Africa has been derived from outcrops on land and lake cores and from marine dust, leaf wax, and pollen records. These data have previously been used to evaluate the impact of climate change on hominin evolution, but correlations have proved to be difficult, given poor data continuity and the great distances between marine cores and terrestrial basins where fossil evidence is located. Here, we present continental coring evidence for progressive aridification since about 575 thousand years before present (ka), based on Lake Magadi (Kenya) sediments. This long-term drying trend was interrupted by many wet-dry cycles, with the greatest variability developing during times of high eccentricity-modulated precession. Intense aridification apparent in the Magadi record took place between 525 and 400 ka, with relatively persistent arid conditions after 350 ka and through to the present. Arid conditions in the Magadi Basin coincide with the Mid-Brunhes Event and overlap with mammalian extinctions in the South Kenya Rift between 500 and 400 ka. The 525 to 400 ka arid phase developed in the South Kenya Rift between the period when the last Acheulean tools are reported (at about 500 ka) and before the appearance of Middle Stone Age artifacts (by about 320 ka). Our data suggest that increasing Middle- to Late-Pleistocene aridification and environmental variability may have been drivers in the physical and cultural evolution of Homo sapiens in East Africa.
KW  - Quaternary
KW  - paleoclimate
KW  - paleolimnology
KW  - hominins
KW  - Lake Magadi
Y1  - 2018
U6  - https://doi.org/10.1073/pnas.1801357115
SN  - 0027-8424
SN  - 1091-6490
VL  - 115
IS  - 44
SP  - 11174
EP  - 11179
PB  - National Academy of Sciences
CY  - Washington
ER  - 
TY  - JOUR
A1  - Naafs, B. David A.
A1  - Hefter, Jens
A1  - Acton, Gary
A1  - Haug, Gerald H.
A1  - Martinez-Garcia, Alfredo
A1  - Pancost, Richard
A1  - Stein, Rüdiger
T1  - Strengthening of North American dust sources during the late Pliocene (2.7 Ma)
JF  - Earth & planetary science letters
N2  - Here we present orbitally-resolved records of terrestrial higher plant leaf wax input to the North Atlantic over the last 3.5 Ma, based on the accumulation of long-chain n-alkanes and n-alkanl-1-ols at IODP Site U1313. These lipids are a major component of dust, even in remote ocean areas, and have a predominantly aeolian origin in distal marine sediments. Our results demonstrate that around 2.7 million years ago (Ma), coinciding with the intensification of the Northern Hemisphere glaciation (NHG), the aeolian input of terrestrial material to the North Atlantic increased drastically. Since then, during every glacial the aeolian input of higher plant material was up to 30 times higher than during interglacials. The close correspondence between aeolian input to the North Atlantic and other dust records indicates a globally uniform response of dust sources to Quaternary climate variability, although the amplitude of variation differs among areas. We argue that the increased aeolian input at Site U1313 during glacials is predominantly related to the episodic appearance of continental ice sheets in North America and the associated strengthening of glaciogenic dust sources. Evolutional spectral analyses of the n-alkane records were therefore used to determine the dominant astronomical forcing in North American ice sheet advances. These results demonstrate that during the early Pleistocene North American ice sheet dynamics responded predominantly to variations in obliquity (41 ka), which argues against previous suggestions of precession-related variations in Northern Hemisphere ice sheets during the early Pleistocene.
KW  - aeolian input
KW  - dust
KW  - terrestrial higher plant waxes
KW  - Milankovitch
KW  - North Atlantic
KW  - Quaternary
Y1  - 2012
U6  - https://doi.org/10.1016/j.epsl.2011.11.026
SN  - 0012-821X
SN  - 1385-013X
VL  - 317
SP  - 8
EP  - 19
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Iryu, Yasufumi
A1  - Matsuda, Hiroki
A1  - Machiyama, Hideaki
A1  - Piller, Werner E.
A1  - Quinn, Terrence M.
A1  - Mutti, Maria
T1  - Introductory perspective on the COREF project
JF  - The island arc : official journal of the Geological Society of Japan
N2  - Coral reefs are tropic to subtropic, coastal ecosystems comprising very diverse organisms. Late Quaternary reef deposits are fossil archives of environmental, tectonic and eustatic variations that can be used to reconstruct the paleoclimatic and paleoceano-graphic history of the tropic surface oceans. Reefs located at the latitudinal limits of coral-reef ecosystems (i.e. those at coral-reef fronts) are particularly sensitive to environmental changes-especially those associated with glacial-interglacial changes in climate and sealevel. We propose a land and ocean scientific drilling campaign in the Ryukyu Islands (the Ryukyus) in the northwestern Pacific Ocean to investigate the dynamic response of the corals and coral-reef ecosystems in this region to Late Quaternary climate and sealevel change. Such a drilling campaign, which we call the COREF (coral-reef front) Project, will allow the following three major questions to be evaluated: (i) What are the nature, magnitude and driving mechanisms of coral-reef front migration in the Ryukyus? (ii) What is the ecosystem response of coral reefs in the Ryukyus to Quaternary climate changes? (iii) What is the role of coral reefs in the global carbon cycle? Subsidiary objectives include (i) the timing of coral-reef initiation in the Ryukyus and its causes; (ii) the position of the Kuroshio current during glacial periods and its effects on coral-reef formation; and (iii) early carbonate diagenetic responses as a function of compounded variations in climate, eustacy and depositional mineralogies (subtropic aragonitic to warm-temperate calcitic). The geographic, climatic and oceanographic settings of the Ryukyu Islands provide an ideal natural laboratory to address each of these research questions.
KW  - coral
KW  - Integrated Ocean Drilling Program
KW  - International Continental Scientific Drilling Program
KW  - limestone
KW  - Quaternary
KW  - reef
KW  - Ryukyu Group
KW  - Ryukyu Islands
KW  - sealevel
Y1  - 2006
U6  - https://doi.org/10.1111/j.1440-1738.2006.00537.x
SN  - 1038-4871
VL  - 15
IS  - 4
SP  - 393
EP  - 406
PB  - Wiley-Blackwell
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Engels, Stefan
A1  - Medeiros, Andrew S.
A1  - Axford, Yarrow
A1  - Brooks, Steve
A1  - Heiri, Oliver
A1  - Luoto, Tomi P.
A1  - Nazarova, Larisa B.
A1  - Porinchu, David F.
A1  - Quinlan, Roberto
A1  - Self, Angela E.
T1  - Temperature change as a driver of spatial patterns and long-term trends in chironomid (Insecta: Diptera) diversity
JF  - Global change biology
N2  - Anthropogenic activities have led to a global decline in biodiversity, and monitoring studies indicate that both insect communities and wetland ecosystems are particularly affected. However, there is a need for long-term data (over centennial or millennial timescales) to better understand natural community dynamics and the processes that govern the observed trends. Chironomids (Insecta: Diptera: Chironomidae) are often the most abundant insects in lake ecosystems, sensitive to environmental change, and, because their larval exoskeleton head capsules preserve well in lake sediments, they provide a unique record of insect community dynamics through time. Here, we provide the results of a metadata analysis of chironomid diversity across a range of spatial and temporal scales. First, we analyse spatial trends in chironomid diversity using Northern Hemispheric data sets overall consisting of 837 lakes. Our results indicate that in most of our data sets, summer temperature (T-jul) is strongly associated with spatial trends in modern-day chironomid diversity. We observe a strong increase in chironomid alpha diversity with increasing T-jul in regions with present-day T-jul between 2.5 and 14 degrees C. In some areas with T-jul > 14 degrees C, chironomid diversity stabilizes or declines. Second, we demonstrate that the direction and amplitude of change in alpha diversity in a compilation of subfossil chironomid records spanning the last glacial-interglacial transition (similar to 15,000-11,000 years ago) are similar to those observed in our modern data. A compilation of Holocene records shows that during phases when the amplitude of temperature change was small, site-specific factors had a greater influence on the chironomid fauna obscuring the chironomid diversity-temperature relationship. Our results imply expected overall chironomid diversity increases in colder regions such as the Arctic under sustained global warming, but with complex and not necessarily predictable responses for individual sites.
KW  - Arctic
KW  - biodiversity
KW  - climate warming
KW  - freshwater ecosystems
KW  - insects
KW  - palaeoecology
KW  - Quaternary
Y1  - 2019
U6  - https://doi.org/10.1111/gcb.14862
SN  - 1354-1013
SN  - 1365-2486
VL  - 26
IS  - 3
SP  - 1155
EP  - 1169
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Diaz, Nathalie
A1  - Dietrich, Fabienne
A1  - Sebag, David
A1  - King, Georgina E.
A1  - Valla, Pierre G.
A1  - Durand, Alain
A1  - Garcin, Yannick
A1  - de Saulie, Geoffroy
A1  - Deschamps, Pierre
A1  - Herman, Frederic
A1  - Verrecchia, Eric P.
T1  - Pedo-sedimentary constituents as paleoenvironmental proxies in the Sudano-Sahelian belt during the Late Quaternary (southwestern Chad Basin)
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Climate and environmental changes since the Last Glacial Maximum in the tropical zone of West Africa are usually inferred from marine and continental records. In this study, the potential of carbonate pedo-sedimentary geosystems, i.e. Vertisol relics, to record paleoenvironmental changes in the southwestern part of Chad Basin are investigated. A multi-dating approach was applied on different pedogenic organo-mineral constituents. Optically stimulated luminescence (OSL) dating was performed on the soil K-rich feldspars and was combined with radiocarbon dating on both the inorganic (C-14(inorg)) and organic carbon (C-14(org)) soil fractions. Three main pedo-sedimentary processes were assessed over the last 20 ka BP: 1) the soil parent material deposition, from 18 ka to 12 ka BP (OSL), 2) the soil organic matter integration, from 11 cal ka to 8 cal ka BP (C-14(org)), and 3) the pedogenic carbonate nodule precipitation, from 7 cal ka to 5 cal ka BP (C-14(inorg)). These processes correlate well with the Chad Basin stratigraphy and West African records and are shown to be related to significant changes in the soil water balance responding to the evolution of continental hydrology during the Late Quaternary. The last phase affecting the Vertisol relics is the increase of erosion, which is hypothesized to be due to a decrease of the vegetation cover triggered by (i) the onset of drier conditions, possibly strengthened by (ii) anthropogenic pressure. Archaeological data from Far North Cameroon and northern Nigeria, as well as sedimentation times in Lake Tilla (northeastern Nigeria), were used to test these relationships. The increase of erosion is suggested to possibly occur between c. 3 cal ka and 1 cal ka BP. Finally, satellite images revealed similar geosystems all along the Sudano-Sahelian belt, and initial C-14(inorg) ages of the samples collected in four sites gave similar ages to those reported in this study. Consequently, the carbonate pedo-sedimentary geosystems are valuable continental paleoenvironmental archives and soil water balance proxies of the semiarid tropics of West Africa. (C) 2018 Elsevier Ltd. All rights reserved.
KW  - Pedogenic carbonate nodules
KW  - Vertisol genesis
KW  - Soil water balance
KW  - Optical methods
KW  - Radiogenic isotopes
KW  - Quaternary
KW  - Monsoon
KW  - Western Africa
Y1  - 2018
U6  - https://doi.org/10.1016/j.quascirev.2018.05.022
SN  - 0277-3791
VL  - 191
SP  - 348
EP  - 362
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Berndt, Christopher
A1  - Yildirim, Cengiz
A1  - Ciner, Attila
A1  - Strecker, Manfred
A1  - Ertunc, Gulgun
A1  - Sarikaya, M. Akif
A1  - Özcan, Orkan
A1  - Ozturk, Tugba
A1  - Kiyak, Nafiye Gunec
T1  - Quaternary uplift of the northern margin of the Central Anatolian Plateau
BT  - New OSL dates of fluvial and delta-terrace deposits of the Kizilirmak River, Black Sea coast, Turkey
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - We analysed the interplay between coastal uplift, sea level change in the Black Sea, and incision of the Kizilirmak River in northern Turkey. These processes have created multiple co-genetic fluvial and marine terrace sequences that serve as excellent strain markers to assess the ongoing evolution of the Pontide orogenic wedge and the growth of the northern margin of the Central Anatolian Plateau. We used high-resolution topographic data, OSL ages, and published information on past sea levels to analyse the spatiotemporal evolution of these terraces; we derived a regional uplift model for the northward advancing orogenic wedge that supports the notion of laterally variable uplift rates along the flanks of the Pontides. The best-fit uplift model defines a constant long-term uplift rate of 0.28 +/- 0.07 m/ka for the last 545 ka. This model explains the evolution of the terrace sequence in light of active tectonic processes and superposed cycles of climate-controlled sea-level change. Our new data reveal regional uplift characteristics that are comparable to the inner sectors of the Central Pontides; accordingly, the rate of uplift diminishes with increasing distance from the main strand of the restraining bend of the North Anatolian Fault Zone (NAFZ). This spatial relationship between the regional impact of the restraining bend of the NAFZ and uplift of the Pontide wedge thus suggests a strong link between the activity of the NAFZ, deformation and uplift in the Pontide orogenic wedge, and the sustained lateral growth of the Central Anatolian Plateau flank. (C) 2018 Elsevier Ltd. All rights reserved.
KW  - Quaternary
KW  - OSL dating
KW  - Black Sea
KW  - Pontides
KW  - North Anatolian Fault Zone
KW  - Orogenic wedge
KW  - Kizilirmak River
KW  - MIS
KW  - Turkey
Y1  - 2018
U6  - https://doi.org/10.1016/j.quascirev.2018.10.029
SN  - 0277-3791
VL  - 201
SP  - 446
EP  - 469
PB  - Elsevier
CY  - Oxford
ER  -