Quaternary Environmental Change Research Articles

Climatically driven Quaternary sedimentation in a passive margin tropical context: Insights into the geomorphological evolution of Northeastern Brazil

Unconsolidated regolith from fluvial and hillslope origin occurring along the eastern seaboard of the Northeastern Brazil passive margin has long been overlooked as viable proxy for Quaternary environmental changes, or simply dismissed and interpreted as sediments of older planation cycles, for example, Neogene sediments. This study applies geochemical and geochronological techniques to assess the degree of weathering, sediment provenance and time of residence in the landscape. The results shed light on the upper Quaternary geomorphological history of the Borborema Piedmont, with depositional units spanning the last 50,000 years, as a response to climatic inputs in sync with major Pleistocene events (e.g., Heinrich Event 1, 2, 3 and 5, Last Glacial Maximum) and Holocene events in the Northern Hemisphere (e.g., Holocene Climatic Optimum), and the morphotectonic rearrangement of stream channels base level along reactivated fault-line subordinated to the underlying Proterozoic structural framework.

Interpreting the mammal deposits of Cloggs Cave (SEAustralia),GunaiKurnaiAboriginal Country, through community‐led partnership research

AbstractPalaeontological animal bone deposits are rarely investigated through research partnerships where the local First Nations communities have a defining hand in both the research questions asked and the research processes. Here we report research undertaken through such a partnership approach at the iconic archaeological site of Cloggs Cave (GunaiKurnai Country, East Gippsland), in the southern foothills of SE Australia's Great Dividing Range.A new excavation was combined with detailed chronometric dating, high‐resolution 3D mapping and geomorphological studies. This allowed interpretation of a sequence of stratigraphic layers spanning from a lowermost excavated mixed layer dated to between 25,640 and 48,470 cal BP, to a dense set of uppermost, ash layers dated to between 1460 and 3360 cal BP. This long and well‐dated chronostratigraphic sequence enabled temporal trends in the abundant small mammal remains to be examined.The fossil assemblage consists of at least 31 taxa of mammals which change in proportions through time. Despite clear evidence that the Old Ancestors repeatedly carried vegetation into the cave to fuel cool fires (no visible vegetation grows in Cloggs Cave), we observed little to no evidence of cooking fires or calcined bone, suggesting that people had little involvement with the accumulation of the faunal remains. Small mammal bones were most likely deposited in the cave by large disc‐faced owls,Tyto novaehollandae(Masked Owl) orTyto tenebricosa(Sooty Owl).Despite being well dated and largely undisturbed, the Cloggs Cave assemblage does not appear to track known Late Quaternary environmental change. Instead, the complex geomorphology of the area fostered a vegetation mosaic that supported mammals with divergent habitat preferences. The faunal deposit suggests a local ancestral landscape characterised by a resilient mosaic of habitats that persisted over thousands of years, signalling that the Old Ancestors burned landscape fires to encourage and manage patches of different vegetation types and ages within and through periods of climate change.Read the freePlain Language Summaryfor this article on the Journal blog.

Quaternary Environmental Changes Shaped Mitochondrial DNA Diversity in the Large Japanese Wood Mouse Apodemus speciosus in Hokkaido, Japan

Quaternary environmental change provided opportunities for rapid population expansion; however, the process of building the population spatial structures remains poorly understood. In this study, we determined the mitochondrial cytochrome b and control region sequences of 43 individuals of the large Japanese wood mouse (Apodemus speciosus) from Hokkaido, northern Japan and analyzed these data along with those from 40 other individuals. Consistent with the findings of our previous study, we found that two rapid expansion events, after the last glacial maximum (LGM) and Marine Isotope Stage (MIS) 4, shaped population genetic pattern of A. speciosus in Hokkaido. In northeastern Hokkaido, several ancient lineages that originated during MIS 3 were detected, whereas central Hokkaido was dominated by haplotypes descended from a single lineage that survived the LGM, suggesting that the populations of western part of Hokkaido were newly formed by westward migration from eastern Hokkaido during the post-LGM warm period. Alternatively, as post-LGM vegetation recovery is thought to have occurred gradually from west to east in Hokkaido, population expansion started in the west and moved gradually to the east, resulting in eastward haplotype movement; thus, western and eastern Hokkaido may have served as the haplotype source and sink, respectively.

The Kula–Salihli UNESCO Geopark: Spectacular records of Quaternary volcanism, fluvial and landscape evolution and Quaternary environmental change

The Kula–Salihli UNESCO Geopark, western Turkey, is a tectonically and volcanically active region in which the most recent eruptions of basaltic lava, associated with scoria cone formation, were during the latest Pleistocene and the Holocene. Much older volcanism within the same volcanic province is also in evidence, with some of the older lavas capping mesa-style uplands, such that they have preserved underlying poorly consolidated sediments that would otherwise have been lost to erosion. Beneath these hill-capping lavas, above the Neogene sediments representing endorheic basin-fill, are the early gravels of the River Gediz system, forming narrowly separated terraces (separation by a few metres) thought to have been formed in response to the ~41 kyrs obliquity-driven climate cycles of the Early Pleistocene. The rarity of terrace preservation from this early part of the Quaternary makes this a very valuable part of the geopark, in which there is also evidence for the progressive incision into the landscape, and for periodic damming of the river system by lava eruptions, bringing about lacustrine phases that can be recognized from lake sediments and deltas that were built into the former lakes. The combination of volcanic and drainage evolutionary evidence has few if any parallels elsewhere. The geopark, which also contains sites of archaeological and historical importance, is managed sustainably in order to maximize its educational, economic, touristic and heritage value.

Genetic drift drives rapid speciation of an Arctic insular endemic shrew (Sorex pribilofensis).

Episodes of Quaternary environmental change shaped the genomes of extant species, influencing their response to contemporary environments, which are changing rapidly. Island endemics are among the most vulnerable to such change, accounting for a disproportionate number of recent extinctions. To prevent extinctions and conserve island biodiversity it is vital to combine knowledge of species' ecologies with their complex evolutionary histories. The Bering Sea has a history of cyclical island isolation and reconnection, coupled with modern rates of climate change that exceed global averages. The endangered Pribilof Island shrew (Sorex pribilofensis) is endemic to St. Paul Island, Alaska, which was isolated from mainland Beringia ~14,000 years ago by rising sea levels. Using ~11,000 single nucleotide polymorphisms, 17 microsatellites and mitochondrial sequence data, we test predictions about the evolutionary processes driving shrew speciation across Beringia. Our data show considerable differentiation of S. pribilofensis from mainland sibling species, relative to levels of divergence between mainland shrews. We also find a genome-wide loss of diversity and extremely low Ne for S. pribilofensis. We then show that intraspecific genetic diversity is significantly related to interspecific divergence, and that differentiation between S. pribilofensis and other Beringian shrews is highest across loci that are fixed in S. pribilofensis, indicating that strong drift has driven differentiation of this island species. Our findings show that drift as a consequence of Arctic climate cycling can rapidly reshape insular biodiversity. Arctic island species that lack genomic diversity and have evolved in response to past climate may have limited ability to respond to modern environmental changes.

‘The most remarkable man’: James Croll, Quaternary scientist

ABSTRACTThe year 2021 marked the bicentenary of the birth of James Croll (1821–1890), the self‐educated son of a crofter‐stonemason, whose life was characterised by a dizzying range of occupations and homes, poor health and financial concerns, and yet he became a pioneer of orbital dynamics and ice age climate change with an impressive record of publication. Drawing upon archival information and recently published observations, this paper explores selected aspects of Croll's biography, his scientific connections and controversies, and that area of his life relevant to Quaternary science. He was a 19th century polymath whose multifaceted contributions have been a catalyst for subsequent systems‐based climate science on the grand scale, including the foundations for the seminal work of Milutin Milankovitch on the rhythms of Quaternary environmental change.

Environmental paleomicrobiology: using DNA preserved in aquatic sediments to its full potential.

SummaryIn‐depth knowledge about spatial and temporal variation in microbial diversity and function is needed for a better understanding of ecological and evolutionary responses to global change. In particular, the study of microbial ancient DNA preserved in sediment archives from lakes and oceans can help us to evaluate the responses of aquatic microbes in the past and make predictions about future biodiversity change in those ecosystems. Recent advances in molecular genetic methods applied to the analysis of historically deposited DNA in sediments have not only allowed the taxonomic identification of past aquatic microbial communities but also enabled tracing their evolution and adaptation to episodic disturbances and gradual environmental change. Nevertheless, some challenges remain for scientists to take full advantage of the rapidly developing field of paleo‐genetics, including the limited ability to detect rare taxa and reconstruct complete genomes for evolutionary studies. Here, we provide a brief review of some of the recent advances in the field of environmental paleomicrobiology and discuss remaining challenges related to the application of molecular genetic methods to study microbial diversity, ecology, and evolution in sediment archives. We anticipate that, in the near future, environmental paleomicrobiology will shed new light on the processes of microbial genome evolution and microbial ecosystem responses to quaternary environmental changes at an unprecedented level of detail. This information can, for example, aid geological reconstructions of biogeochemical cycles and predict ecosystem responses to environmental perturbations, including in the context of human‐induced global changes.

Quaternary environmental changes in central Chukotka (NE Russia) inferred from the Lake El'gygytgyn pollen records

ABSTRACTThe 3.6‐Myr sedimentary record of Lake El'gygytgyn is crucial for understanding the response of the sensitive ecosystems in the Arctic to Quaternary climate variations at orbital timescales. In this study, we synthesize previously published pollen records and biome reconstructions and perform pollen diversity analysis of the deep‐drilling core ICDP 5011‐1 from Lake El'gygytgyn for periods during the Early Pleistocene (MIS 82 – MIS 79), Early–Middle Pleistocene (MIS 31 – MIS 18) and late Middle Pleistocene (MIS 7e – MIS 6f). The results indicate that the predominance of herb tundra in the regional vegetation was most characteristic during glacials/stadials. Interglacials, in contrast, can be distinguished by the expansion of shrub communities mainly composed of birch, alder and willow. The expansion of forest biomes in the region was influenced by peaks in obliquity values, which led to increases in daylight length, which was essential for plant growth in high latitudes. An apparent long‐term decreasing trend in the tree and shrub population, accompanied by a reduction in floristic richness, was induced by stepwise cooling and drying since the Mid‐Pleistocene Transition (MPT), which is linked to the modulation of extended global ice volume during the MPT via strong snow‐ and ice‐albedo feedback effects.

What is Area to physical and environmental geography?

What is <i>Area</i> to physical and environmental geography?

Miocene-Late Quaternary environmental changes and molluscs as proxies of MIS-1 transgression in the Tinto-Odiel estuary, SW Spain

Miocene-Late Quaternary environmental changes and molluscs as proxies of MIS-1 transgression in the Tinto-Odiel estuary, SW Spain

A multi-proxy record of environmental change through the last 53,000 years recorded in the sediments of Lake Kanono, Northland, New Zealand

ABSTRACTLake sediment archives from Southern Hemisphere mid-latitude regions provide invaluable records of late Quaternary environmental change. Here, changes in depositional environment over the past ca. 53,000 years were reconstructed using a range of physical, sedimentological, geochemical, and μ-XRF elemental proxy datasets analyzed from lake sediment cores obtained from Lake Kanono, Northland, New Zealand. The Lake Kanono stratigraphy displays a terrestrial peat environment (ca. 53,700–6,670 cal yr BP), followed by a trend of increased influx of detrital sediment during the Late Glacial–Interglacial Transition (LGIT) at ca. 14,000 cal yr BP with a peak from ca. 12,000 to 9,000 cal yr BP driven by increasingly dry conditions. The increase in sediment influx continued during the early to mid-Holocene, leading to dune reactivation which altered the catchment dynamics of the region, leading to the inception of a shallow lake basin at ca. 6,670 cal yr BP. The timing of the formation of this lake basin can be associated with changes in intensity of the Southern Westerly Winds (SWW) and the appearance and increase in intensity of the El Niño Southern Oscillation (ENSO) after ca. 7,500–7,000 cal yr BP (Moy et al. 2002; Moreno et al. 2018). Drier conditions peaked from ca. 4,000 to 2,400 cal yr BP, possibly culminating in decreased lake levels that persisted from ca. 2,400 to 2,210 cal yr BP, renewed dune accumulation, and blocked stream outlets, resulting in a deep lake basin with thermal stratification that persisted to the present. Cluster analysis of the μ-XRF data demonstrates that the most prominent change in chemistry is near the onset of the Last Glacial Maximum (LGM) at ca. 26,700 cal yr BP associated with a transition to a drier, windier climate. The second most prominent change in the μ-XRF data is during the Polynesian phase of human settlement at ca. 612–575 cal yr BP (1338– 1375 CE). Hence, we can demonstrate the utility and power of a multi-proxy approach coupled with μ-XRF element data to interpret changing sediment sources to a lake basin. Such an approach allows rapid and reliable evaluation of catchment processes influenced by climate events and land-use changes at a resolution not available using other approaches.

Quaternary environmental changes in tropical Lake Towuti, Indonesia, inferred from end‐member modelling of X‐ray fluorescence core‐scanning data

ABSTRACTContinental and marine sediments are composed of a mixture from different sources and are influenced by a variety of environmental factors and transport processes prior to deposition. For analysis and interpretation, these sources and processes are often challenging to disentangle. We show that end‐member modelling of X‐ray fluorescence (XRF) core‐scanning data helps to overcome these challenges by unmixing different environmental signals from high‐resolution sediment geochemical records. We apply this approach to a 100 m long lacustrine succession from Lake Towuti, Indonesia, to separate the regional climate and tectonic history from local ecological and diagenetic processes. The resulting six end‐members (EMs) are interpreted to represent changes in ecological (EM1), climatic (EMs 2–4), tectonic (EM 5) and geomorphic (EM6) processes determining changes in sediment composition. Because end‐member analysis allows for the tracking of transient and overlapping processes, climatic changes can be followed throughout the 100 m‐long succession, suggesting alternating wet and dry periods in Central Sulawesi over long (several 100 000 years) time scales. We show that end‐member analysis on elemental data sets offers a detailed and objective means to disentangle depositional processes in sedimentary successions resulting from varying tectonic and environmental factors involved in sediment formation and deposition.

Lyell, the Geikies and Croll's observations on terrestrial glacial sediments and landforms

ABSTRACTWithin the context of the work and achievements of James Croll, this paper reviews the records of direct observations of glacial landforms and sediments made by Charles Lyell, Archibald and James Geikie and James Croll himself, in order to evaluate their contributions to the sciences of glacial geology and Quaternary environmental change. The paper outlines the social and physical environment of Croll's youth and contrasts this with the status and experiences of Lyell and the Geikies. It also outlines the character and role of the ‘Glasgow School’ of geologists, who stimulated Croll's interest into the causes of climate change and directed his focus to the glacial and ‘interglacial’ deposits of central Scotland. Contributions are outlined in chronological order, drawing attention to: (i) Lyell's high-quality observations and interpretations of glacial features in Glen Clova and Strathmore and his subsequent rejection of the glacial theory in favour of processes attributed to floating icebergs; (ii) the significant impact of Archibald Geikie's 1863 paper on the ‘glacial drift of Scotland’, which firmly established the land-ice theory; (iii) the fact that, despite James Croll's inherent dislike of geology and fieldwork, he provided high-quality descriptions and interpretations of the landforms and sediments of central Scotland in order to test his theory of climate change; and (iv) the great communication skills of James Geikie, enhanced by contacts and evidence from around the world. It is concluded that whilst direct observations of glacial landforms and sediments were critical to the long-term development of the study of glaciation, the acceptance of this theory was dependent also upon the skills, personality and status of the Geikies and Croll, who developed and promoted the concepts. Sadly, the subsequent rejection of the land-ice concept by Lyell resulted in the same factors challenging the acceptance of the glacial theory.

Late Quaternary environmental changes of Lake Urmia basin (NW Iran) inferred from sedimentological and magnetic records

The ongoing changes affecting Lake Urmia (NW Iran) are revealed by the lake water level decrease (~7 m in the last 20 yr) that was attributed to natural and anthropogenic causes but the exact impact of these factors on the state of the lake is still not identified. Indeed, lack of detailed record of environmental evolution of the lake in the past limits the understanding of actual and future processes. Our project aims to obtain a high-temporal resolution record of environmental changes in the lake area for the last ~30 kyrs. Sediment cores have been obtained from the recently dried out part of the lake near Urmia City, and surface and ground waters have been measured for electric conductivity. This paper presents results of water and sediments analyses. Six 14C AMS dating on organic fractions provide a chronological framework and indicate that the record covers the last ~30 cal kyr BP. During this period, evaporitic conditions were prevailing in the lake. The electric conductivity of brines from the sediment highlights changes in the lake water salinity. The data indicate a lake-level low stand at ~30 cal kyr BP that was followed by a water level rise and establishment of lacustrine conditions for the next ~9 kyr, this phase representing the highest lake level recorded since that time to date. From the LGM, the lake experienced several fluctuations of the water level. The relatively long-term lacustrine condition established during the Early Holocene before the water level decrease between ~5.5 and 4.9 cal kyr BP. Sediments from the two dry events at ~30 cal kyr BP and at 5.5–4.9 cal kyr BP are characterized by the presence of greigite, which indicates anaerobic early diagenetic conditions in the sediment.

Influence of Quaternary environmental changes on mole populations inferred from mitochondrial sequences and evolutionary rate estimation

Quaternary environmental changes fundamentally influenced the genetic diversity of temperate-zone terrestrial animals, including those in the Japanese Archipelago. The genetic diversity of present-day populations is taxon- and region-specific, but its determinants are poorly understood. Here, we analyzed cytochrome b gene (Cytb) sequences (1140 bp) of mitochondrial DNA (mtDNA) to elucidate the factors determining the genetic variation in three species of large moles: Mogera imaizumii and Mogera wogura, which occur in central and southern mainland Japan (Honshu, Shikoku, and Kyushu), and Mogera robusta, which occurs on the nearby Asian continent. Network construction with the Cytb sequences revealed 10 star-shaped clusters with apparent geographic affinity. Mismatch distribution analysis showed that modes of pairwise nucleotide differences (τ values) were grouped into five classes in terms of the level, implying the occurrence of five stages for rapid expansion. It is conceivable that severe cold periods and subsequent warm periods during the late Quaternary were responsible for the population expansion events. The first and third oldest events included island-derived haplotypes, indicative of the involvement of land bridge formation between remote islands, hence suggesting an association of the ends of the penultimate (PGM, ca. 130,000 years ago) and last (LGM, ca. 15,000 years ago) glacial maxima, respectively. Since the third event was followed by the fourth, it is plausible that the termination of the Younger Dryas and subsequent abrupt warming ca. 11,500 years ago facilitated the fourth expansion event. The second event most likely corresponded to early marine isotope stage (MIS) 3 (ca. 53,000 years ago) when the glaciation and subsequent warming period were predicted to have influenced biodiversity. Utilization of the critical times of 130,000, 53,000, 15,000, and 11,500 years ago as calibration points yielded evolutionary rates of 0.03, 0.045, 0.10 and 0.10 substitutions/site/million years, respectively, showing a time-dependent manner whose pattern was similar to that seen in small rodents reported in our previous studies. The age of the fifth expansion event was calculated to be 5800 years ago with a rate of 0.10 substitutions/site/million years ago during the mid-Holocene, suggestive of the influence of humans or other unspecified reasons, such as the Jomon marine transgression.

The time-dependent evolutionary rate of mitochondrial DNA in small mammals inferred from biogeographic calibration points with reference to the late Quaternary environmental changes in the Japanese archipelago

The time-dependent evolutionary rate of mitochondrial DNA in small mammals inferred from biogeographic calibration points with reference to the late Quaternary environmental changes in the Japanese archipelago

Bird populations and species lost to Late Quaternary environmental change and human impact in the Bahamas

Comparing distributional information derived from fossils with the modern distribution of species, we summarize the changing bird communities of the Bahamian Archipelago across deep ecological time. While our entire dataset consists of 7,600+ identified fossils from 32 sites on 15 islands (recording 137 species of resident and migratory birds), we focus on the landbirds from four islands with the best fossil records, three from the Late Pleistocene (∼25 to 10 ka [1,000 y ago]) and one from the Holocene (∼10 to 0 ka). The Late Pleistocene sites feature 51 resident species that have lost one or more Bahamian populations; 29 of these species do not occur in any of the younger Holocene sites (or in the Bahamas today). Of these 29 species, 17 have their closest affinities to species now or formerly living in Cuba and/or North America. A set of 27 species of landbirds, most of them extant somewhere today, was more widespread in the Bahamas in the prehistoric Holocene (∼10 to 0.5 ka) than they are today; 16 of these 27 species were recorded as Pleistocene fossils as well. No single site adequately captures the entire landbird fauna of the combined focal islands. Information from all sites is required to assess changes in Bahamian biodiversity (including endemism) since the Late Pleistocene. The Bahamian islands are smaller, flatter, lower, and more biotically depauperate than the Greater Antilles, resulting in more vulnerable bird communities.

GIS and DEM based analysis of incision and drainage reorganization of the Buyuan River basin in the upper Lancang-Mekong of China since the Late Pleistocene

River incision and drainage reorganization have an important impact on the site selection of many major projects including city, road and others, and are the key issues of Quaternary environmental changes. Studies of river incision and river-network adjustment have traditionally been based on extensive field evidence, such as sediment age and beheaded river system. The Buyuan River basin is a large sub-basin of the upper Lancang-Mekong, with high mountains and extremely active erosion. The latter affects the preservation of the Quaternary period sediments leading to difficulties in understanding the main evolution characteristics of the basin. This study investigates differences in the equilibrium state of the longitudinal profile, infers incision rates, and evaluates drainage divide migration timelines using the stream-power incision model, the latest morphological dating, and Chi-plots (χ-z) based on digital elevation models (DEMs) on the GIS software platform. The final results show that two significant erosion base-level decreases occurred in the Late Pleistocene at least. The incision rate of the mainstream might have been 0–2.99 mm/yr since 100 ka BP and 0–3.28 mm/yr since 46 ka BP. The Chi-values across the divides suggest that space limited (or constrained) river reorganization and that there is no severe reorganization in the basin; the imbalance of traceable erosion only exists in local areas. The main driving force for the geomorphologic evolution of the Buyuan River basin is likely climate fluctuations rather than strong tectonic uplift since the Late Pleistocene.

Sedimentary and foraminiferal records of Late Quaternary environmental change west of Ireland and implications for the last British–Irish Ice Sheet

ABSTRACTPalaeoenvironmental change following deglaciation of the last British–Irish Ice Sheet on the continental shelf west of Ireland was investigated using multiproxy analyses of sediment and foraminifera data from nine sediment cores. Lithofacies associations record various depositional regimes across the shelf, which evolve from subglacial to postglacial conditions. Census data provide the first characterisation of benthic foraminifera populations across the continental shelf and multivariate analyses reveal three distinct biotopes. Biomineralization within these biotopes is restricted to ≤21 200 cal a bp by four radiocarbon ages. The transition from glacial to postglacial benthic foraminifera populations near the shelf break marks the establishment of productive, nutrient‐rich, ice‐distal conditions at ~20 900 cal a bp; these conditions may also mark the start of favourable conditions for postglacial cold‐water coral growth. Postglacial conditions on the inner shelf were not established until &lt;14 500 cal a bp, suggesting glacial conditions west of Ireland may have persisted into the Bølling–Allerød Interstadial.

Dating of a late Quaternary loess section from the northern slope of the Tianshan Mountains (Xinjiang, China) and its paleoenvironmental significance

Late Quaternary loess deposits from the Tianshan Mountains are potentially valuable archives for the study of environmental change. However, the reported chronologies of the loess deposits in this area are still controversial. Previous studies have shown that there remain discrepancies between the optically stimulated luminescence (OSL) ages and accelerator mass spectrometry (AMS) 14C ages of the loess deposits from the Yili Valley. To establish a robust chronological sequence of the Shichengzi section (SCZ17) from the northern slope of the Tianshan Mountains in Xinjiang, we adopted both AMS14C and quartz OSL dating methods and the dates-based chronology was further refined by correlating sedimentary proxies (loss-on-ignition and grain size) with the proxy information from other sequences. Comparison of the AMS 14C and quartz OSL ages suggests that the AMS 14C ages of bulk organic matter are generally younger than the quartz OSL ages, with the maximum age discrepancy reaching up to ~10 ka. Regional correlation of the Holocene lithology of the SCZ17 section with other Holocene lithologies from the Tianshan Mountains reveals that the Holocene paleosol formation occurred in the late Holocene. The analyzed proxy data (e.g., grain size, carbonate content) indicate a cold and dry climate from 21.6 to ~10 ka, and a persistent wetting trend during the past ~10 ka. This study provided interesting and new evidence of late Quaternary environmental changes in arid central Asia.