Late Pleistocene Record Research Articles

Loess–paleosol carbonate clumped isotope record of late Pleistocene–Holocene climate change in the Palouse region, Washington State, USA

AbstractThe Channeled Scabland–Palouse region of the Pacific Northwest (PNW) of the United States preserves geomorphic and pedosedimentary records that inform understanding of late Pleistocene–Holocene paleoclimate change in a region proximal to the last glacial period Cordilleran Ice Sheet. We present a clumped (Δ47) and conventional (δ18O, δ13C) isotopic study of Palouse loess–paleosol carbonates in combination with carbonate radiocarbon (14C) dating to provide new measures of regional late–last glacial (~31–20 cal ka BP) and Holocene soil conditions. Average clumped isotope temperatures (T(Δ47)) for last glacial Palouse loess–paleosol carbonates (9±4°C) are significantly lower than those for Holocene-aged carbonates (T(Δ47)=18±2°C) in study sections. Calculated soil water δ18OVSMOWvalues (−16±2‰) for last glacial carbonates are also offset relative to those for Holocene-aged samples (−11±1‰), whereas calculated soil CO2δ13CVPDBvalues are similar for the Holocene (−16.9±0.2‰) and late–last glacial (−16.7±1.1‰) periods. Together, these paleoclimate metrics indicate late–last glacial conditions of pedogenic carbonate formation in the C3grassland soils of the Palouse were measurably colder (9±5°C) than during the Holocene and potentially reflect a more arid last glacial paleoclimate across the Palouse, findings in agreement with previous proxy studies and climate model simulations for the region.

Late Pleistocene (Rancholabrean) Mammalian Assemblage from Paw Paw Cove, Tilghman Island, Maryland

A small but significant assemblage of Late Pleistocene mammals was recovered from an eroding shoreline at Paw Paw Cove, located on the Chesapeake Bay side of Tilghman Island, Talbot County, Maryland. Additionally, Clovis-age (11,050–10,800 radiocarbon [14C] years before present) artifacts were found in a lag deposit beneath a loess deposit at the site. An accelerator mass spectrometry date obtained from an organic stratum below the loess at the same location suggests that this small fossil assemblage is approximately 21,000 years old. Identifiable taxa include four extinct species, Castoroides sp. (giant beaver), Equus sp. (horse), Tapirus veroensis (Vero tapir), and Mammut americanum (American mastodon), along with Canis cf. C. latrans (coyote), and Cervus elaphus (wapiti). Significantly, the tapir and giant beaver are the first records for Maryland, and the tapir is the first record from the Coastal Plain of the Chesapeake region of Delaware, Maryland, and Virginia. The provisional identification of Canis cf. C. latrans may represent the first Late Pleistocene record from the Coastal Plain of the Chesapeake region of Delaware, Maryland, and Virginia.

On the origin of modern humans: Asian perspectives.

The traditional "out of Africa" model, which posits a dispersal of modern Homo sapiens across Eurasia as a single wave at ~60,000 years ago and the subsequent replacement of all indigenous populations, is in need of revision. Recent discoveries from archaeology, hominin paleontology, geochronology, genetics, and paleoenvironmental studies have contributed to a better understanding of the Late Pleistocene record in Asia. Important findings highlighted here include growing evidence for multiple dispersals predating 60,000 years ago in regions such as southern and eastern Asia. Modern humans moving into Asia met Neandertals, Denisovans, mid-Pleistocene Homo, and possibly H. floresiensis, with some degree of interbreeding occurring. These early human dispersals, which left at least some genetic traces in modern populations, indicate that later replacements were not wholesale.

OSTRACODE BIOFACIES AND SHELL CHEMISTRY REVEAL QUATERNARY AQUATIC TRANSITIONS IN THE POZUELOS BASIN (ARGENTINA)

Here we present the first use of calcareous microfossils to examine the late Quaternary paleoecology of the endorheic Pozuelos Basin (Argentina). Modern deposition in the basin centers on Laguna de los Pozuelos (LP), a shallow playa-lake that is fed by axial rivers and groundwater and dominantly accumulates siliciclastic sediments. Today, the distribution of limnocytherid and cypridoidean ostracodes across southern LP is strongly influenced by distance to the Rio Cincel delta, whereas the northern end of the playa-lake is characterized by a paucity of ostracodes due to frequent sub-aerial exposure. Ten ostracode biofacies define a sediment core retrieved from LP, which reveal progressive changes in aquatic environments that varied in salinity, depth, and proximity to deltas over the late Pleistocene. Closed lakes occupied the basin from ∼ 37.6–30.7 ka, ∼ 28.0–25.0 ka, and ∼ 23.0–16.6 ka, whereas saline wetlands occurred when these lakes contracted. Extant LP has no analog in the late Pleistocene record; it formed after ∼ 7.2 ka, following a hiatus that removed the Pleistocene–Holocene transition. Paleoecological evidence indicates that the core site was influenced by deltaic inflows from the eastern basin margin until ∼ 24.3 ka, an area where today dry alluvial fans are found. Reorganization of the watershed by normal faulting, most likely at ∼ 18.0 ka, appears to have reduced the influence of these deltaic inflows. Extensional neotectonics, perhaps induced by incorporation of the Pozuelos Basin into the Andean hinterland, is a mechanism that along with tropical climate change is potentially important to water balance and ecology in high-altitude convergent orogenic basins.

Late Pliocene–Pleistocene record of the Garding-2 research drill core, Northwest Germany

Late Pliocene–Pleistocene record of the Garding-2 research drill core, Northwest Germany

A review of Quaternary proboscideans from Alberta, Canada

Here we present a summary of the largest museum collection of Quaternary proboscideans known from Alberta, housed at the Royal Alberta Museum. The 378 specimens reported here come from localities across the province, highlighting the broad distribution of proboscideans in southwestern Canada during the late Pleistocene. Despite the isolated nature of most individual specimen records, the cumulative record provides a broad sense of the chronologic distribution of late Pleistocene proboscideans in a large portion of southwestern Canada. New and summary radiocarbon data indicate that the sparse record of pre-LGM mastodon (Mammut americanum) is limited to >40,700 ± 3000 yr BP, suggesting a pattern of pre-LGM extirpation previously observed at more northern latitudes. Mammoths (Mammuthus spp.) occur in greater numbers and have a more lengthy late Pleistocene record, characterized by a temporal gap related to the Last Glacial Maximum (LGM).

Micromorphology of late Pleistocene and Holocene sediments and a new interpretation of the Holocene chronology at Anderson Pond, Tennessee, USA

AbstractThin-section (micromorphological) analysis of samples from the upper 1.5 m of a core obtained in 2007 from Anderson Pond, Tennessee, reveals a coherent but discontinuous record of late Pleistocene and Holocene climate change that supports some interpretations from previous pollen and charcoal analyses but indicates a revised Holocene chronology for this classic pollen site. Legacy sediments recording anthropogenic disturbance compose the upper 65 cm of the core (<160 cal yr BP) and are characterized by mixed, darker-colored, and coarser-grained deposits containing reworked soil aggregates, which sharply overlie finer-grained and lighter-colored, rooted middle Holocene sediments interpreted as a paleosol. These mid-Holocene sediments (95–65 cm; 7100–5600 cal yr BP) record extensive warm-dry subaerial soil conditions during the middle Holocene thermal maximum, manifested by illuviated clay lining root pores, and also contain abundant charcoal. Late Pleistocene sediments (150–95 cm), dark-colored and organic-rich, record open-water conditions and include siliceous aggregate grains at 143–116 cm (14,300–13,900 cal yr BP), recording intense fires. Thin sections are not commonly used in studies of paleoclimate from Quaternary lacustrine sediments, but we advocate for their inclusion in multianalytical approaches because they enhance resolution of depositional and pedogenic processes.

Paleoenvironmental change in the late Middle Pleistocene–Holocene Kibish Formation, southern Ethiopia: Evidence from ungulate isotopic ecology

East Africa has produced the earliest record of Homo sapiens~200ka and a punctuated record of Middle Stone Age and Later Stone Age behaviors. We lack, however, a detailed late Quaternary paleoenvironmental record for the region, particularly during humid periods. Without a regional record, hypotheses about the evolution and ecology of early Homo sapiens in East Africa remain vague and untestable. The Kibish Formation of southern Ethiopia presents a long, albeit punctuated, record of late Middle Pleistocene to Holocene faunal change in East Africa, which was deposited during humid periods. Here, we present oxygen and carbon stable isotope data of the Kibish ungulates and test whether there are environmental changes within the Kibish Formation. Significant differences in δ18O enamel isotopes are consistent with more humid conditions during the Holocene-age Member IV (~13–4ka) than either Pleistocene-age Member I (~196ka) or Member III (~104ka). Mesowear data document a shift toward more attritional wear among grazers in Member IV and are correlated with more depleted δ18O enamel values, suggesting that the wear pattern shift is linked to the onset of more humid conditions during the Holocene. δ13C enamel values show subtle variations through time, but do not suggest any major changes in diets. We propose that the paleoenvironmental differences evident in Member IV, based on δ18O enamel values, mesowear, and bovid abundances, may be explained by cooler and wetter conditions at the beginning of the Holocene in the lower Omo Valley. The evidence suggesting that the Holocene humid phase is more pronounced than earlier humid phases may explain why arid-adapted grassland ungulates became extinct in East Africa by the Pleistocene–Holocene transition, but persisted through previous humid phases of the late Quaternary.

At the Intersection of Geology, Archaeology, History, and Art: Engineer Cantonment (1819–1820), Washington County, Nebraska

In the fall of 1819, members of the Stephen Long Expedition constructed two log and limestone buildings along the west bank of the Missouri River north of modern Omaha, Nebraska, to serve as their winter quarters (Engineer Cantonment). A detailed watercolor and sketches of the site by expedition member Titian Ramsay Peale were key to the rediscovery of Engineer Cantonment. Subsequent excavations of the site identified three distinct archaeological components: two Native American hearths that date to the late Holocene, about 870 and 810 14 C years before present (BP), the Engineer Cantonment from AD 1819–20, and a farmstead from the late 19th to mid-20th century. The site is a low terrace-fan complex composed of four major depositional units: a late Holocene Missouri River alluvial fill, a late Holocene through modern alluvial fan, a younger historic alluvial fill, and 19th-to 20th-century Missouri River floodplain deposits. The late Holocene fill is a fining-upward sequence of channel sand and gravel overlain by silt and clay overbank deposits with redoximorphic features. The fan includes multiple beds of yellowish brown, brown, and gray alluvial fan sediments with thin, weakly developed buried soils. The historic alluvial fill truncates the distal portions of the alluvial fan and the upper portions of the late Holocene fill. The modern floodplain deposits consist of a thin bed of silty clay overlying cross-bedded silty sand. Our study demonstrates two things: the significance of the margins of the valley floor of the Missouri River as a record of late Pleistocene through modern fluvial activity, and a potentially long record of human occupation of the valley during the Holocene. This project also demonstrates the potential usefulness of 19th-century art in the study of cultural and environmental change during the last two centuries.

Supplementing a Tulare Lake, California late Pleistocene and Holocene Lake-level record using geochemical and geophysical proxies from core sediments; continuing work

Supplementing a Tulare Lake, California late Pleistocene and Holocene Lake-level record using geochemical and geophysical proxies from core sediments; continuing work

Cold-climate rodent indicators for the Late Pleistocene of Central Iberia: New data from the Buena Pinta Cave (Pinilla del Valle, Madrid Region, Spain)

In the Iberian Peninsula, the Late Pleistocene record of small mammal indicators of cold climates is largely restricted to two sets of sites at the eastern and western ends of the Pyrenees. Some assemblages from other sites at the Peninsular centre have, however, recently yielded such taxa. This work describes the remains of three such rodent species from the Buena Pinta Cave, a site in the Sierra de Guadarrama mountains in the Spanish Central System. Excavation campaigns in the cave have taken place every summer since 2003. Thermoluminescence analyses of sediments from levels 2–5 of the site suggest an age corresponding to the middle of the Late Pleistocene, within Marine Isotope Stage 4 or the beginning of Marine Isotope Stage 3. Sieve-washing and picking out of the small fossils contained in the sediments of levels 2–5 yielded several thousand small mammal teeth and other remains, dominated by Microtus arvalis. Smaller numbers of remains belonging to other rodents typical of cold climates were also identified, such as Microtus oeconomus, Microtus gregalis and Chionomys nivalis. Thus, the small mammal record of the Buena Pinta Cave shows that rodent indicators of cold climates reached the centre of the Iberian Peninsula during the mid-Late Pleistocene, i.e., well before the Last Glacial Maximum. These findings represent one of the southernmost Pleistocene records for M. oeconomus in Europe, and the most southerly for M. gregalis.

‘We have never been behaviourally modern’: The implications of Material Engagement Theory and Metaplasticity for understanding the Late Pleistocene record of human behaviour

The emergence of the human mind is a topic that has been of considerable interest to the disciplines of archaeology, cognitive archaeology and neuroscience in recent years. Most research in this regard has tended to focus on what material culture associated with early Homo sapiens might reflect in terms of the timing and nature of early cognitive capacities and ‘behavioural modernity’. In recent years, however, both the concept of ‘behavioural modernity’ and its passive treatment of material culture have become highly criticised. Yet, until now, there has remained some confusion as to where to turn in its absence. Recently, Lambros Malafouris outlined the theoretical frameworks of Material Engagement Theory and Metaplasticity as a means to understand the active role of material culture in the constitution of the human mind. However, despite Malafouris' application of these theoretical frameworks to a series of case studies previously associated with human cognitive ‘modernity’ (including tool manufacture, early body ornamentation, and ritual art), the Late Pleistocene archaeological community has done little to engage with this work. In this paper I outline and then apply MET and Metaplasticity to two further case studies often considered pertinent to the development of human cognition in the Late Pleistocene – namely, long-distance resource sourcing and/or exchange and the development of composite technologies. In doing so, I hope to demonstrate that there is somewhere to turn in the wake of the statement ‘we have never been behaviourally modern’.

Introducing an improved multi-proxy approach for paleoenvironmental reconstruction of loess–paleosol archives applied on the Late Pleistocene Nussloch sequence (SW Germany)

To study paleoenvironmental and paleoclimatic changes in loess–paleosol sequences (LPS), most proxies except for screening parameters have often been applied at low sampling density, typically 1–2 per stratigraphic unit. This might lead to results that overlook paleovegetation effects that were not only restricted to paleosols but also affected underlying loess material. Here, a new profile was investigated in the loess–paleosol sequence (LPS) at Nussloch, SW Germany using a high resolution multi-proxy approach to improve our understanding of the Late Pleistocene record which serves as a standard sequence in Central Europe. This approach included several geophysical and geochemical parameters, as well as frequencies of root-related features.Grain size distribution and OSL dating enabled correlation of the new section with the nearby standard profile P4, revealing considerable variations of the thickness of stratigraphic units due to local small-scale variations in depositional conditions and paleogeomorphology of longitudinal greda structures. Magnetic susceptibility revealed weathering of the entire LPS under more humid conditions than those described for SE European and Chinese LPS. It further enabled a rough differentiation between an interval that was influenced by pedogenic processes (Lower Pleniglacial to lower part of the Upper Pleniglacial), and loess that was not markedly affected by soil formation. Color measurements confirmed these results and enabled the identification of several paleosols in the Upper Pleniglacial. For the uppermost part of the LPS, low magnetic susceptibility and inorganic geochemical parameters such as low Fe/Ti ratios indicated only weak or no pedogenic influence. In contrast, considerable variations e.g. in carbonatic carbon contents and organic carbon/nitrogen (C/N) ratio might be related to the high frequency of calcified root remains (up to 200rhizolithsm−2 and up to 12,500microrhizolithsm−2) in certain depth intervals of the LPS, entailing incorporation and degradation of organic matter. Frequencies of biopores, which are suggested to derive largely from former root growth and, to a lesser extent, from insect and earthworm bioturbation, were related to paleosols, and thus confirmed the pedostratigraphy.An improved assessment of terrestrial sedimentary archives can be achieved by high-resolution multi-proxy analysis and three-dimensional investigation of terrestrial sediments that are prone to bioturbation.

A Late Pleistocene record of climate and environmental change from the northern and southern Kelabit Highlands of Sarawak, Malaysian Borneo

A late Pleistocene vegetation record is presented, using multi-proxy analysis from three palaeochannels in the northern (Bario) and southern (Pa'Dalih) Kelabit Highlands of Sarawak, Malaysian Borneo. Before 50 000 cal a BP and until ∼47 700 cal a BP [marine isotope stage 3 (MIS3)], two of the sites were probably being influenced by energetic fluvial deposition, possibly associated with strong seasonality. Fluvial activity declines between 47 700 and 30 000 cal a BP (MIS3), and may be associated with a reduction in seasonality with overall stability in precipitation. The pollen record between 47 700 and 30 000 cal a BP generally shows much higher representation of upper-montane taxa compared with the Holocene, indicating often significantly reduced temperatures. After 35 000–30 000 cal a BP and until the mid-Holocene, hiatuses appear in two of the records, which could be linked to fluvial down-cutting during the late/mid Holocene. Despite the jump in ages, a pronounced representation of Ericaceae and upper-montane taxa, represented both at Bario and at Pa'Dalih, corresponds to a further lowering of temperatures during the Last Glacial Maximum (MIS2). Thick charcoal bands in the PDH 210 record also suggest periods of extreme aridity between 30 200 and 12 700 cal a BP. This is followed by energetic fluvial deposition of sands and gravels, and may reflect a significant increase in seasonality.

Geochemical fingerprinting of Wilson Creek formation tephra layers (Mono Basin, California) using titanomagnetite compositions

Nineteen tephra layers within the Wilson Creek formation near Mono Lake provide a record of late Pleistocene to early Holocene volcanic activity from the nearby Mono Craters and are important chronostratigraphic markers for paleomagnetic, paleoclimatic, and paleoecologic studies. These stratigraphically important tephra deposits can be geochemically identified using compositions of their titanomagnetite phenocrysts. Titanomagnetite compositions display a broad range (XUsp 0.26–0.39), which allow the tephra layers to be distinguished despite the indistinguishable major-element glass compositions (76–77wt% SiO2) of their hosts. The concentrations of Ti and Fe in titanomagnetite display geochemical and stratigraphic groupings that allow clear discrimination between older (>57ka) and younger (<41ka) tephras. Some individual tephra layers can be uniquely identified on the basis of titanomagnetite MgO, MnO, and Al2O3 contents. In addition, a few tephra layers can be correlated to their source vents by their titanomagnetite compositions. The unique geochemical fingerprint of the Mono Craters-sourced titanomagnetites also allows the discrimination of two tephra layers apparently sourced from nearby Mammoth Mountain volcano in Long Valley.

Fluvial system response to external forcing and human impact – Late Pleistocene and Holocene fluvial dynamics of the lower Guadalete River in western Andalucía (Spain)

The 170 km long river course of the Guadalete River (western Andalucía) provides an excellent record of Late Pleistocene and Holocene fluvial sedimentation dynamics. Furthermore, its floodplain sediments are very well suited to describe geomorphic changes forced by climate fluctuations, sea‐level changes, tectonic influences and human activity. Multiproxy investigations were based on field mapping and the study of 18 profile sections, mainly including sedimentological characterisation, soil‐chemical analyses and radiocarbon dating of 34 samples. Findings were complemented by drillings and electrical resistivity tomography. The lowermost 50 km of the river section are divided into an upper and lower part (each 25 km long), based on different sediment preservation conditions. The boundary corresponds to the disappearance of the Late Pleistocene river terrace. Significant floodplain aggradation occurred at around 10 000 cal. years BP, while dynamics were strongly affected by sea‐level fluctuations until the early Holocene. Furthermore, sedimentation starting at 8000, 6100, 4600, 2200, 900 and 400 cal. years BP is related to enhanced fluvial dynamics due to environmental stress that presumably was triggered by climate fluctuations, that is, aridification. However, the strongest intensity of sedimentation at 400 cal. years BP points to climate anomalies in the course of the Little Ice Age. In contrast, several periods of stability associated with alluvial soil formation took place during the Bølling and Allerød interstadials, prior to 8000, 6100 and 5100, and after 4300 and 2000 cal. years BP. The anthropogenic signal in floodplain evolution is not clearly distinguishable from that of climate. However, human land use had the potential to amplify geomorphic processes, especially during periods of climate deteriorations that caused increasing stress on the environment.

The deglacial to postglacial marine environments ofSEBarrowStrait,CanadianArcticArchipelago

Core 86027‐144 (74°15.56′N, 91°14.21′W) represents a rare, continuous record ofLatePleistocene toHolocene sediments fromHighArcticCanada extending from the end of theLastGlaciation. Based on microfossils (dinocysts, non‐pollen palynomorphs, benthic and planktonic foraminifera), foraminiferalδ18Oandδ13C, and sedimentology, seven palaeoenvironmental zones were identified. ZoneI(&gt;10.8 cal. kaBP) records deglaciation, ice‐sheet destabilization, float‐off and subsequent break‐up. ZoneII(c. 10.8–10.4 cal. kaBP) shows ice‐proximal to ice‐distal glaciomarine conditions, interrupted by pervasive land‐fast sea‐ice marked by a hiatus in coarse sediment deposition. Significant biological activity starts in ZoneIII(10.4–9.9 cal. kaBP), where planktonic foraminifera (Neogloboquadrina pachyderma) suggest early oceanic throughflow. Surface waters flowedNW–SE; however, the deep‐water origin remains unclear (potentiallyNWArcticOcean orBaffinBay). Postglacial amelioration (open‐water season greater than present) in ZoneIV(9.9–7.8 cal. kaBP) perhaps corresponds to the regional ‘Holocene Thermal Maximum’ previously proposed. A transitional period (ZoneV; 7.8–6.7 cal. kaBP) of rapid environmental change fluctuating on a scale not observed today is marked by increasing sea‐ice and reduced oceanic influence. This probably signals the exclusion of deeperAtlantic water owing to the glacio‐isostatic shallowing of inter‐island sills, coupled with generally cooling climate. Conditions analogous to those at present, with increased sea‐ice and modern microfossil assemblages, commence atc.6.7 cal. kaBP(zonesVI–VII). Although climate ultimately forces long‐term environmental trends, core 86027‐144 data imply that regional dynamics, especially changes in sea‐level, exert a significant control on marine conditions throughout theCanadianArcticArchipelago.

A late Pleistocene and Holocene mineral magnetic record from sediments of Lake Aibi, Dzungarian Basin, NW China

We studied mineral magnetic properties of a 6-m-long, late Pleistocene through Holocene sediment sequence from Lake Aibi in Dzungaria (Zunggary, Junggar), northern Xinjiang, China. Results were used to infer environmental changes and are compared with previously studied cores from Lake Manas. Both water bodies occupy the deepest parts of the Dzungarian Basin and are remnants of large Holocene lakes. During the Late Pleistocene, the magnetic mineralogy in both lakes was dominated by detrital, iron oxide minerals. Oxic conditions, which dominated during sedimentation and early diagenesis, persisted over the Pleistocene–Holocene transition. Later, during the middle Holocene, lake bottom conditions enabled authigenic formation of iron sulphide minerals such as pyrite (FeS2) in Lake Aibi, and pyrite and greigite (Fe3S4) in Lake Manas. This iron sulphide mineralogy suggests increased biological activity in stagnant, anoxic bottom waters. Anoxic bottom conditions started about 9.8 cal kyr BP in Lake Manas and at about 7.2 cal kyr BP in Lake Aibi. A short dry event recorded in Lake Manas between 6.8 and 5.2 cal kyr BP is not clearly observed in Lake Aibi. In the late Holocene, i.e. the last 2.8 cal kyr, sediments of both lakes are again characterised by iron oxides, suggesting well-mixed, shallow water bodies. For this recent period, it seems that the detrital material in the two lakes had a common origin. Magnetic properties of sediments in Lakes Aibi and Manas show broadly similar environmental evolution during the late Pleistocene and Holocene. Nevertheless, despite the close proximity of the two lakes (~200 km) in the same basin, they display some different magnetic properties and record environmental changes at different times.

Raptor and owl bone from Niah Caves, Sarawak: identifications and morphological variation in the humerus and tarsometatarsus of selected raptors

AbstractThis paper reports on the findings of a preliminary investigation of raptor (Accipitriformes) and owl (Strigiformes) bones recovered during the original archaeological investigations of the Niah Caves during the 1950s and 1960s. Observations of morphological characteristics that were utilised to distinguish humeri and tarsometatarsi of selected species are included. A total of 48 archaeological specimens were identified, representing five genera of Accipitridae (Order Accipitriformes) and two genera of Strigidae (Order Strigiformes). Forty‐four specimens were further identified to species (Accipitriformes, four species; Strigiformes, three species) including a Late Pleistocene record of the bathawk (Machieramphus alcinus) dated to 36 470 ± 250 (uncal.) bp. Modern representatives of all identified species have been recorded recently in Sarawak. The relevance of raptors and owls in the palaeoecological reconstruction of this site is discussed, and the potential role of these birds as taphonomic agents is considered. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Record of Late Pleistocene (Oxygen Isotopic Stage 5) climate changes during episodes of karst development on the Northern coast of Crete: Sequence stratigraphic implications

In Late Pleistocene times, during Oxygen Isotopic Stage (OIS) 5, aeolian calcareous sand dunes were deposited along the northern coast of Crete, where they now discontinuously crop out wedged between thin shallow marine Tyrrhenian deposits. Late Pleistocene marine sediments are scarce and amalgamated because the combination of slow uplift movement and low elevation of OIS 5 highstand shorelines, close to present mean sea level, promoted their erosion in the shallow marine and subaerial environments. The studied succession is organized in transgressive–regressive (T–R) sequences bounded below and above by transgressive surfaces of erosion superimposed on subaerial unconformities. The vertical stacking of sedimentary facies between consecutive key surfaces demonstrates that the preservation potential of marine transgressive deposits (TST) was higher than that of regressive sediments. Similarly, aeolian strata and palaeosols located landward were well preserved. Detailed sedimentological and petrographic studies of the aeolianites and their framing units from several sites revealed a complex microstratigraphy of diagenetic features that relate to: (1) the succession of highstand shorelines during OIS 5; and (2) episodes of subsurface karstification interpreted to result from soil cover development on limestone substrate during relative sea-level falls. A complex sequence of climate changes during karst formation is suggested by solution pipes that cross-cut or contain calcified root systems, and whose inner walls are covered with carbonate crusts interpreted as calcretes. The repetition during OIS 5 of this transition from rhizocretion formation to karstification to calcretization in the studied deposits is argued to occur in response to contrasting climate conditions at times of sea-level lowstand. It is proposed that palaeosols and rhizocretions formed during the falling limb of the relative sea-level curve under semi-arid conditions, karstification developed at the turn between falling and rising sea level when climate was at its wettest, and calcretization occurred during the rising limb of the relative sea-level curve under arid conditions. Identification of wave-cut surfaces of erosion on top of transgressive marine sediments and below aeolian deposits, suggest that the latter are contemporaneous with falling sea-level marine units deposited basinward below the lowstand shoreline, namely forced regressive systems tracts (FRST), otherwise not recognized in the field. The complex suite of alteration processes recorded within the palaeosols above aeolian deposits are interpreted to represent periods extending from the latest stage of sea-level fall to the earliest stage of sea-level rise, including lowstand systems tracts (LST). This proves a satisfactory complement to reconstruct palaeosea-level fluctuations in settings where the shallow-marine nature of sedimentary environments means that most regressive and lowstand deposits are not recognized in the stratigraphic record.