Chronologies of sedimentary changes in the south Bohai Sea,China: constraints from luminescence and radiocarbon dating

The alternation of terrestrial and marine deposits is an indicator of past environmental and sea‐level changes. The age of deposition is usually dated by means of radiocarbon. However, radiocarbon dates of molluscan shells from coastal areas may be complicated by various sources of carbon, and problematic for deposits of 40–50 ka or older. Herein, we apply the Optically Stimulated Luminescence (OSL) dating method to date samples from terrestrial and marine/coastal sediments extracted from three cores in the south Bohai Sea, China. Multiple‐ and single‐aliquot regenerative‐dose procedures using OSL signals from fine‐silt (4–11 μm), coarse‐silt (38–63 μm) and fine‐sand (63–90 or 90–125 μm) quartz were employed to determine the equivalent dose (D _e). The results showed that: (i) OSL ages from quartz of different grain sizes and different protocols are consistent with each other; (ii) for Holocene samples, most of the radiocarbon dates agree well with OSL ages; (iii) for pre‐Holocene samples, radiocarbon dates cluster at 40–50 ¹⁴ C ka BP, whereas OSL ages are in stratigraphic order from 11 ka to 176 ka. Because of the self‐consistency of the quartz OSL ages, the stratigraphic agreement in the three cores, and the clustering of the radiocarbon dates, we suggest that the quartz OSL ages are more reliable with respect to dating the samples from the south Bohai Sea. Finally, the four marine strata identified in the south Bohai Sea are likely to have formed during the Holocene, Marine Isotopic Stage (MIS) 3–5, MIS 6 and probably MIS 7, respectively.     

Stratigraphy of Pleistocene glaciations in the St Elias Mountains,southwest Yukon,Canada

At least five Middle to Late Pleistocene advances of the northern Cordilleran Ice Sheet are preserved at Silver Creek, on the northeastern edge of the St Elias Mountains in southwest Yukon, Canada. Silver Creek is located 100 km up‐ice of the Marine Isotope Stage (MIS) 2 McConnell glacial limit of the St Elias lobe. This site contains ~3 km of nearly continuous lateral exposure of glacial and non‐glacial sediments, including multiple tills separated by thick gravel, loess and tilted lake beds. Infrared‐stimulated luminescence (IRSL) and AMS radiocarbon dating constrain the glacial deposits to MIS 2, 4, either MIS 6 or mid‐MIS 7, and two older Middle Pleistocene advances. This chronology and the tilt of the lake beds suggest Pleistocene uplift rates of up to 1.9 mm a^?1 along the Denali Fault since MIS 7. The non‐glacial sediment consists of sand, gravel, loess and organic beds from MIS 7, MIS 3 and the early Holocene. The MIS 3 deposits date to between 30–36 ¹⁴C ka BP, making Silver Creek one of the few well‐constrained MIS 3‐aged sites in Yukon. This confirms that ice receded close to modern limits in MIS 3. Pollen and macrofossil analyses show that a meadow‐tundra to steppe‐tundra mosaic with abundant herbs and forbs and few shrubs or trees, dominated the environment at this time. The stratigraphy at Silver Creek provides a palaeoclimatic record since at least MIS 8 and comprises the oldest direct record of Pleistocene glaciation in southwest Yukon.     

Lithostratigraphy and Optically Stimulated Luminescence age determinations of pre‐Late Weichselian deposits in the Suupohja area,western Finland

The lithostratigraphy of pre‐Late Weichselian sediments and OSL‐dating results from four localities in the Suupohja area of western Finland, adjacent to the centre of the former Scandinavian glaciations, are presented. The studied sections expose glacifluvial, quiet‐water, littoral and aeolian deposits overlain by Middle and/or Late Weichselian tills. Litho‐ and biostratigraphical results together with seven OSL age determinations on buried glacifluvial sediment at Rävåsen (94±15 ka) and on till‐covered littoral and aeolian sediments at Risåsen, Rävåsen, Jätinmäki and Kiviharju (79±10 to 54±8 ka), accompanied by previous datings and interpretations, suggest that the glacifluvial sediments at Risåsen were deposited at the end of the Saalian Stage (MIS 6) and those at Risåsen were deposited possibly in the Early Weichselian Substage (MIS 5d?). Palaeosol horizons and ice‐wedge casts together with the dated littoral and aeolian sediments between the Harrinkangas Formation (Saalian) and the overlying till(s) indicate that western Finland was ice‐free during most of the Weichselian time. Littoral deposits, dated to the Middle Weichselian (MIS 4–3), occur at altitudes of 50–90 m a.s.l., which indicates significant glacio‐isostatic depression. The depression resulted from expansion of the ice sheet in the west of Finland at that time.     

New interglacial deposits from Copenhagen,Denmark: marine Isotope Stage 7

During a pre‐site survey and construction of a new metro route and station in Copenhagen, fossiliferous organic‐rich sediments were encountered. This paper reports on multidisciplinary investigations of these organic sediments, which occurred beneath a sediment succession with a lower till, glacifluvial sand and gravel, an upper till and glacifluvial sand. The organic sediments were underlain by glacifluvial sand and gravel. The organic‐rich sediments, which were up to 0.5 m thick, accumulated in a low‐energy environment, possibly an oxbow lake. They were rich in plant fossils, which included warmth‐demanding trees and other species, such as Najas minor, indicating slightly higher summer temperatures than at present. Freshwater shells were also frequent. Bithynia opercula allowed the sediments to be put into an aminostratigraphical framework. The amino acid racemization (AAR) ratios indicate that the organic sediments formed during Marine Isotope Stage 7 (MIS 7), which is consistent with optically stimulated luminescence dating that gave ages of 206 and 248 ka from the underlying minerogenic deposit. The assemblages from Trianglen are similar to interglacial deposits from the former Free Port (1.4 km away) in Copenhagen, except that Corbicula and Pisidium clessini were not found at Trianglen. The presence of these bivalves at the Free Port and the ostracod Scottia tumida at Trianglen indicates a pre‐Eemian age. AAR data from archived Bithynia opercula from the Free Port were almost identical to those from Trianglen, indicating that the two sites are contemporary. We suggest the Trianglen interglacial be used as a local name for the MIS 7 interglacial deposits in Copenhagen. MIS 7 deposits have rarely been documented from the region, but MIS 7 deposits may have been mistaken for other ages. The use of AAR ratios in Bithynia opercula has a great potential for correlation of interglacial non‐marine deposits in mainland northern Europe.     

Environmental conditions in northwestern Russia during MIS 5 inferred from the pollen stratigraphy in a sediment core from Lake Ladoga

Lake Ladoga hosts preglacial sediments, although the Eurasian ice sheet overrode the area during the LGM. These sediments were first discovered by a seismic survey and are investigated using a 22.75‐m‐long core. Its upper 13.30 m comprise Holocene and Lateglacial sediments separated from the lower 11.45 m of preglacial sediments by a hiatus. They consist of highly terrigenous lacustrine sediments, which according to OSL dating, were deposited during an early stage of the last ice age (MIS 5). The palynological data allow a first reconstruction of the Early Weichselian environmental history for northwestern Russia. Birch and alder forests with broad‐leaved taxa dominated during MIS 5d (c. 118–113 ka), suggesting a climate more favourable than in the Holocene. A high content of well‐sorted sands and poorly preserved palynomorphs indicates a shallow‐water environment at least temporarily. More fine‐grained sediments and better preserved organic remains suggest deeper water environments at the core location during MIS 5c (c. 113–88 ka). Pine and spruce became dominant, while broad‐leaved taxa started to disappear, especially after c. 90 ka, pointing to a gradual climate cooling. An increase in open herb‐dominated habitats at the beginning of MIS 5b (c. 88–86 ka) reflects a colder and dryer climate. However, later (c. 86–82 ka) pine and spruce again became more common. Birch and alder forests dominated in the area c. 82–80 ka (beginning of MIS 5a). Although open treeless habitats also became more common at this time, a slight increase in hazel may point to somewhat warmer climate conditions coinciding with the beginning of MIS 5a. The studied sediments also contain numerous remains of freshwater algae and cysts of marine and brackish‐water dinoflagellates and acritarchs documenting that the present lake basin was part of a brackish‐water basin during the Early Weichselian, probably as a gulf of the Pre‐Baltic Sea.     

Pleistocene fluvial sediments,palaeontology and archaeology of the upper River Thames at Latton,Wiltshire, England

Pleistocene fluvial sediments of the Northmoor Member of the Upper Thames Formation exposed at Latton, Wiltshire, record episodic deposition close to the Churn–Thames confluence possibly spanning the interval from Marine Isotope Stages (MIS) 7 to 2. The sequence is dominated by gravel facies, indicating deposition by a high‐energy, gravel‐bed river. A number of fine‐grained organic sediment bodies within the sequence have yielded palaeoenvironmental and biostratigraphical data from Mollusca, Coleoptera, vertebrates, pollen and plant macrofossils. The basal deposit (Facies Association A) contains faunal material indicating temperate conditions. Most of the palaeontological evidence including a distinctive small form of mammoth (Mammuthus cf. trogontherii), together with the U‐series age estimate of >147.4 ± 20 kyr suggest correlation with MIS 7. The overlying deposits (Facies Associations B and C) represent deposition under a range of climatic conditions. Two fine‐grained organic deposits occurred within Association B; one (Association Ba) in the northern part of the pit as a channel fill and the other (Association Bb) in its southern part as a scour‐fill deposit. The coleopteran assemblages from Ba, indicate that it accumulated under temperate oceanic conditions, while Bb, which also yielded a radiocarbon age estimate of 39 560 ± 780 ¹⁴C yr BP, was formed under much colder and more continental climatic conditions. The sequence is considered to represent deposition within an alluvial fan formed at the Churn–Thames confluence; a depositional scenario which may account for the juxtaposition of sediments and fossils of widely differing age within the same altitudinal range. Copyright © 2006 John Wiley & Sons, Ltd.     

Geochemistry of Quaternary sediments of the Jeongokri archaeological site,Korea: implications for provenance and palaeoenvironments during the Late Pleistocene

The geochemical characteristics of an approximately 6‐m‐long sediment core collected from the Jeongokri archaeological site (Hantan River, Korea) were examined to determine the provenance of the sediments and to reconstruct the palaeoenvironment of the study area during the Late Pleistocene (200–127 ka). The core sediments were subdivided into two parts based on grain size: an upper (0–380 cm depth) and lower part (>380 cm depth). The lower part was deposited primarily by fluvial processes during an interglacial period [marine isotope stage (MIS) 7] with warm and humid conditions. Conversely, the upper part was mainly deposited by aeolian processes during a cold and dry glacial period (MIS 6). Geochemical characteristics, represented by major, trace and rare earth element (REE) compositions, and textures of the Jeongokri core sediments show distinct differences between the upper and lower parts. The mineralogy and major, trace and REE compositions indicate that the influence of felsic source rocks (e.g. granite) was dominant in the lower sediments, which were derived from the Hantan River. In contrast, increased quartz content and the very fine and homogeneous grain size in the upper sediments indicate an aeolian origin. REE ratios and distribution patterns, and geochemical signatures indicate that these sediments were derived predominantly from Chinese loess deposits and partially from local sediments from the Korean Peninsula; the possible source area of the upper sediments is the northern part of the Yellow Sea basin. The Yellow Sea basin, having mixed geochemical signatures between Chinese loess and Korean‐derived sediments, was exposed because of low sea levels during MIS 6. The exposed Yellow Sea basin was located in the path of winter‐monsoon winds, which may have carried a great deal of airborne sediments from the basin to the Jeongokri area. Copyright © 2011 John Wiley & Sons, Ltd.     

The age and stratigraphic context of the Easington Raised Beach, County Durham, UK

The Easington Raised Beach, in Shippersea Bay, County Durham, is the most northerly known interglacial beach deposit in England. It lies directly on Magnesian Limestone bedrock at 33 m O.D. and is covered by glacial sediments attributed to the Devensian. Detailed sedimentological analysis suggests that it is an interglacial beach, which is supported by the presence of pebbles bored by marine organisms and littoral, temperate-climate, marine macro- and micro-fossils. It comprises beds of unconsolidated, bedded, imbricated, well-rounded sands and gravels, overlain by similar, but calcreted, deposits. The gravel fraction is dominated by Magnesian and Carboniferous limestone, with orthoquartzite, flint, and porphyries also present; these are far-travelled erratics that must have derived from the erosion of older glacially transported sediments. Previous workers have described erratics derived from the Oslofjord region of Norway in the raised beach gravel, although rocks diagnostic of a Scandinavian origin have not been recovered as part of this study. The heavy-mineral suite is rich in epidote, dolomite, clinopyroxenes, garnet, tourmaline, and micas. The beach was dated previously by conventional amino acid analysis of the shells, which suggested a Marine Isotope Stage (MIS) 7 age, albeit with a reworked component from MIS 9. This has been confirmed by new optically stimulated luminescence (OSL) dates, which indicate that the beach formed between 240 and 200 ka BP. New amino acid racemisation analyses, using a modified technique, broadly support this interpretation but must await more comparative data before they can be assessed fully. The strong indication of an MIS 7 age for the formation of the beach has implications for the uplift history of northeastern England during the Pleistocene, and indicates an uplift rate of 0.19 mm a⁻¹. The stable isotope geochemistry indicates that the cementation occurred during an interglacial period, whilst U-Series dating of the cement indicates that cementation occurred mostly during the Holocene, and is genetically related to the overlying Devensian till. This work has formed part of a full re-appraisal of the glacial sequence in eastern County Durham, the results of which suggest that the Warren House Formation pre-dates the raised beach, and that the Devensian Horden Till overlies the raised beach.     

An absolute chronology for the raised beach and associated deposits at Sewerby,East Yorkshire,England

The raised beach sediments revealed in the cliffs at Sewerby, East Yorkshire are widely regarded as Ipswichian in age. Previously reported evidence for this dating is reviewed and new results from a range of luminescence dating techniques applied to the blown sand deposit overlying the raised beach are reported. These provide the first absolute date for the Sewerby site of 120.84 ± 11.82 ka, which places the blown sand at the boundary between oxygen isotope stages (OIS) 5e and 5d. As the underlying raised beach is little older than the blown sand, it probably formed during OIS Stage 5e as suggested by the faunal evidence.     

西沙群岛西科1井碳酸盐岩稳定同位素地层学

西科1井由于矿化重结晶作用和白云岩化作用普遍发育, 无法采用传统的氧同位素地层学方法进行地层年代标定.但是该井δ13C变化曲线与南海及全球主要大洋的碳同位素变化曲线完全相同, 可以用来准确标定200 ka以来的地层年龄.该井0~50 m深度对应全球氧同位素1~7期, 5 m处地层时代为14 ka, 为氧同位素1期的底界年龄; 11.70 m处为氧同位素2期的底界, 年龄为29 ka; 13.90 m深度年龄为57 ka; 到35.65 m为氧同位素6期底界, 年龄为191 ka, 同时δ13C值表现出冰期低而间冰期高的特点, 取自25.21 m的珊瑚U-Th定年年龄为131.062±2.320 ka.通过碳同位素定年发现, 石岛缺失近代5 ka以来的沉积物, 在间冰期向冰期转换时因海平面下降造成碳酸盐台地暴露剥蚀.全球气候变化是石岛碳酸盐台地δ13C值发生突变的主要原因.      

Optically stimulated luminescence age controls on late Pleistocene and Holocene coastal lithosomes, North Carolina, USA

Luminescence ages from a variety of coastal features on the North Carolina Coastal Plain provide age control for shoreline formation and relative sea-level position during the late Pleistocene. A series of paleoshoreline ridges, dating to Marine Isotope Stage (MIS) 5a and MIS 3 have been defined. The Kitty Hawk beach ridges, on the modern Outer Banks, yield ages of 3 to 2 ka. Oxygen-isotope data are used to place these deposits in the context of global climate and sea-level change. The occurrence of MIS 5a and MIS 3 shorelines suggests that glacio-isostatic adjustment (GIA) of the study area is large (ca. 22 to 26 m), as suggested and modeled by other workers, and/or MIS 3 sea level was briefly higher than suggested by some coral reef studies. Correcting the shoreline elevations for GIA brings their elevation in line with other sea-level indicators. The age of the Kitty Hawk beach ridges places the Holocene shoreline well west of its present location at ca. 3 to 2 ka. The age of shoreline progradation is consistent with the ages of other beach ridge complexes in the southeast USA, suggesting some regionally contemporaneous forcing mechanism.     

Highstands in the interior of the Qinghai–Tibetan Plateau since the last interglacial: evidence from grain‐size analysis of lacustrine core sediments in Zabuye Salt Lake

Highstands in the Marine Isotope Stage (MIS) 3 based on ¹⁴C dating in the Qinghai–Tibetan Plateau (QTP) are widely documented. Recent records from shoreline sediments dated using U‐series and/or optically stimulated luminescence (OSL), however, reveal that the highstands originally dated in MIS 3 should now be considered to fall in MIS 5. This paper provides new evidence from the interior of the QTP, based on the grain‐size from a continuous lake core in the Zabuye Salt Lake, to verify the MIS 5 highstand in the QTP. Grain‐size analysis of the core sediments also distinguishes two other highstands in MIS 3 and MIS 2, respectively. The MIS 5 highstand is considered as the maximum lake level since the Last Interglacial, as cored sediments contain very low values of Median Diameter (Md) during MIS 5. Compared with the discontinuous records from lake shorelines sediments, the grain‐size records from the continuous lake centre core sediments provide a more complete dataset to infer lake level variations, and make it possible to make wider palaeoclimatic and palaeoenvironmental interpretation. In the interior of the QTP, highstands might have continued into cold climate periods due to the reduced evaporation rates in the latter. The influence of the moisture‐bearing southerly‐shifted Westerly wind pathway may also have contributed to the highstands in the glacial period. Copyright © 2015 John Wiley & Sons, Ltd.     

Marine glacial and interglacial stratigraphy in Vendsyssel, northern Denmark: foraminifera and stable isotopes

The marine Quaternary of Vendsyssel has been studied in a series of new boreholes in the area, and the climatic development is discussed on the basis of foraminiferal assemblages and stable isotopes. The foraminiferal zones are correlated with previously published records from northern Denmark, and the spatial local and regional distribution is discussed in details based on the new evidence. The new data show that the marine sedimentation in Vendsyssel was not continuous from the Late Saalian to the Middle Weichselian, as previously thought. For example, there is indication of a hiatus at our key site, Åsted Vest in the central part of Vendsyssel, at the transition between regional foraminiferal zones N4 and N3, i.e. at the Late Saalian (MIS 6) – Eemian (MIS 5e) transition. The hitherto most complete Early Weichselian succession (zone N2) in Vendsyssel is presented from Åsted Vest. Deposits from the Early Weichselian sea‐level lowstands (MIS 5d and 5b) may, however, be missing in parts of the area. Two major breaks in the marine deposition during the Middle Weichselian represent glacial advances into northern Denmark. The first event occurred just after deposition of the regional foraminiferal zone N2 (late MIS 4), and the second event in the middle part of zone N1 (early MIS 3). Zone N1 is succeeded by a series of non‐marine units deposited during the sea‐level lowstand of the Weichselian maximum glaciation (late MIS 3 and MIS 2), including deeply incised tunnel valleys, which have been refilled with non‐marine sediments during the Late Weichselian. Vendsyssel was inundated by the sea again during the Late Weichselian, at c. 18 kyr BP. Subsequently, the marine conditions were gradually changed by forced regression caused by local isostatic uplift, and around the Weichselian–Holocene transition most of Vendsyssel was above sea level. A continuous deposition across the Late Weichselian–Holocene boundary only occurred at relatively deep sites such as Skagen. The environmental and climatic indications for Vendsyssel are in accordance with the global sea‐level curve, and the Quaternary record is correlated with the oxygen isotope record from the NorthGRIP ice core, as well as the marine isotope stages.     

Late Pleistocene and Holocene environmental changes in the coastal zone of northwestern Portugal

This paper examines the Quaternary changes in the coastal zone of northwestern Portugal through the relationship between sediments and landforms. By interpolating the available data from geomorphology, lithostratigraphy, sedimentology and geochronology, it was possible to reconstruct existing palaeoenvironments, the oldest of which date back to the last interglacial. The main landforms are a high and a low platform bounded by scarps. River sands and silty sediments formed in a lacustrine environment (Antas Formation, MIS 5) are associated with the high platform. Two deposits are associated with the low platform: the Cepães Formation (MIS 3) consisting of a lower set of river sand beds and an upper gravel beach bed, and the Aguçadoura Formation (MIS 1) consisting of Holocene lagoonal beds. Copyright © 2006 John Wiley & Sons, Ltd.     

Dating fluvial erosion: fluvial response to climate change in the Moselle catchment (France,Germany) since the Late Saalian

This paper focuses upon the youngest terraces of the Moselle and its tributary the Meurthe (NE France and SW Germany). It includes research on several sections, in particular the key sections of Golbey‐Pré Droué and Thörnich‐Hochrech (located in the vicinity of the Vosges Massif and in the Rhenish Massif, respectively), and the use of the Optically Stimulated Luminescence (OSL) dating method. Our investigations made it possible to obtain a more robust chronostratigraphical framework and to update the previous model of fluvial response to climate change. The results demonstrate that the Moselle terrace M3 (first terrace formed after the capture of the Upper Moselle by the Palaeo‐Meurthe) has the same age from the Vosges to the Rhenish Massif. The formation of this terrace included two main periods of sedimentation attributed to the Late Saalian (MIS 6) and the Early Weichselian (MIS 5), respectively. They were separated by a major episode of fluvial erosion that may be allocated to the MIS 6–5 transition on the basis of chronological and sedimentological evidence. This erosion led to the removal of most of the MIS 6 deposits, whereas the MIS 5 deposits have been widely preserved following the subsequent (MIS 5–4) terrace incision. This evolution somewhat contrasts with that observed in the Sarre valley, the main tributary of the Moselle, and with many fluvial systems in western Europe, which show better preservation of deposits from cold periods. This atypical behaviour is explained by the relationship between the fluvial evolution and the glaciers covering the upper Moselle catchment (Vosges Massif) during the Pleistocene cold periods.     

River sections at the Byzovaya Palaeolithic site – keyholes into the late Quaternary of northern European Russia

Heggen, H. P., Svendsen, J. I. & Mangerud, J. 2009: River sections at the Byzovaya Palaeolithic site – keyholes into the late Quaternary of northern European Russia. Boreas, 10.1111/j.1502‐3885.2009.00109.x. ISSN 0300‐9483. The geological history of northern European Russia over the past two glacial cycles is reconstructed from the stratigraphy in river bluffs along the upper reaches of the Pechora River. From a till bed near the base of the sections it is inferred that the Barents–Kara Ice Sheet covered the area during the late Saalian (MIS 6). After deglaciation, and prior to the last interglacial, the area was flooded by an ice‐dammed lake, suggesting that the Pechora Basin was blocked by a subsequent ice advance at the very end of the Saalian. Ice‐wedge casts and periglacial sediments reflect a pronounced cooling with formation of permafrost during the Early Weichselian (MIS 5d). An overlying thick sequence of shallow lacustrine sediments accumulated in the ice‐dammed Lake Komi, formed by the advancing Barents–Kara Ice Sheet 80–100 kyr BP (MIS 5b?). Following drainage of the lake, many of the older formations were eroded by fluvial activity. Animal remains found together with palaeolithic artefacts within debrisflow sediments at the base of one of the incised gullies yielded radiocarbon ages around 28 000–30 000 ¹⁴C yr BP (33–34 cal. kyr BP). The surface with traces of human activities was subsequently covered by aeolian sediments representing the northern extension of the European belt of periglacial coversand that accumulated in the cold and dry climate during the late Weichselian (MIS 2). The results of this work confirm the assumption that the last shelf‐centred ice sheet that covered this part of Russia occurred during the late Saalian (MIS 6), but that this glaciation was followed by a younger and less extensive ice advance that has not been described before. There are no indications that local glaciers originating in the Ural Mountains reached the Pechora River valley throughout the last two glacial cycles.     

Late Quaternary Paleoclimatic Change in the Ulleung Basin, East Sea, Korea

Paleoclimatic changes in the late Quaternary sediments deposited in the East Sea were analyzed by studying diatoms. A total of 95 species belonging to 47 genera were identified from the Core02GHP-02 of the Ulleung Basin in the East Sea, Korea. In the Core 02GHP-02, U-Oki(169–181 cm; 9.3 ka), AT(464–465.5 cm; 22 ka) and U–Ym(556–559 cm; 33 ka) tephra layers were recognized. The chronological divisions of 02GHP-02 may be correlated with the climatic changes from the glacial interval(730–620 cm; MIS3), to interstadial(620–500 cm; MIS3), to the last glacial maximum(500–390 cm; MIS 2), to the deglaciation(390–290 cm; MIS 2), to the late glacial(290–190 cm; MIS 1), and to the Holocene(190–10 cm; MIS 1). It is speculated that diatoms were rarely found during the glacial interval when the 02GHP-02 core was deposited; during the interstadial(MIS 3) and deglaciation, a mixture of warm-water and cold-water species were found. In particular, Fragilariopsis doliolus seems to have appeared in the East Sea after 8 ka BP. In the lower layers of the Holocene deposits, cold-water species such as Neodenticula seminae were frequently found, while in the upper layers, warm-water species such as Hemidiscus cuneiformis were found in relatively large abundance. Therefore, the findings indicate that the climate became warmer during the transition from the lower layer to the upper layer of the Holocene deposits.     

Vegetation history of the penultimate glacial period (Marine isotope stage 6) at Ioannina,north‐west Greece

The vegetational history of the penultimate glacial period, Marine Isotope Stage (MIS) 6 (c. 185–135 ka), has remained relatively unexplored. Here we present a new record from the Ioannina basin, north‐west Greece, which constitutes the highest‐resolution terrestrial pollen record for this interval produced to date. It shows that the vegetation history of MIS 6 in this region can be divided into two parts: an early period (185–155 ka) with pronounced oscillations in tree population extent, and a later period (155–135 ka) with much smaller tree populations and subdued oscillations. This pattern is analogous to the MIS 3/MIS 2 division during the last glacial in the same sequence, although the early part of MIS 6 had larger Pinus populations and fewer temperate trees relative to the equivalent interval in MIS 3. This implies cooler and wetter conditions, which is somewhat counterintuitive given the high summer insolation during MIS 6e, but is in line with other palaeoclimatic evidence from the Mediterranean. Comparison with North Atlantic records suggests that despite the absence of pronounced iceberg discharges during MIS 6, North Atlantic millennial‐scale variability had a significant downstream impact on tree populations in north‐west Greece. Copyright © 2011 John Wiley & Sons, Ltd.     

Sedimentology and stratigraphy of a transgressive, muddy gravel beach: Waterside Beach, Bay of Fundy, Canada

Sediments exposed at low tide on the transgressive, hypertidal (>6 m tidal range) Waterside Beach, New Brunswick, Canada permit the scrutiny of sedimentary structures and textures that develop at water depths equivalent to the upper and lower shoreface. Waterside Beach sediments are grouped into eleven sedimentologically distinct deposits that represent three depositional environments: (1) sandy foreshore and shoreface; (2) tidal‐creek braid‐plain and delta; and, (3) wave‐formed gravel and sand bars, and associated deposits. The sandy foreshore and shoreface depositional environment encompasses the backshore; moderately dipping beachface; and a shallowly seaward‐dipping terrace of sandy middle and lower intertidal, and muddy sub‐tidal sediments. Intertidal sediments reworked and deposited by tidal creeks comprise the tidal‐creek braid plain and delta. Wave‐formed sand and gravel bars and associated deposits include: sediment sourced from low‐amplitude, unstable sand bars; gravel deposited from large (up to 5·5 m high, 800 m long), landward‐migrating gravel bars; and zones of mud deposition developed on the landward side of the gravel bars. The relationship between the gravel bars and mud deposits, and between mud‐laden sea water and beach gravels provides mechanisms for the deposition of mud beds, and muddy clast‐ and matrix‐supported conglomerates in ancient conglomeratic successions. Idealized sections are presented as analogues for ancient conglomerates deposited in transgressive systems. Where tidal creeks do not influence sedimentation on the beach, the preserved sequence consists of a gravel lag overlain by increasingly finer‐grained shoreface sediments. Conversely, where tidal creeks debouch onto the beach, erosion of the underlying salt marsh results in deposition of a thicker, more complex beach succession. The thickness of this package is controlled by tidal range, sedimentation rate, and rate of transgression. The tidal‐creek influenced succession comprises repeated sequences of: a thin mud bed overlain by muddy conglomerate, sandy conglomerate, a coarse lag, and capped by trough cross‐bedded sand and gravel.     

The Oldest Evidence for Human Habitation in the Baltic Region: A Preliminary Report on the Chronology and Archaeological Context of the Riadino‐5 Archaeological Site

We report the discovery of the oldest evidence for human presence in the southeastern Baltic Sea region. This paper presents an overview of the Riadino‐5 archaeological site in the lower course of the Šešupė River (Kaliningrad Oblast of Russia) and direct infrared stimulated luminescence (IRSL) ages for the culture‐bearing sediments from the site, which place the time of occupation well within the range of Marine Isotope Stage (MIS) 3 (ca 57–26 ka). Luminescence ages were determined using the multiple‐aliquot additive‐dose technique, applied to sand‐sized potassium feldspar. Four of the six IRSL samples from the site come from the cultural deposits, while two are from the surrounding sediments. The luminescence age of the deposits implies that human occupation of the southeastern Baltic Sea region occurred at least between 50 ka and 44 ka during the first half of MIS 3 and the Middle‐Upper Paleolithic.