correlation of fluvial sequences in the mediterranean basin over the last 200 ka and their relationship to climate change macklin mark fuller i c lewin j maas g a 2002 correlation of fluvial sequences in the mediterranean basin over the last 200 ka and their relationship to climate change quaternary science reviews 21 14 15 pp 1633 1641 rae2008

quaternary glaciation of the lato massif zanskar range of the nw himalaya abstract the glacial chronostratigraphy and history of the lato massif of zanskar northern india is defined for the first time using geomorphic mapping and 10be surface exposure dating three local glacial stages the lato shiyul and kyambu are dated to 244 49 25 15 and 3 4 0 2 ka respectively the lato glacial stage was the most extensive period of glaciation characterized by expanded ice caps with glaciers advancing to 16 km from their present position large till deposits are associated with this glacial stage which represent a time of heightened glacial erosion and localized incision and increased rates of sediment transfer and deposition the glacial style transitioned to entrenched valley glaciation during the shiyul glacial stage hummocky moraine complexes reflecting fluctuating glacier margins characterize this glaciation glaciers have been confined to the cirques and headwalls of the massif during and since the kyambu glacial stage equilibrium line altitude ela reconstructions help define the shifts in glaciation over time with ela depressions changing from 470 140 270 80 to 100 30 m for the lato shiyul and kyambu glacial stages respectively the change of glacial style during the latter part of the quaternary is similar to other regions of the transhimalaya and tibet suggesting that this pattern of glaciation may reflect regional climatic forcing the evolution of the lato massif from an isolated alpine plateau to a steeply incised massif over the last several glacial interglacial cycles may have also influenced the shifts from ice cap to valley glaciation

a case for a downwasting mountain glacier during termination i vercenik valley northeastern turkey field evidence of palaeoglacial records in the vercenik valley in the eastern black sea mountains was examined and 19 samples for surface exposure dating with cosmogenic 10 be were collected with the aim of increasing knowledge on the amplitude and frequency of palaeoglacier advances in anatolia glacial erosional features were mapped and the flow directions of the palaeoglaciers were determined the vercenik palaeoglacier advanced before 26 1 k 1 2 k yr the last glacial maximum lgm advance continued until 18 8 k 1 0 k yr the vercenik palaeo glacier collapsed during termination i after 17 7 k 0 8 k yr there was no more ice in the main valley the vercenik palaeoglacier most probably then separated into five small glaciers that were restricted to the tributary valleys among these the hemsin palaeoglacier completed its recession around 15 7 k 0 8 k yr on the basis of glacial erosion features a lateglacial glacier advance can be identified evidence of the little ice age advance appears to be absent the results from this valley system seem to be consistent with the first results from the adjacent kavron valley and with the anatolian lgm palaeoclimate the sea surface temperature minima in the western mediterranean the deposition of red clay layers in the black sea and deposition of the heinrich 1 layer in the north atlantic copyright 2007 john wiley sons ltd

cold and wet last glacial maximum on mount sandiras sw turkey inferred from cosmogenic dating and glacier modeling abstract in situ cosmogenic 36 cl was measured in boulders from moraines on mount sandiras 37 1 n 28 8 e 2295 m the southwestern most previously glaciated mountain in turkey valleys on the north side of the mountain were filled with 1 5 km long glaciers that terminated at an altitude of 1900 m the glacial activity on mount sandiras correlates with the broadly defined last glacial maximum lgm the maximum glaciation occurred approximately 20 4 1 3 ka 1 1 ka 1000 calendar years ago when glaciers started retreating and the most extensive moraines were deposited the glaciers readvanced and retreated by 19 6 1 6 ka ago and then again by 16 2 0 5 ka using the glacier modeling and the paleoclimate proxies from the eastern mediterranean we estimated that if temperatures during lgm were 8 5 11 5 c lower than modern precipitation was up to 1 9 times more than that of today thus the local lgm climate was cold and wet which is at odds with the conventional view of the lgm as being cold and dry in the region

fluvial response to late quaternary climatic and environmental change edwards plateau texas abstract radiocarbon controlled late pleistocene to modern stratigraphic frameworks for fluvial systems that drain the edwards plateau westcentral texas coupled with reconstruction of climatic and environmental changes permit development of a model for the evolution of fluvial landscapes during the past 20 000 years during this time large valleys of the edwards plateau were characterized by channel aggradation and sediment storage from 20 to 14 000 yrs b p deep excavation of bedrock valleys from ca 14 to 11 000 yr b p and deposition of extensive and complex valley fills during the last 11 000 yr valley fills contain three distinct unconformity bounded allostratigraphic units representing episodes of channel aggradation and floodplain construction during the early to middle ca 11 000 5000 yr b p and late holocene ca 5000 1000 yr b p and development of the incised channels and associated narrow floodplains of the last 1000 years early to middle holocene alluvial deposits were derived from proximal sources within the respective drainage basins whereas late holocene deposits include sediments derived from distal sources sediment supply to major valleys axes has been extremely limited during the last 1000 years alluvial sequences of the edwards plateau record fluvial responses to climatically driven changes in discharge regimes and the concentration of sediments along valley axes allostratigraphic units define time periods when the concentration of sediment exceeded stream power resulting in sediment storage whereas unconformities record widespread morphological and sedimentary adjustments unconformities between late pleistocene alluvium and holocene valley fills record bedrock valley incision in response to decreased sediment loads associated with slope stability in the uplands by contrast unconformities within the holocene valley fill record floodplain abandonment accompanied by continued channel migration and sediment storage but little additional bedrock valley cutting episodes of floodplain abandonment occurred as a result of decreased flood magnitudes following shifts to drier climatic conditions at ca 5000 and 1000 yr b p fluvial responses to climatic change were conditioned by a progressive degradation of upland soils that caused increases through time in the flashiness of flood events which in turn led to changes in processes of floodplain construction flood events on late pleistocene and early to middle holocene rivers were for the most part contained within channel perimeters and floodplains were constructed by lateral migration by contrast late holocene rivers were characterized by deep overbank flooding and floodplain construction by vertical accretion high magnitude floods were most significant from ca 2500 to 1000 yr b p when large chute channels were cut and filled on floodplain surfaces and soils developed on previously stable terrace surfaces were buried by up to 2 m of fine sands and muds

is there evidence for global scale forcing of southern hemisphere quaternary desert dune accumulation a quantitative method for testing hypotheses of dune system development luminescence dating of desert dune sediments has generated many hundreds of ages many used in reconstructions of quaternary environmental changes others in attempts to elucidate dune processes environmental and climatic interpretations of these records have proved problematic and it remains challenging to test hypotheses of the systematic response of dunefields to changes in external forcing in the past and to make predictions of the future we use a method that quantifies dune sediment accumulation to interpret dune luminescence age datasets rather than simply using the ages themselves as proxies of change the accumulation intensity method allows periods of dune sediment accumulation here over the timescale 102 105 years to be identified from compilations of dated sand sea stratigraphic sequences we apply this approach to two of the largest dune age datasets from southern africa and australia testing whether or not dunefield accumulation has co varied in the late quaternary and whether systematic relationships to external drivers at global hemispheric regional and local scales can be identified

glacial history of mt chelmos peloponnesus greece mt chelmos in the peloponnesus was glaciated by a plateau ice field during the most extensive pleistocene glaciation valley glaciers radiated out from an ice field over the central plateau of the massif the largest glaciations are likely to be middle pleistocene in age smaller valley and cirque glaciers formed later and boulders on the moraines of these glacial phases have been dated using 36cl terrestrial cosmogenic nuclide exposure dating these ages indicate a late pleistocene age with glacier advance stabilization at 40 30 ka glacier retreat at 23 21 ka and advance stabilization at 13 10 ka this indicates that the glacial maximum of the last cold stage occurred during marine isotope stage 3 several thousand years before the global last glacial maximum marine isotope stage 2 the last phase of moraine building occurred at the end of the pleistocene possibly during the younger dryas

karst landscape evolution in the littoral area of the bay of biscay north iberian peninsula the western pyrenean area contains extensive karst areas however their genesis and development are still mostly unknown in this work we make a general description of the karst landscape in different karst areas 1 rasa type 2 cone type karst and 3 alpine type karst the first two types are present in the littoral area where geomorphological evolution mostly depends on sea level and climatic changes we focused our study in two karst areas of the littoral cone type karst we correlate different caves created from different stable water table levels three representative caves are studied in detail studying their stratigraphic record based on allostratigraphy finally we dated the different phases of speleothem formation in the three caves using all this information we defined four stable paleowater table levels at 50 150 220 and 350 m asl controlled by sea level changes and isostatic uplift events the lowest level is the youngest with an age of c 1 ma we discovered that the interior of the three caves display very similar endokarst allostratigraphic sequences characterized firstly by an erosion phase a fluvio karst input flowstone speleothem formation and finally dripping speleothem formation the chronological data shows a correlation between these phases and pleistocene climatic phases the erosion phase is related to the falling sea level fluviokarst detrital input is related to cold glacial stages and the formation of speleothems is related to the warmest interglacial moments and high sea level periods

reconstruction of a complex late quaternary glacial landscape in the cordillera de cochabamba bolivia based on a morphostratigraphic and multiple dating approach abstract although glacial landscapes have previously been used for the reconstruction of late quaternary glaciations in the central andes only few data exist for the eastern cordillera in bolivia here we present results from detailed morphostratigraphic mapping and new data of surface exposure dating sed optically stimulated luminescence osl and radiocarbon dating 14 c from the huara loma valley cordillera de cochabamba bolivia discrepancies between individual dating methods could be addressed within the context of a solid geomorphic framework we identified two major glaciations the older is not well constrained by the available data whereas the younger glaciation is subdivided into at least four major glacial stages regarding the latter a first advance dated to 29 25 ka occurred roughly contemporaneous with the onset of the global last glacial maximum lgm and was followed by a less extensive re advance around 20 18 ka the local last glacial maximum llgm in the huara loma valley took place during the humid lateglacial 17 16 ka followed by several smaller readvances until 10 11 ka and complete deglaciation at the end of the early holocene

late pleistocene glaciations in the northwestern sierra nevada california pleistocene fluvial landforms and riparian ecosystems in central california responded to climate changes in the sierra nevada yet the glacial history of the western sierra remains largely unknown three glacial stages in the northwestern sierra nevada are documented by field mapping and cosmogenic radionuclide surface exposure crse ages two crse ages of erratic boulders on an isolated till above bear valley provide a limiting minimum age of 76 400 3800 10be yr another boulder age provides a limiting minimum age of 48 800 3200 10be yr for a broad crested moraine ridge within bear valley three crse ages producing an average age of 18 600 1180 yr were drawn from two boulders near a sharp crested bouldery lateral moraine that represents an extensive tioga glaciation in bear valley nine crse ages from striated bedrock along a steep valley transect average 14 100 1500 yr and suggest rapid late glacial ice retreat from lower fordyce canyon with no subsequent extensive glaciations these ages are generally consistent with glacial and pluvial records in east central california and nevada

unravelling the patterns of alluvial fan development using mineral magnetic analysis examples from the sparta basin lakonia southern greece mineral magnetic analysis of b horizons of soils developing upon the surfaces of alluvial fans was undertaken in order to i differentiate and rank discrete fan surfaces by order of formation ii establish whether fan surfaces formed simultaneously in adjacent fan systems and iii deduce probable patterns of fan development the results of the analysis indicate that the greatest concentration of ferrimagnetic and anti ferromagnetic minerals occurs within soils which have developed upon the proximal fan surfaces with a progressive reduction in magnetic minerals in soils associated with medial and distal surfaces the build up of magnetic minerals in the proximal fan soils suggests that these surfaces formed first followed by the medial and distal surfaces with the exception of the kalivia sokas fan the majority of depositional events responsible for fan surface formation occurred simultaneously suggesting that adjacent fan systems share broadly similar depositional histories although the precise timing of depositional events is uncertain it is probable that by the end of the late pleistocene small largely undissected fans comprising two to three surfaces had formed at the start of the holocene fan systems experienced significant fanhead incision a net distal extension of the fan trench coupled with a progressive basinward shift of the locus of deposition during the middle and late holocene resulted in formation of medial and distal fan surfaces changes in climate are deemed to be the major control of fanhead incision fan trenching and fan surface formation however the likely effects of long term tectonic activity and approximately five thousand years of human occupation upon fan development in the sparta basin remain unclear copyright 2000 john wiley sons ltd

glacial deposits in great britain and ireland with the increasing awareness of environmental problems there is a growing desire for a de tailed understanding of superficial deposits in general and glacial deposits in particular this is because these sediments have a profound influence on groundwater protection waste management and nature conservation they are also of vital importance to civil engineering because they provide the foundation for as well as the materials extracted to build our roads and buildings the greater part of the british isles was glaciated at least once during the quater nary era in the regions subjected to glaciation glacial deposits underlie much of the present land surface although there have been many recent publica tions on various quaternary geological topics the present volume is the first dedicated to a detailed assessment of the glacial deposits of britain and ireland after introductory chapters presenting the glacial history the sedimentary sequences in 24 critical regions are discussed these regions include all of ireland the gla ciated area of great britain and the adjoining offshore region of the north sea the controver sial evolution of the irish sea basin during the last glaciation is discussed from various view points a collection of critical topics presented in the later part of the book range from the classification of glacigenic landforms and de posits to the results of geophysical geotechnical and geochemical analyses the book includes 368 figures 40 tables and 51 colour photographs a detailed index and a list of over 1000 references with 45 contributions by 48 scientists this volume represents a truly contemporary view of this field of research to gether with its companion volume the glacial deposits in north west europe this book pro vides an excellent textbook for the advanced student or the amateur as well as an indispen sible source and guidebook for the professional scientist

paleoshoreline geomorphology of boon tsagaan nuur tsagaan nuur and orog nuur the valley of lakes mongolia abstract we conducted a preliminary study of paleoshoreline features associated with boon tsagaan nuur tsagaan nuur and orog nuur lakes located in the gobi altai transition zone of the valley of lakes dolina ozor which stretches from central to western mongolia the paleoshoreline features were first identified on radarsat satellite sar imagery we investigated the features during the 1998 field season of the joint mongolian russian american archaeological expedition to the gobi altai region we identified paleoshorelines of multiple elevations in the field which are considered to be relict beach ridges and wave cut terraces other paleolake landforms include spits and gilbert type deltas these landforms are complex large and well established implying that the paleolakes were stable for extended periods the reconstructed paleolakes cover extensive areas of the valley floor implying that hydrological and climatic conditions were very different in the past paleolake expansions may have occurred under a variety of circumstances one hypothesis is that the high lake stands occurred during the wetter period corresponding to the oxygen isotope stage 3 prior to the last glacial maximum lgm during the warmest early holocene and the late holocene or during all these periods if low evaporation rates due to lower temperatures glacier meltwater and possibly increased precipitation are important factors then the expansions may have occurred during the terminal late glacial period after the last glacial maximum the greatly expanded lakes in the gobi altai could have significantly affected the quaternary human demography and migration in the region

internal architecture of a till sheet tiskilwa formation north central illinois usa application of architectural element analysis thick till sheets deposited during the quaternary form significant aquitards in many areas of north america however the detailed sedimentary heterogeneity and architecture and depositional history of till units are not well understood this study utilizes architectural element analysis to delineate the internal sedimentary architecture of the tiskilwa formation exposed at two outcrop sections in north central illinois usa architectural element analysis facilitates systematic delineation of sedimentary architecture based on the nature of facies contacts and change in facies associations delineation of unit geometries and understanding of depositional processes at different scales of resolution making architectural element analysis suitable for the sedimentological analysis and palaeoenvironmental reconstruction of subglacial deposits eleven facies types are identified in this study including sand gravel and diamict facies that record a suite of subglacial depositional processes detailed analysis of facies contacts bounding surface hierarchy and change in facies associations allows the delineation of five architectural elements including coarse grained lens coarse grained sheet mixed zone diamict lens and diamict sheet elements the spatial arrangement and genetic interpretation of elements and their spatial relationship with fifth order bounding surfaces allows the delineation of five larger scale architectural units element associations which can be mapped in the local study area and record at least three stacked successions of meltwater accumulation and till deposition the results of this study can be utilized for architectural analysis of till sheets and provide insight to groundwater flow pathways through till in the study area and elsewhere

from valley to marginal glaciation in alpine type relief lateglacial glacier advances in the piec stawow polskich roztoka valley high tatra mountains poland abstract the piec stawow polskich roztoka valley in the high tatras western carpathians features typical alpine type relief with a deeply incised glacial trough and large compound trough head cirque the prominent hypsographic maximum in the valley 1680 2000 m along with a broad cirque bottom had provided a vast space for recording glacial and periglacial landforms specifically the most recent lateglacial advances the valley has been intensively studied before in the context of glacial chronology in this paper we re establish the post last glacial maximum lgm glacial chronology of the valley via detailed geomorphologic mapping equilibrium line altitude ela reconstruction and schmidt hammer sh dating along with a critical review of previously published cosmogenic exposure age data 36 cl and lacustrine sediment chronology our results indicate that the first four of the five distinguished lateglacial stages roztoka i iii pusta i occurred before the bolling allerod b a interstadial thus virtually the entire valley became deglaciated in course of the oldest dryas cold phase a distinct reorganization of deglacial patterns from valley type to marginal type occurred before b a warming when the ela increased above the valley hypsographic maximum concentrated at the cirque bottom elevation it shows that noticeable deglaciation step can be caused due to topographic reason with a minimal climate forcing this points also to an important role of glaciated valley hypsography in regulating the distribution of moraines which is rarely taken into account in paleoglaciological reconstructions we infer that glaciers vanished in the tatra mountains during the b a interstadial later a renewed advance during the younger dryas pusta ii formed a nearly continuous festoon shaped pattern of moraines and rock glaciers in close distance to cirque backwalls furthermore we discus some paleoenvironmental significance of the geomorphological record in the valley as well the applicability of sh dating in constructing glacial chronology

quaternary glaciations of northern europe this paper presents the outcome of a workshop held in berlin in february 2009 concerned with current research on the glacial history of northern europe including the british isles the methodologies presently used to resolve this topic are outlined particular attention is given to new analytical methods deriving from high resolution remote imaging of glacial terrain both on land and on the sea bed key new stratigraphic sections higher resolution results from conventional geochronological methods like radiocarbon and more recently developed technologies such as luminescence and cosmogenic radionuclide dating the relationships between the results derived from these two methods are discussed in further detail along with possible explanations for these differences an outline of a most likely glacial history of the scandinavian and british and irish ice sheets is presented along with possible links to global climate change as represented by the marine isotope mis record tentative evidence for glaciation is identified in mis 22 16 12 10 8 6 4 and 2 and correlations of phases within the last glaciation are also explored for both the scandinavian and british and irish ice sheets the results show that the character and extent of glaciation in different parts of the region are not synchronous and much more geochronological work is required before regional correlations can be established with confidence

pleistocene stratigraphy in the southern lower mississippi valley abstract scientific inquiry into pleistocene stratigraphy of the lower mississippi valley lmv dates to early writings of european naturalists in the late 19th century by the early 20th century landscape evolution concepts stratigraphic models and regional syntheses had developed for most areas the 1944 monograph of h n fisk marks the advent of a predictive stratigraphic and landscape evolution model that links form and process to a predominantly glacioeustatic mechanism the fiskian model gained widespread acceptance and decades passed before significant alternate models began to emerge revised stratigraphic and geomorphic concepts are presently developing from newly acquired environmental and engineering data present scenarios classify pleistocene outcrop areas into erosional and constructional landscapes and veneers of eolian colluvial fluvial coastal and marine origin can drape both types of surfaces the southern lmv and adjacent gulf coastal plain gcp experienced significant landscape change during the pleistocene late tertiary pliocene to early pleistocene deposition of the upland complex was by streams with a high sand and gravel load relative to its mud load the regional drainage network and fluvial system behavior was probably significantly different from the modern braided stream alluvial fan complexes received sediment from highland source areas adjacent to the lmv and the glaciated mid continent it is plausible that part of upland complex deposition predates initial glacial advances from early to middle pleistocene an erosional landscape formed during a dissection period that chiefly postdates soil formation on stable landscape positions of the upland complex slope evolution truncated a regionally extensive geosol in multiple phases and parts of the erosion surface complex are graded to the oldest preserved constructional alluvial plains in present valleys toe and foot slope positions of the erosion surface complex and its correlative alluvial plains are presently delineated as the intermediate complex constructional landscapes formed at this time are sparsely preserved fisk s montgomery terrace in the lower red river valley lrrv is the best preserved example influences on the development of erosion surfaces in the lmv are not well understood however interactions of relative sea level fall climate change and epirogenic crustal movement are plausible factors from the latter part of middle pleistocene to the holocene there was widespread evolution of modern constructional landscapes constructional alluviation preserved lithofacies of mixed load laterally accreting meandering streams that developed over large areas of the southern lmv to form parts of the prairie complex lateral planation in valleys and stable rates of upland sediment generation were dominant processes during prairie complex deposition pleistocene stratigraphic examples considered important by fisk are still considered relevant to modern stratigraphic investigators presently pleistocene units of the southern lmv the adjacent lrrv and central gcp can be correlated only by relative stratigraphic relationships refined chronostratigraphic and paleoenvironmental models for these areas would help improve the understanding of the geomorphic influences on quaternary landscape evolution in the region

holocene lake mega chad palaeoshorelines from space during the holocene a giant lake known as lake mega chad lmc extended over more than 350 000 km2 in southern sahara morphodynamic features of sedimentary systems outlining the lmc palaeoshorelines have been identified by the joint analyses of new topographic images digital elevation model acquired by radar interferometry and landsat thematic mapper images here we characterize for the first time at the scale of the chad basin a wave dominated sedimentary system including river deltas longshore sandridges beach ridges spits and a wave ravinement surface they provide new evidence of the environmental impact of quaternary climate changes in the sahelo saharan area continental trade winds controlled the longshore drift in the northern part of the palaeolake two distinct lmc episodes dated as lower and middle holocene are clearly identified contemporaneous with the two phases of wetter conditions usually recognized in central and northern africa

seismotectonics and crustal stress field in the kumaon garhwal himalaya abstract we present fault plane solutions of 94 well located small to moderate sized 1 5 ml 5 4 earthquakes which occurred in the kumaon garhwal himalaya during 2005 2008 using p wave polarity and body wave amplitudes these earthquakes show a mixture of thrust normal and strike slip type mechanism with a majority of thrust type most of the thrust earthquakes occur at a depth of 8 22 km in the main central thrust mct zone and the lower himalaya the spatial distribution of these earthquakes suggest that the strain resulting from the ongoing collision of the indian plate with the eurasian plate is being consumed by thrust fault movement mainly on the north dipping munsiari thrust and south dipping tons thrust the strike slip earthquakes are mainly observed in the lower himalaya as well as around the munsiari region in the mct zone the normal earthquakes are also observed in different parts of the kumaon garhwal himalaya and the gangetic plain their occurrence is attributed to the local structure s as well as the flexure of the indian plate stress tensor inversion of the calculated fault plane solutions indicates that the maximum compressive stress in the gangetic plain is n s directed and near vertical whereas in the kumaon garhwal himalaya it is near horizontal and nne ssw directed and correlating with the prevailing stress condition due to northward movement of indian plate

high frequency holocene glacier fluctuations in the himalayan tibetan orogen abstract holocene glacial chronostratigraphies in glaciated valleys spread throughout the himalayan tibetan orogen including the himalaya tibet pamir and tian shan are developed using a landsystems approach detailed geomorphic mapping and new and published 10be surface exposure dating new studies in the kulti valley of lahul and the parkachik valley of the nun kun massif of the himalaya of northern india define three glacier advances at 14 7 12 2 0 5 ka in addition to one historically dated late 19th century advance in the kulti valley and one late holocene advance at 0 2 ka in the parkachik valley three major climatic groups subdivided into five climatic zones are defined across the orogen using cluster analysis ca and principal component analysis pca to identify glaciated regions with comparable climatic characteristics to evaluate the timing and extent of holocene glacier advances across these regions our regional analyses across the himalayan tibetan orogen suggest at least one lateglacial 15 3 11 8 ka and five himalayan tibetan holocene glacial stages hths at 11 5 9 5 8 8 7 7 7 0 3 2 2 3 1 0 and

a revised chronology for mississippi river subdeltas radiocarbon measurements by accelerator mass spectrometry relating to three of the four late holocene mississippi river subdeltas yielded consistent results and were found to differ by up to 2000 carbon 14 years from previously inferred ages these geological dataare in agreement with archaeological carbon 14 data and stratigraphic ages based on ceramic seriation and were used to develop a revised chronologic framework which has implications for prehistoric human settlement patterns coastal evolution and wetland loss and sequence stratigraphic interpretations

climate variability in the spanish pyrenees during the last 30 000 yr revealed by the el portalet sequence abstract palynological sedimentological and stable isotopic analyses of carbonates and organic matter performed on the el portalet sequence 1802 m a s l 42 48 00 n 0 23 52 w reflect the paleoclimatic evolution and vegetation history in the central western spanish pyrenees over the last 30 000 yr and provide a high resolution record for the late glacial period our results confirm previous observations that deglaciation occurred earlier in the pyrenees than in northern european and alpine sites and point to a glacial readvance from 22 500 to 18 000 cal yr bp coinciding with the global last glacial maximum the patterns shown by the new high resolution pollen data from this continental sequence chronologically constrained by 13 ams 14c dates seem to correlate with the rapid climate changes recorded in greenland ice cores during the last glacial interglacial transition abrupt events observed in northern latitudes heinrich events 3 to 1 oldest and older dryas stades intra allerod cold period and 8200 cal yr bp event were also identified for the first time in a lacustrine sequence from the central western pyrenees as cold and arid periods the coherent response of the vegetation and the lake system to abrupt climate changes implies an efficient translation of climate variability from the north atlantic to mid latitudes

use of alloformations for definition of holocene meander belts in the middle amite river southeastern louisiana geomorphological studies in drainage basins of the northern gulf of mexico coastal plain have indicated similarities in flood plain character and comparable influences on basin evolution alluvial morphology and stratigraphy can be linked to flood plain evolution through the use of alloformations unconformity bounded stratigraphic units this procedure extends classical terrace mapping concepts to conform with formally defined stratigraphic procedures a meander belt segment of the middle amite river valley in southeastern louisiana was selected to test the applicability of alloformation mapping in part of a regional scale 5 000 km 2 drainage basin three alloformations identified as magnolia bridge mag denham springs ds and watson wat can be differentiated by unconformable boundaries landscape morphology and relative pedogenic development the valley fill consists of a lower sandy and upper silty facies preserved deposits consist of channel lag point bar and scroll bar channel fill and overbank sequences lithofacies and sedimentary environments are dependent on fluvial process and a suite of meander belt environments can be identified within each alloformation surface horizons of alluvial soils are all similar ochric epipedons but subsoil horizons are chiefly stratified parent material on the mag entisols cambic horizons on the ds inceptisols and minimally developed argillic horizons on the wat alfisols allostratigraphy provides an objective method for definition of geologic units that contain genetically related but heterogeneous sedimentary deposits alluvial sediments are differentiated in a manner that successfully integrates geomorphic sedimentologic and pedologic data into significant stratigraphic models this approach is applicable to a wide variety of quaternary settings where prior stratigraphic techniques have resulted in ambiguity

glacial activity and catchment dynamics in northwest greece long term river behaviour and the slackwater sediment record for the last glacial to interglacial transition woodward j c hamlin r h b macklin m g hughes p d lewin j 2008 glacial activity and catchment dynamics in northwest greece long term river behaviour and the slackwater sediment record for the last glacial to interglacial transition geomorphology 101 1 2 44 67 sponsorship uk science and engineering research council woodward the school of geography at the university of leeds hamlin and the university of cambridge hughes the uk natural environment research council gr9 2916 and ip 754 0302 funded the bulk of the analyses reported here specialissue sp iss si

middle pleistocene glacier behaviour in the mediterranean sedimentological evidence from the pindus mountains greece detailed sedimentological analyses of diamicton sequences in two areas of the pindus mountains greece indicate multiple episodes of glacier advance and retreat during cold stages of the middle pleistocene these glacial sequences represent some of the most southerly in europe and are important archives of regional and global climate change the pindus glaciers were relatively small by world standards and would have been highly responsive to changes in air temperature and precipitation on mount tymphi at least three phases of glacier advance are recorded within deposits assigned to the skamnellian stage mis 12 further north on mount smolikas a thick multiple diamicton sequence records evidence for multiple glacier advances during both the skamnellian stage and the vlasian stage mis 6 these records highlight the dynamic nature of glacier behaviour in the mediterranean mountains during the middle pleistocene and provide new evidence for unstable cold stage climates

geomorphology and quaternary stratigraphy the roles of morpho litho and allostratigraphy abstract the subdivision and ordering of quaternary sediments and landforms is very often based on geomorphology quaternary landforms such as moraines river terraces palaeoshorelines and indeed any other landform can be arranged and ordered in time based on their relative position in the landscape morphostratigraphy is the subdivision of sedimentary units primarily on the basis of surface form whilst surface form is often used as a criterion for separating sedimentary units morphostratigraphy also usually incorporates lithological criteria to aid stratigraphical subdivision and morpho and lithostratigraphy are often interlinked in quaternary science however another approach allostratigraphy has increasingly been applied to subdivide and order quaternary sediment landforms allostratigraphy uses discontinuities to subdivide sedimentary successions allostratigraphy enables lateral variations in lithology to be included within the same stratigraphical unit furthermore it enables lithologically similar sediments stacked on top of each other to be divided into separate units based on discontinuities this paper examines the applications of morpho litho and allostratigraphy to subdivide sediment landform assemblages and critically reviews their role in quaternary stratigraphy

mountain glaciation and paleoclimate reconstruction in the picos de europa iberian peninsula sw europe abstract geomorphic mapping and stratigraphic analysis of a lake core document the late quaternary glacial history of the central and eastern massifs of the picos de europa northwestern spain the distribution of glacial deposits indicates that at their most advanced positions glaciers occupied 9 1 km2 extended as far as 7 km down valley and had an estimated equilibrium line altitude ela ranging between 1666 and 1722 m radiocarbon dating of sediment deposited in a lake dammed by moraines of this advance show that the maximum glacial extent was prior to 35 280 440 cal yr bp this advance was followed by two subsequent but less extensive late pleistocene advances recorded by multiple moraines flanking both massifs and sedimentary characteristics in the lake deposits the last recognized glacial episode is the 19th century maximum extent of small little ice age glaciers in the highest cirques above 2200 m

luminescence dating indicates radiocarbon age underestimation in late pleistocene fluvial deposits from eastern england robust geochronological control is crucial for interpreting and correlating the environmental record from fragmentary terrestrial sequences from the last glacial period traditional terrestrial stratigraphies are typically reliant on radiocarbon dating although estimates of antiquity for samples older than 40 ka may be unreliable optically stimulated luminescence osl dating of sediments is an alternative for dating the whole of the last glacial period and also provides the opportunity to independently test radiocarbon based chronologies this paper presents a set of nine directly comparable paired osl and accelerator mass spectrometry ams radiocarbon ages from multiple sites within devensian fluvial sediments in lowland britain and shows that it is possible to obtain robust osl age estimates throughout this time period the two techniques agree well for ages younger than ca 29 14c ka bp ca 35 cal ka bp but disagree beyond ca 35 14c ka bp ca 40 cal ka bp this is thought to be due to radiocarbon ages on older organic material having been contaminated by low levels of modern carbon it is therefore suggested that all conventionally pre treated radiocarbon ages greater than 35 14c ka bp should be treated with extreme caution copyright 2009 john wiley sons ltd

u series isochron dating of immature and mature calcretes as a basis for constructing quaternary landform chronologies for the sorbas basin southeast spain immature and mature calcretes from an alluvial terrace sequence in the sorbas basin southeast spain were dated by the u series isochron technique the immature horizons consistently produced statistically reliable ages of high precision the mature horizons typically produced statistically unreliable ages but because of linear trends in the dataset and low errors associated with each data point it was still possible to place a best fit isochron through the dataset to produce an age with low associated uncertainties it is however only possible to prove that these statistically unreliable ages have geochronological significance if multiple isochron ages are produced for a single site and if these multiple ages are stratigraphically consistent the geochronological significance of such ages can be further proven if at least one of the multiple ages is statistically reliable by using this technique to date calcretes that have formed during terrace aggradation and at the terrace surface after terrace abandonment it is possible not only to date the timing of terrace aggradation but also to constrain the age at which the river switched from aggradation to incision this approach therefore constrains the timing of changes in fluvial processes more reliably than any currently used geochronological procedure and is appropriate for dating terrace sequences in dryland regions worldwide wherever calcrete horizons are present

late glacial and holocene river development in the teleorman valley on the southern romanian plain this paper reports on a radiocarbon dated sequence of alluvial terraces from the tele orman valley in the southern romanian plain and represents the first late glacial and well constrained holocene alluvial sequence from the lower danube valley of southeast europe the two earliest and most extensive terraces t1 and t2 are dissected by large high amplitude palaeo channels which are dated to ca 12 800 yr bp and are comparable to large meandering palaeochan nels identified from other late glacial contexts across northern and central europe the remaining sequence of alluvial deposits show changes in river activity and accelerated sedimentation around 4900 4800 yr bp 4000 3800 yr bp 3300 2800 yr bp 1000 yr bp and within the past 200 yr a phase of tributary stream alluvial fan deposition is dated to ca 2400 yr bp all these periods of alluvial sedi mentation correlate well with episodes of climatic cooling higher rainfall and enhanced river activ ity both in terms of incision and greater lateral mobility as well as increased flood frequency and magnitude identified elsewhere in central western and northern europe human activity appears to have had little effect on this river environment and significant fine grained sedimentation is not noted until ca 2400 yr bp approximately 5000 yr after the first neolithic farmers settled the area whether this record of river activity truly reflects the impact of prehistoric societies on this catchment will only be elucidated through further ongoing detailed archaeological research copyright 2004 john wiley sons ltd

paleoenvironmental dynamics of low order paleovalleys in the late quaternary palmas cacador summit surface southern brazil abstract the quaternary dynamics of landscapes in the subtropical continental region of brazil is not still well understood pedostratigraphic records of low order paleovalleys paleovalley heads and 1st and 2nd order paleovalleys of the palmas cacador summit surface serve as important resources for the identification of landscape component responses relief soil sediment and vegetation of plateau areas of southern brazil in the light of environmental changes driven by climatic variations of the late quaternary we integrated litho pedo allo and chronostratigraphic descriptions with carbon stable isotope analysis phytoliths indices and 14c and osl dating we found that at 44 86 ky bp there was a change in the hydrodynamics of 2nd order perennial channels humid climate controlled possibly by tectonics at 28 35 to 23 69 to 28 ky bp regressive pedogenesis in dry climate began with a predominance of erosion by overland flows at 2 60 to 23 69 ky bp full regressive pedogenesis occurred under a continuous climate regime of drier characteristics punctuated by millenary climatic fluctuations to a wetter regime of between 4 60 and 19 77 ky bp echoing the results postulated by the knox s model during this period the most pronounced modifications to the landscape were made with a change in vegetation from campo cerrado to campo limpo with changes in erosion patterns caused first by overland flows and then earthflows debris flows and with the gradual silting filling and burying of gullies valley heads and 1st and 2nd order valley bases since 2 60 ky bp the area returned to a predominance of progressive pedogenesis in wet and cold climates finally we found that at the local scale low order basins

correlation of late quaternary moraines impact of climate variability glacier response and chronological resolution abstract the last decade has seen a global surge in the number and resolution of well dated geomorphological reconstructions of mountain glacier fluctuations and former ice sheet extents this has been facilitated by the widespread deployment of large samples of terrestrial cosmogenic nuclide dating tcnd allowing more sophisticated probability analyses for reducing the statistical uncertainty of moraine ages and testing of correlations at local regional and hemispheric scales geochronological advances in the field laboratory and on model calibration have taken place in parallel with modelling of palaeoclimate based on glacier reconstructions and of glacier sensitivity to temperature and precipitation forcing in spite of these advances basic conceptual issues remain this review questions whether the technical leap forward in dating has encouraged us to over reach our interpretive limits particularly in terms of the concept and practice of correlation we propose that to enable reliable correlation glacier chronologies should first be examined for their climatic integrity spatial coherence and chronological robustness even with excellent dating interpretive complexity remains due to complex climate signals and glacier response characteristics and to erosion censoring of the landform record all are issues which must be addressed to avoid either spurious lumping correlation or splitting differentiation of glacier chronologies and thus misinterpretation of the climatic significance of reconstructed glacier advances we suggest that the reliability of correlation is no better than the weakest link in the chain of reasoning which connects climatic fluctuations with dated landforms and sediments improved dating means that poor chronological resolution is less likely to be the limiting factor for correlation but shifts the focus onto other less quantifiable sources of uncertainty these conceptual statements are exemplified with reference to holocene glacial chronologies of contrasting mid latitude environments in southern norway iceland and new zealand

lithostratigraphy and age estimations of the pleistocene erosional remnants near the centre of the scandinavian glaciations in western finland abstract extensive 20 100 m thick quaternary sediment accumulations deposited before the latest weichselian stage were discovered in the suupohja region in western finland near the centre of the scandinavian glaciations fourteen lithofacies have been identified and interpreted in the accumulations geomorphologically and lithostratigraphically these accumulations occur in two forms 1 till covered beaded gravelly ridges that have occasional fine grained sediments and paleosols between the gravel and the overlying till and 2 irregularly shaped broad multilayer accumulations that include up to seven till units three silt clay units and three sand units these sediments have been deposited in glacial glaciofluvial glaciomarine lacustrine and possibly in littoral and eolian environments during up to six glacial deglacial cycles the units are divided into five formations which are proposed to form the suupohja group according to the luminescence datings lithostratigraphy and sedimentary structures the sediments below the uppermost till are interpreted to have been deposited before the latest weichselian glaciation which occurred during the middle or late weichselian substage this article clarifies the multiple lithostratigraphy of the suupohja region and introduces potential type sections for further stratigraphic studies the rich diversity of the sediments and their large extent makes this region one of the key areas in the pleistocene research of the glaciated areas of northern europe

three dimensional model of alluvial stratigraphy theory and applications abstract a three dimensional model of alluvial stratigraphy has been developed to simulate the spatial distribution proportion and connectedness of coarse grained channel belt deposits in alluvial strata as a function of channel belt width floodplain width bankfull channel depth channel belt and overbank sedimentation rates avulsion location and period compaction and tectonism tilting and faulting in this model a floodplain surface of variable width and length is occupied by a single channel belt changes in floodplain topography are produced by spatial and temporal variation of channel belt and floodplain deposition rates and by compaction and local or regional tectonism the location and timing of avulsions are determined by local changes in floodplain slope relative to channel b lt slope and by flood magnitude and frequency the diverted channel belt follows the locus of maximum floodplain slope at the end of each simulation architectural parameters are calculated including channel deposit proportion and connectedness and the dimensions of channel belt sandstone bodies three dimensional perspective diagrams mesh surfaces and two dimensional stratigraphic sections can be plotted to illustrate depositional surfaces time planes and the location and geometry of coarse grained channel belt deposits within finer grained overbank deposits the model predicts that channel belt proportion and connectedness and dimensions of sandstone bodies vary as a function of distance from avulsion points and cross section orientation upstream from avulsion points sandstone bodies have low width thickness ratios because of aggradation in a fixed channel belt immediately downstream from avulsion points channel belts tend to be connected resulting in sandstone bodies with high width thickness ratios avulsion sequences develop where points of avulsion shift up valley with a progressive decrease in avulsion period such sequences may produce successions in which channel belt proportion and connectedness vary vertically with a cyclic period of 103 to 105 years down valley increases in aggradation rate or down valley decreases in floodplain slope for example associated with a rise in base level may result in an increase in channel belt proportion and connectedness because of high avulsion frequencies in down valley regions of the floodplain down valley decreases in aggradation rate as in alluvial fans foreland basins and during base level fall may result in high avulsion frequencies in up valley parts of the floodplain tectonic tilting and faulting locally increase avulsion probabilities and channel belts generally shift toward areas of maximum subsidence under certain conditions however depositional topography may cause channels to shift away from areas of maximum subsidence channel deposit proportion and connectedness are gen rally high near downthrown areas of the floodplain but distribution clustering of channel belts may not be a reliable indicator of fault geometry or displacement models of alluvial architecture that consider only sediment accumulation rate as the main controlling factor are oversimplified the three dimensional model presented here predicts many of the features of channel behavior observed in modern rivers but there is a pressing need for better models and adequate natural data to test them

sequence stratigraphy of lacustrine deposits a quaternary example from the bonneville basin utah the late quaternary lacustrine sedimentary record in the bonneville lake basin in the eastern great basin provides an excellent example of sequence stratigraphy two sequences referred to as the little valley and bonneville alloformations are exposed in the bluffs of the sevier river where it has entrenched its pleistocene delta between leamington and delta utah both alloformations contain offshore marl units and fine grained deltaic or underflow fan deposits they can be identified and mapped by tracing the unconformity separating them and employing a number of geochronometric tools including amino acid epimerization in fossil gastropods radiocarbon and thorium 230 ages and basaltic tephrochronology thin transgressive sand of the little valley alloformation is overlain by deeper water marl and down lapping regressive phase deltaic silt the bonneville alloformation lies unconformably above the little valley deposits fine grained deltaic sediments deposited during the transgressive phase of lake bonneville fill the entrenched sevier river valley that was eroded subsequent to the little valley lake cycle marl deposited during the deep water phase is overlain by down lapping deposits of the regressive phase below the provo shoreline but is the uppermost unit in the altitudinal range where the lake was lowered catastrophically during the bonneville flood the sequence stratigraphic interpretation leads to the conclusion that the sevier river delta as a whole is probably made up of a number of sediment sequences each composed of several facies recognition of this complexity could be important in potential applications of the stratigraphic model

holocene paleolakes of lake canyon colorado plateau paleoclimate and landscape response from sedimentology and allostratigraphy middle and late holocene paleoclimate can be inferred from lake level fluctuations recorded in the sediment of two fresh groundwater controlled paleolakes in lake canyon southeast utah the record from lake canyon contributes proxy climate data for the region as well as insight into climate controls on sedimentation the paleolakes were formed immediately upcanyon of side stream confluences where disproportionately large volumes of alluvium were focused into the bedrock canyon excellent exposure allows a depositional facies model to be developed and allostratigraphic units to be defined a facies based proxy for the past shoreline position is applied to the allostratigraphy and radiocarbon based chronostratigraphy to produce a record of lake level through time that is corroborated by diatom proxy data the earliest known lake formed during an episode of aggradation that began just before 5180 14 c yr b p and an arroyo cutting event drained the lake before 3050 14 cy r b p the lake canyon record for the past 3 k y is composed of wet dry cycles that have a periodicity of 520 yr matching cycles resolved by the regional tree ring record and the timing of the medieval warm period and little ice age lake level rose after 420 14 c yr b p and aggradation continued until an advancing arroyo headcut drained the upper lake in a d 1915 fluvial and lacustrine aggradation in lake canyon accompanied shifts to wetter climate when sediment stored in upper reaches of the drainage basin was delivered to the canyon whereas arroyo cutting in the canyon is more a function of sediment supply and internal complex response mechanisms than dry climate conditions correlation with other records is hindered by differences in resolution and the influence of local controls on alluvial stratigraphy the lake canyon record confirms that episodes of high flood frequency in holocene time have been wetter overall but not all wet periods have been marked by high flood frequency

timing of pleistocene glaciations in the high atlas morocco new 10be and 36cl exposure ages abstract this paper presents data from 42 new samples yielding late pleistocene cosmogenic 10be and 36cl exposure ages of moraine boulders across a series of glaciated valleys in the toubkal massif 4167 m a s l high atlas morocco this represents the first comprehensive pleistocene glacial chronology in north africa and one of the largest datasets from the mediterranean region the timing of these glacier advances has major implications for understanding the influence of atlantic depressions on moisture supply to north africa and the mediterranean basin during the pleistocene the oldest and lowest moraines which span elevations from 1900 to 2400 m a s l indicate that the maximum glacier advance occurred from mis 5 to 3 with a combined mean 10be and 36cl age of 50 2 19 5 ka 1 sd n 12 7 outliers the next moraine units up valley at higher elevations 2200 2600 m a s l yielded exposure ages close to the global last glacial maximum lgm with a combined mean 10be and 36cl age of 22 0 4 9 ka 1 sd n 9 7 outliers the youngest exposure ages are from moraines that were emplaced during the younger dryas with a combined mean 10be and 36cl age of 12 3 0 9 ka 1 sd n 7 no outliers and are found in cirques at the highest elevations ranging from 2900 to 3300 m a s l from moraines predating the younger dryas a large number of young outliers are spread evenly between 6 and 13 ka suggesting a continuing process of exhumation or repositioning of boulders during the early to mid holocene this attests to active seismic processes and possibly intense erosion during this period

late glacial fluvial response of the niers rhine western germany to climate and vegetation change the niers valley was part of the rhine system that came into existence during the maximum saalian glaciation and was abandoned at the end of the weichselian the aim of the study was to explain the late pleniglacial and late glacial fluvial dynamics and to explore the external forcing factors climate change tectonics and sea level the sedimentary units have been investigated by large scale coring transects and detailed cross sections over abandoned channels the temporal fluvial development has been reconstructed by means of geomorphological relationships pollen analysis and 14c dating the niers rhine experienced a channel pattern change from braided via a transformational phase to meandering in the early late glacial this change in fluvial style is explained by climate amelioration at the late pleniglacial to late glacial transition at ca 12 5 k 14c yr bp and climate related hydrological lithological and vegetation changes a delayed fluvial response of ca 400 14c yr transitional phase was established the channel transformations are not related to tectonic effects and sea level changes successive river systems have similar gradients of ca 35 40 cm km 1 a meandering river system dominated the allerod and younger dryas periods the threshold towards braiding was not crossed during the younger dryas but increased aeolian activity has been observed on the younger dryas point bars the final abandonment of the niers rhine was dated shortly after the younger dryas to holocene transition traces of laacher see pumice have been found in the niers valley indicating that the niers rhine was still in use during the younger dryas copyright 2005 john wiley sons ltd

from cave geomorphology to palaeolithic human behaviour speleogenesis palaeoenvironmental changes and archaeological insight in the atxurra armina cave northern iberian peninsula

holocene alluvial morphopedosedimentary record and environmental changes in the bardenas reales natural park ne spain abstract a holocene alluvial morphostratigraphy based on geomorphological mapping sedimentological analysis soil development and radiocarbon chronology is presented for the semiarid blanca basin in the bardenas reales natural park ne spain four morphopedosedimentary alluvial units mu1 mu2 mu3 and mu4 were differentiated which may correspond to two palaeogeographical stages the first one includes the morphopedosedimentary unit mu1 and is the most extensive in the area it is made up of a complex aggradation fill up sequence comprising a braided channel system a sand mud flat 9200 7900 cal bp and a playa lake environment related to a nearly closed depression an intensive fluvial entrenchment period is recognized leading the opening of the blanca basin before the second stage that includes the units mu2 mu3 and mu4 this set of units forms a sequence of cut and fill and nested fill terraces recording the alluvial activity in the blanca basin during the last 6 ka the mu2 unit 5900 3300 cal bp in age represents a period of high geomorphic instability with rapid alluvial sedimentation channel incision oscillating changes on the other hand the mu3 unit has an age of 1050 500 cal bp and appears as a thin extensive alluvial cover overlying previous units finally the mu4 unit comprises superposition of numerous flood depositional sequences centimetric in scale dated from 450 10 cal bp the established soil chronosequence supports the numerical chronology of the four units these accumulation periods mu1 mu2 mu3 mu4 are associated with dry phases and or high hydrological variability floods and droughts at a regional scale changes on the north atlantic atmospheric circulation mode over southern europe may provide the key to explain the nature of alluvial activity during holocene in bardenas reales

sedimentology and allostratigraphy of post 240 ka to pre 26 5 ka lacustrine terraces at intracaldera lake rotorua taupo volcanic zone new zealand abstract lake rotorua partially occupies a nearly circular 20 km diameter volcano tectonic depression formed at c 240 ka by eruption of the voluminous mamaku ignimbrite three distinct lacustrine littoral terraces defined on the basis of contrasting geomorphology and field relations and separated by tephrostratigraphically dateable unconformities and basin floor disconformities fringe much of the lake basin they are here correlated with former high stands of the lake which resulted from the blockage and re establishment of a number of alternative outlets due to tectonic activity and volcanism at both the host and adjacent volcanic centres the unconformities allow division of the deposits into three allostratigraphic units each of which is then characterised by elevation and sediment provenance the

mass balance and equilibrium line altitudes of glaciers in high mountain environments abstract the mass balance characteristics of glaciers in high mountain environments complicate the relationship between glacier equilibrium line altitudes elas and climatic variables such as precipitation and air temperature therefore methods of ela reconstruction employed in low relief environments are commonly not applicable in high mountains or require some modification we review the concept of the ela with reference to the mass balance of a range of glacier types found in high mountain regions we examine the applicability of several commonly used methods of ela reconstruction for different glacier types and propose some general principles to guide the choice of appropriate methods

long term fluvial archives in nw france response of the seine and somme rivers to tectonic movements climatic variations and sea level changes the seine and the somme are the two main rivers flowing from northwestern france into the channel during the pleistocene cold stages both rivers were tributaries of the river manche which was exporting sediments into the central deeps of the channel the river seine has a very well developed terrace system recording incision that began at around 1 ma the same age is proposed for the beginning of the main incision in the somme valley on the basis of morphostratigraphy pedostratigraphy palaeontology palaeomagnetism and esr datings the uplift rate deduced from analysis of the seine and somme terrace systems is of 55 to 60 m ma since the end of the lower pleistocene the response of the two rivers to climatic variations uplift and sea level changes is complex and variable in the different parts of the river courses for example the evolution of the lower seine system is influenced by uplift and climate changes but dominated by sea level changes in the middle seine the system is beyond the impact of sea level variations and shows a very detailed response to climatic variations during the middle and upper pleistocene in a context of uplift the somme valley response appears to be more homogeneous especially in the middle valley where the terrace system shows a regular pattern in which incision occurs at the beginning of each glacial period against a general background of uplift nevertheless the lower somme valley and the palaeo somme in the channel area indicate some strong differences compared with the middle valley influence of sea level variations and probably differences in rates of tectonic uplift between the channel and the present continent the differences in the responses of the two river valleys during the pleistocene are related to differences in the size of the fluvial basins to the local tectonic characteristics to the geometry of the platform connected to the lower parts of the valleys and to the hydrodynamic characteristics of each river finally it is shown from these examples that the multidisciplinary study of pleistocene rivers is a very efficient tool for the investigation of neotectonic activity

the glacial history of the pindus mountains greece abstract geomorphological evidence for pleistocene glaciation has been mapped in the pindus mountains of northwest greece and the chronology of glaciation in this area has been established through soil profile analysis and u series dating of secondary carbonates calcite formed within glacial deposits three glacial stages are evident in the sedimentological and geomorphological records the earliest and most extensive recorded glaciation predates 350 000 yr b p and was characterized by extensive valley glaciers and ice fields a more recent glaciation occurred before the last interglacial and was characterized by glaciers that reached midvalley positions the last phase of glaciation in greece is recorded by small cirque glacier moraines and relict periglacial rock glaciers the glacial and periglacial sequence on mount tymphi has been used in conjunction with a reference parastratotype the long lacustrine sequence at ioannina to provide a chronostratigraphical framework for cold stage deposits in g

the late archean to mesoproterozoic major unconformity bounded units of the kaapvaal province of southern africa reply abstract the late archean to mesoproterozoic 3 1 1 4 ga sedimentary and volcanic successions in the kaapvaal province of southern africa previously have been subdivided into numerous lithostratigraphic units that generally were believed to have been deposited in local or regional basins however these lithostratigraphic units are remnants of thirteen unconformity bounded sequences or units 10 3 m thick with composite strike lengths of 250 1100 km and with durations of 10 7 to 10 8 yr all of these units rest somewhere on the crystalline basement the stratotypes but not the full geographic extents of these sequences from the base upward are the dominion group west rand group of the witwatersrand supergroup central rand group of the witwatersrand supergroup klipriviersberg group of the ventersdorp supergroup platberg group of the ventersdorp supergroup pniel group of the ventersdorp supergroup black reef quartzite formation and chuniespoort group of the transvaal supergroup pretoria group of the transvaal supergroup and the interval represented by the dullstroom formation rooiberg group and the loskop formation three or more major unconformity bounded units occur in younger proterozoic rocks in the kaapvaal province but are not definitive of it two occur in the soutpansberg group and one is most of the waterberg group some of these unconformity bounded units are remarkably similar to phanerozoic cratonic and miogeoclinal sequences they are the natural building blocks for reconstructing archean and proterozoic depositional basins plate tectonic events continents and a provincial time scale

the middle pleistocene glacial evolution of northern east anglia uk a dynamic tectonostratigraphic parasequence approach the middle pleistocene glacial history of northern east anglia is a controversial topic with differing opinions surrounding chronology provenance and the relative stratigraphic framework reconciling the stratigraphic framework of the region is an essential first step to developing onshore offshore geological models and a robust event driven chronological framework within this study a dynamic tectonostratigraphic parasequence methodology is applied to deposits traditionally attributed to the anglian glaciation marine isotope stage 12 this approach offers an insight into ice bed coupling during glaciation and how evolving boundary conditions influenced glacier dynamics six major tectonostratigraphic parasequence assemblages a1 a6 are recognized in northern east anglia and correlate with successive advances into the region of north sea or pennine lobes of the british ice sheet individual tectonostratigraphic parasequence assemblages are bound at their base by a sedimentary contact or more commonly a glacitectonic zone the geometry and structural characteristics of these glacitectonic zones reflect temporal and spatial variations in ice bed coupling traction a function of substrate rheology and in turn variations in lithology porewater availability and thermo mechanical properties the role of permafrost may also be significant promoting proglacial ice marginal thrust stacking in front of advancing ice and enhanced ice bed decoupling during subsequent overriding and subglacial till accretion 2016 british geological survey nerc journal of quaternary science 2016 john wiley sons ltd

combining allostratigraphic and lithostratigraphic perspectives to compile subregional records of fluvial responsiveness the case of the sustainably entrenching palancia river watershed mediterranean coast ne spain abstract we use a combined allostratigraphic and morpholithostratigraphic approach to establish a relative stratigraphy of macroscale sediment landform units in the mediterranean palancia river watershed 986 km2 ne spain four alloformations signifying important changes in sub regional scale geomorphic valley floor evolution were identified based on data from 1120 field sites and age determinations and from analyzing high resolution geodata the formation of the widespread and thick pleistocene alloformation can be attributed to climatically induced excessive sediment supply and flood activities during pleistocene cold intervals rather than representing time lagging response to plio pleistocene neotectonic uplift triggered by the turn to holocene climatic conditions three successively inset alloformations illustrate how stream grading and floodplain narrowing continuously have progressed over the holocene the overall degradational valley floor evolution in the holocene is interpreted as a response to the antecedent overly valley floor aggradation allostratigraphic and morphostratigraphic data suggest that the abandonment of the two earlier holocene alloformations geomorphologically represents a pulsed turn toward intensified entrenchment rather than pulsed sedimentation the most important benefit of amalgamating allostratigraphic and morpho lithostratigraphic concepts is that allostratigraphic ordering provides a formally conclusive approach to scale up morpho lithostratigraphic information from the reach scale to much larger scales of geographical extent consequently applying allostratigraphic principles opens a perspective to moving forward toward analyzing the relationships between climate neotectonics sea level change human impact and fluvial response in coupled hinterland coastal systems that require to evaluate sedimentary information at larger spatial scales

research history on glacial geomorphology and geochronology of the cantabrian mountains north iberia 43 42 n 7 2 w abstract the study of glacial geomorphology in the cantabrian mountains a mountain range that extends 460 km along the northern coast of the iberian peninsula sw europe started late in the 19th century and continues nowadays with a growing number of research papers however the number and timing of glaciations remains poorly understood partially due to the still limited number of numerical ages its southerly location and proximity to the atlantic ocean make this mountain range potentially sensitive to past climate fluctuations this work updates the glacial knowledge evolution for the whole range from the queixa invernadoiro massif to the basque mountains reviewing i the history of glacial research since the late 19th century ii the methodological approaches applied to reconstruct both the spatial extent and timing of past glacial stages and iii the main geomorphological and geochronological evidence reported until date including glacial features attributed to the last glacial cycle last 120 ka and previous glaciations according to current knowledge glaciers extended over the cantabrian mountains covering a total area of 3150 km2 showing asymmetric development conditioned by variations of the topographic configuration and moisture supply along the range available geochronology based on radiocarbon optically stimulated luminescence and terrestrial cosmogenic nuclides suggests the occurrence of at least 2 glacial advances during the last glacial cycle i a glacial maximum stage that took place at a minimum age of 36 45 ka marine isotope stage 3 and ii a second glacial advance at 19 23 ka mis 2 in some areas the extent of the glacier tongues during the second glacial advance was comparable to previous glacial maximum and was followed by glacial retreat conditions with formation of recessional moraines asynchronous glacial maximum conditions have been reported only for the castro valnera mis 4 3 numerical ages and queixa invernadoiro mis 6 1 numerical age massifs until now finally geomorphological evidence reported in picos de europa has been attributed to prior glaciations and correlated to cold conditions recorded during mis 12 and mis 22 based on a very limited number of numerical ages

glacial stratigraphy of stough creek basin wind river range wyoming abstract multiparameter relative age ra techniques identify four post pinedale morphostratigraphic units in each of three cirque valleys tributary to stough creek basin wind river range wy soil development lichenometry boulder weathering characteristics and the geomorphic relations among morphostratigraphic units indicate glacial deposits here correspond to the sequence previously described in the temple lake valley arct alp res 6 1974 301 cirque deposits in stough creek basin correspond to the temple lake alice lake black joe and gannett peak alloformations gsa abs prog 32 2000 a 16 10 be ages from moraine boulders and polished striated bedrock assoc am geogr annu mtg abs 2000 155 support recent numeric age estimates from temple lake and titcomb basin that indicate the temple lake alloformation corresponds to the younger dryas climate episode geogr phys quat 41 1987 397 geology 23 1995 877 science 268 1995 1329 gsa abs prog 31 1999 a 56 soils described from pinedale recessional deposits here represent the first systematic description of pinedale alpine deposits in the wrr

sedimentation close to the active medlicott wadia thrust western himalaya how to estimate climatic base level changes and tectonics the medlicott wadia thrust mwt is one of the major active out of sequence thrusts in the himalaya studies on quaternary terraces in its vicinity have been performed using sedimentological geomorphic and geochronological methods we focus on the riasi zone south of the pir panjal range in the jammu and kashmir region of india the sedimentary units of quaternary landforms have been mapped as a function of their location with respect to the thrust faults their relative chronology and their lithology three aggrading sedimentary units five thin units above strath surfaces at the footwall of the fault system and seven thin units above strath surfaces at its hangingwall are identified the terraces have been dated by combining optically stimulated luminescence osl on fine grained deposits and cosmogenic nuclide dating 10be on sandstone pebbles sampled along depth profiles throughout the alluvial units three major allostratigraphic units were defined with upper surface ages estimated at 4 15 and 36 3 ka the two older allostratigraphic units are encased terraces at the hangingwall but superposed sedimentary units at the footwall they are related to phases of elevation of the river level respectively 30 and 60 m at 36 38 and 14 15 ka and to a phase of extensive lateral incision before 4 ka these units present vertical offsets induced by the mwt of 50 190 and 375 m respectively by taking the aggradation incision rates at the footwall of the mwt into account we found that the uplift of the hangingwall remains uniform since 36 ka with a value of 10 mm yr therefore the aggradation incision events observed in the riasi area cannot be ascribed to variations in the tectonic rates and are most likely driven by climatic fluctuations the high uplift rate is possibly local and related to the chenab recess which affects the himalayan frontal structure our results indicate that the mwt is an active growth fault and one of the main emergences of the active indian asian plate boundary in western himalaya

late quaternary fluvial sedimentation in the voidomatis basin epirus northwest greece abstract detailed morpho and lithostratigraphic investigations allied with radiometric dating in the voidomatis basin epirus northwest greece have identified four quaternary terraced alluvial fills that range from middle pleistocene to historic in age major periods of alluviation during the late quaternary were associated with valley glaciation ca 26 000 20 000 yr b p and subsequent deglaciation ca 20 000 15 000 yr b p in the pindus mountains during late wurmian times and more recently linked to overgrazing sometime before the 11th century ad the late quaternary alluvial stratigraphy of the voidomatis river is more complex than the older fill and younger fill model outlined previously and it is suggested that these terms should no longer form the basis for defining alluvial stratigraphic units in the mediterranean basin

quaternary glaciation of muztag ata and kongur shan evidence for glacier response to rapid climate changes throughout the late glacial and holocene in westernmost tibet the glacial geology of two massifs muztag ata and kongur shan in western tibet was examined to help define the timing and style of glaciation in the semiarid regions of western tibet remote sensing geomorphic mapping and 10be terrestrial cosmogenic nuclide tcn surface exposure dating of boulders on the moraines and sediment in depth profiles show that glaciers advanced at least 12 times during at least the last two glacial cycles over this time the style of glaciation changed progressively from one that produced ice caps to one that produced less extensive and more deeply entrenched valley glaciers the timing of the two earliest glaciations is poorly defined but they likely occurred prior to the penultimate glacial cycle the karasu glacial stage and the early part of the last glacial cycle or during the penultimate glacial cycle the subaxh glacial stage in contrast the timing of later glacial advances the olimde glacial stage is relatively well defined showing quasiperiodical oscillations on millennial time scales 17 1 0 3 ka 13 7 0 5 ka 11 2 0 1 ka 10 2 0 3 ka 8 4 0 4 ka 6 7 0 2 ka 4 2 0 3 ka 3 3 0 6 ka 1 4 0 1 ka and a few hundred years before the present these data suggest that since the global last glacial maximum lgm the glaciers in western tibet likely responded to northern hemisphere climate oscillations rapid climate changes with minor influences from the south asian monsoon this study provides the first well defined glacial geologic evidence to suggest that glaciers in western tibet respond to rapid climate changes on millennial time scales throughout the late glacial and holocene

quaternary history and landscape evolution of a high altitude intermountain basin at the western end of the himalayan tibetan orogen waqia valley chinese pamir abstract quaternary valley fills and landforms in the waqia valley of the chinese pamir were examined using geomorphic mapping geomorphic and sedimentological analysis of landforms and sediments and cosmogenic 10be surface exposure dating six sets of moraines m 1 to m 6 are identified and date to the penultimate or an older glacial cycle m 1 penultimate glacial cycle m 2 early last glacial and probably marine oxygen isotope stage mis 4 m 3 mis 2 m 4 late glacial m 5 and early holocene m 6 younger moraines are also present but these were not examined in detail alluvial fans and outwash river terraces are present throughout the valley four surfaces on alluvial fans and river terraces were dated to 580 ka t 1 120 ka t 2 100 ka t 3 and 70 ka t 4 large landslide and lacustrine deposits are common within the valley fills and represent periods of major slope instability and possible damming of drainages glacial processes dominate the western side of the valley landsliding is the leading process on its eastern side defining the nature and timing of landform formation in this valley highlights the punctuated nature of landform evolution in the himalaya and tibet and provides a framework for considering the abundant valley fill successions elsewhere in the orogen

quaternary glacial evolution in the central cantabrian mountains northern spain abstract the glacial evolution of the cantabrian mountains is not well known previous studies have focused on the extent of the glacial maximum and the presence of younger features in several massifs recently efforts have been made to date glacial periods particularly the glacial maximum this work presents a reconstruction of the glacial evolution in the cantabrian mountains providing data on the environmental characteristics and timing of the different stages from the quaternary glacial maximum to the little ice age the study area covers 3000 km 2 between the 4 58 w and 3 34 w and includes eleven massifs of the central area of the cantabrian mountains the selected sectors have an atlantic and atlantic mediterranean transitional climate and include the highest massifs above 2600 m and low altitude glacierised massifs lower than 2000 m glacial extent and evolution have been reconstructed on the basis of detailed geomorphological and morphostratigraphic mapping the equilibrium line altitude palaeo ela has been estimated for the different stages of each tongue the ela has been assessed by the aar and modified kurowski methods and altitude methods have been considered a numerical chronological framework is proposed using 17 ams radiocarbon and one osl data obtained in lake and bog deposits from three massifs four main glacial stages have been differentiated between 38 000 bp and the little ice age they correspond to different cold environments and the number of glacial stages varies from one to four among the different massifs conclusions are analysed in the context of the quaternary glacial evolution of other iberian mountains

the glacial history of the dinaric alps montenegro abstract large areas of montenegro were glaciated during the pleistocene this paper presents evidence from the massifs of central montenegro including durmitor and sinjajevina moracke planine maganik prekornica and vojnik glacial deposits have been subdivided on the basis of morphostratigraphy and soil weathering and 31 u series ages from cemented tills provided a geochronological framework the largest glaciation occurred before 350 ka when a series of conjoined ice caps over the massifs of central montenegro covered a total area of nearly 1500 km 2 these formed during mis 12 and correspond with the largest skamnellian stage glaciations in greece to the south later middle pleistocene glaciations occurred during the penultimate glacial cycle correlating with the vlasian stage in greece mis 6 when ice caps covered an area of 720 km 2 over central montenegro there is also geochronological evidence of glacial deposits dating from the interval between mis 12 and mis 6 before the interglacial complex of mis 7 this glaciation appears to have been very similar in extent to that which occurred during mis 6 the last glacial cycle in central montenegro was characterised by valley and cirque glaciers covering a total area of 49 km 2 it is very likely that glaciers have been present in the mountains of central montenegro during every glacial cycle since a small glacier still survives today the smaller glaciers of the last glacial cycle are likely to have been associated with summer temperatures that were warmer than those of earlier cold stages the striking contrast in the extent and thickness of ice cover during the cold stages of the pleistocene has an important bearing on the geomorphological and biological evolution of the balkans

how global are the jurassic cretaceous unconformities the reality of the global scale sedimentation breaks remains controversial a compilation of data on the jurassic cretaceous unconformities in a number of regions with different tectonic settings and character of sedimentation where new or updated stratigraphic frameworks are established permits their correlation unconformities from three large reference regions including north america the gulf of mexico and western europe were also considered the unconformities which encompass the jurassic cretaceous the lower upper cretaceous and the cretaceous palaeogene transitions are of global extent other remarkable unconformities traced within many regions at the base of the jurassic and at the santonian campanian transition are not known from reference regions a correlation of the jurassic cretaceous global scale sedimentation breaks and eustatic curves is quite uncertain therefore definition of global sequences will not be possible until eustatic changes are clarified activity of mantle plumes is among the likely causes of the documented unconformities

the timing and extent of quaternary glaciation of stok northern zanskar range transhimalaya of northern india abstract the glacial history of three tributary valleys namlung gopal kangri and stok kangri of the stok valley south of the indus valley in the northern sector of the zanskar range northern india is characterized using geomorphic mapping and cosmogenic 10be surface exposure dating the new glacial chronostratigraphy for the stok valley is the first for the northern zanskar range and provides insights into the spatial variability of glaciation in the himalayan tibetan orogen this framework facilitates the understanding of the nature and the timing of landscape evolution and paleoenvironmental change in the himalayan tibetan orogen at least four glacial stages are evident within each of the tributary valleys of gopal kangri mg1 mg4 youngest to oldest and stok kangri ms1 ms4 that feed into the stok valley with the exception of the mg4 glacial advance 124 ka in gopal kangri the stok valley has preserved evidence of glaciations from 50 ka to the present equilibrium line altitudes and glacier reconstructions for the stok valley and its tributaries demonstrate that glaciations have become progressively less extensive through time former glacier extents of the stok region are comparable in length with glacial advances during the last glacial cycle in eastern zanskar and in the southern ladakh range to the south and north of the indus valley respectively landscape evolution in the study area has occurred across numerous glacial interglacial cycles by a combination of glacial and fluvial processes and is similar to that of the ladakh range

pleistocene ice caps on the coastal mountains of the adriatic sea ice caps once covered large areas of mount orjen 1894 m on the adriatic coast of montenegro bosnia herzegovina croatia the largest ice cap covered an area of c 165 km2 and reached a maximum ice thickness of c 450 m in some areas reaching down to 500 m above modern sea level u series dating of secondary carbonates within moraines indicates that the most extensive glaciation occurred during the middle pleistocene correlating with a major phase of glaciation in greece to the south during mis 12 c 480 430 ka later less extensive glaciations are also recorded in the cirques and valleys and correlate with glaciations during mis 6 190 130 ka and mis 5d 2 110 11 7 ka each phase of glaciation would have required large amounts of snow accumulation under modern precipitation values which at c 5000 mm are some of the highest in europe mean annual temperatures would need to be only c 5 6 c lower in order to form similar sized glaciers today a mean annual temperature depression of 12 13 c would still require 1000 mm of snow accumulation water equivalent to balance ablation suggesting sustained moisture supply during pleistocene cold stages such sustained precipitation supply during pleistocene cold stages is likely to have been facilitated by major temperature contrasts between the european landmass and the mediterranean sea which are likely to have sustained lee side vortices to the south of the alps in the gulf of genoa and adriatic sea forming weak moisture bearing depressions which tracked across the eastern adriatic coastal mountains large ice caps on the dinaric alps would have blocked the inland penetration of these depressions resulting in much drier conditions in the balkan interior creating favourable conditions for the deposition of thick accumulations of loess the last glaciers on orjen formed during the younger dryas 12 9 11 7 ka and confirm the influence of north atlantic ocean circulation on pleistocene climate change in this part of the mediterranean

late pleistocene and late holocene lake highstands in the pyramid lake subbasin of lake lahontan nevada usa shoreline geomorphology shoreline stratigraphy and radiocarbon dates of organic material incorporated in constructional beach ridges record large lakes during the late pleistocene and late holocene in the pyramid lake subbasin of lake lahontan nevada usa during the late holocene a transgression began at or after 3595 35 14 c yr b p and continued perhaps in pulses through 2635 40 14 c yr b p resulting in a lake as high as 1199 m during the latest pleistocene and overlapping with the earliest part of the younger dryas interval a lake stood at approximately 1212 m at 10 820 35 14 c yr b p and a geomorphically and stratigraphically distinct suite of constructional shorelines associated with this lake can be traced to 1230 m these two lake highstands correspond to periods of elevated regional wetness in the western basin and range that are not clearly represented in existing northern sierra nevada climate proxy records

a new quaternary stratigraphy of the kallang river basin singapore implications for urban development and geotechnical engineering in singapore abstract the quaternary stratigraphy of many coastal areas in southeast asia is poorly understood developing a detailed framework is important as many coastal cities are built on these unconsolidated coastal marine sediments this study reviews the current understanding of quaternary deposits in the kallang river basin singapore using 161 boreholes to create 14 cross sections and a 3d geological model the dataset is augmented with a 38 5 m long sediment core obtained from marina south 1 2726 n 103 8653 e and a previous record from geylang 1 3137 n 103 8917 e to provide age constraints and stratigraphic reference a new quaternary stratigraphic framework for singapore is presented here constrained by new radiocarbon and optically stimulated luminescence osl dating and identify palaeo features that record the geomorphic and sedimentary evolution of the basin fluvial deposits of pleistocene age are uncomfortably overlain by littoral tidal sands and subsequently marine clay possibly during marine isotope stage mis 5e 125 ka bp subsequent subaerial exposure and weathering of the marine clay during the last interglacial produced a stiff clay layer the stiff clay is unconformably overlain by holocene transgressive sands and peats from 9 5 ka bp followed by marine clays with a maximum basal age of 9 2 ka bp regressive sandy peat units were subsequently deposited beginning 6 ka bp here the new quaternary stratigraphic framework for singapore is presented as well as provide important constraints on the regional sea level history and geomorphological evolution of singapore s southern coast from mis 5e to present the work also highlights the complexities of geoengineering work in such subsurface terranes