Quaternary Map Research Articles

Quaternary Map, Active Faulting, Tectonic Geomorphology, and Uplift Rate of the Humboldt Range in the Basin and Range Province of Nevada, United States

ABSTRACT Fault-truncated, uplifted, and abandoned alluvial fans are frequent along the western flank of the active normal fault bounded Humboldt range. Terrestrial cosmogenic nuclide surface exposure dating of a faulted terrace at Rocky Canyon indicates that uplift of the range has averaged about 0.12 mm/yr during the last ∼160 ka. A similar uplift rate of less than about 0.07 mm/yr over the last 35 ka or more years is estimated from offset of a younger terrace at the same site. Values of extension rate across the range are 0.04–0.07 mm/yr, if it is assumed that the range-bounding fault dips at 60°, in general accord with very low values of contemporary geodetic strain reported for the area. Geomorphology at Rocky Canyon records a period leading up to about 160 ka ago that erosion and aggradation of sediment along the rangefront were dominant over fault generated uplift, at which time faulting again became dominant, leading to uplift, incision, and preservation of ∼160-ka-old alluvial terraces here and elsewhere along the rangefront.

Assessment of the Amaruq gold deposit signature in glacial sediments using multivariate geochemical data analysis and indicator minerals

The varying nature and thickness of glacial sediments affect the characteristics of mineralized dispersal trains in the Amaruq gold deposit area in Nunavut, northern Canada. To help evaluate the deposit signature, glacial sediments were collected from frost boils along transects parallel to the main ice-flow direction. A complementary detailed geochemical drift exploration dataset and a new Quaternary map were also used to define and interpret the geometry of the mineralized debris dispersal trains. Principal Component Analysis identifies a gold mineralization signature associating As, Ag, Au, Cu, Pb, Sb, W, S, Fe, and Zn and its mafic-BIF (Banded Iron Formation) host rock. This signature, similar to other lode gold geochemical signatures, follows a general NNW dispersal trend, in agreement with the predominant regional and local ice-flow indicators. In a zone characterized by streamlined landforms composed of thick distally -derived till, the dispersal train shows a higher distance for the first indicator to appear at surface down-ice of the known mineralization (~1 km lag) when compared to other mineralized dispersal trains (~300 m lag). Results from this area also show a lower intensity of deposit signature compared to mineralized dispersal trains located in thin locally-derived till characterized by small transverse moraine ridges. Elevated counts of scheelite and pristine-shaped gold grains are found down-ice of mineralization and their distribution is in general agreement with the dispersal train patterns defined by the till-matrix geochemistry. Our results strengthen the use of PCA and indicator minerals combined with an understanding of ice flow dynamics to map deposit signatures at surface and efficiently guide mineral exploration during glacial sediment surveys at local scales.

Loessoids of Russia: Varieties and distribution

This review serves as an explanatory note to the sketch map of loessoids, i.e. loess and various loess-like deposits. The map is a byproduct of the ongoing project of Quaternary Map of the Russian Federation, scale 1:2,500,000 in GIS-format. The primary information is derived from the standard National Geological Map scale 1:1,000,000 of the last two generations supplemented by literary data. The map polygons present all mappable loessoid units, including thick southern carbonate loess with paleosols, loess-like silts of northern terrains, intercalations of loessic sediments with waterlain facies and icy silts of the Arctic and Subarctic type. The loessoid formations are classified according to their stratigraphic intervals: 1) the radiocarbon dated Upper Pleistocene of northern terrains, 2) the Middle plus Upper Pleistocene of central Russia, 3) the late Lower Pleistocene to Upper Pleistocene series of southern regions and 4) the Lower Pleistocene red clays of the south. The distribution of diverse loessoids is an imprint of: i) the diverse sedimentary environments of the basically arid periglacial zones of the Pleistocene and ii) the modern geographical zonality changing from subtropics to the icy High Arctic and responsible for post-depositional alteration of subaerial dust. Whatever the origin of the primary dust and geographical varieties of the diagenesis, all loessoids share the same fundamental feature – paleosols, whether numerous and expressive or scarce and weak. They underline the climatically driven intermittent process of loessoid formation – basically subaerial and independent of any aqueous agencies.

Seismic Site Condition of Mainland China from Geology

AbstractWe use geology as a proxy to produce a site condition map of mainland China for seismic hazard assessment. The geology is from a 1:1,000,000-scale digital database and a 1:2,500,000-scale Quaternary map. We use the lithological descriptions and ages to assign the site condition for each geologic unit. Published site condition data are used to evaluate our mapping results. Our results agree well for the strong-motion stations in Gansu–Sichuan area, except in the mountainous area. There, the mismatches are due to our geological map scales missing narrow river terrace deposits. Our results also match well in the Shandong and Beijing Plain areas, except in thin fluvial and alluvial deposits fringing bedrock mountains. Our site-response categories match well-published average VS–depth profiles from microzonation studies of 14 major urban areas.

Sergei Yakovlev (1878–1957) – the founder of the scientific school of quaternary mapping and quaternary studies in Leningrad

Показана научная, педагогическая и организационная работа профессора С.А. Яковлева в области изучения четвертичной системы. Он был первым учёным секретарём Комиссии по изучению четвертичного периода (1927– 1936). Руководил отделом четвертичной геологии ВСЕГЕИ, избран генеральным секретарём редакционной комиссии международной карты четвертичных отложений по восточной части Европы (1932), входил в президиум и стал вице-президентом Советской секции INQUA. Организатор экспедиций по исследованиям четвертичного периода, автор и редактор многочисленных научных публикаций. Внёс большой вклад в составление и редактирование первых карт четвертичных отложений Европы и Западной Сибири. Professor Sergey Aleksandrovich Yakovlev is described in his scientific, pedagogical and organizational activities in the study of the Quaternary. He was the first scientific-secretary of the Commission for Study of the Quaternary (1927–1936). He was the head of the Quaternary Geology Department in All-Union Scientific Research Geological Institute (VSEGEI) in Leningrad. Secretary General of the Editorial Commission of the International Map of Quaternaries for Eastern Europe (1932). He later became vice-president of the Soviet section of INQUA (1941). Yakovlev made a great contribution to the compilation and editing of the first maps of Quaternary deposits of Europe and West Siberia. He was organizer of the Quaternary research in the USSR, author and editor of numerous scientific publications.

The Quaternary landforms of the Büyük Menderes Graben System: the southern Menderes Massif, western Anatolia, Turkey

ABSTRACT We present the first detailed Quaternary landform map of the Büyük Menderes Graben System, located in western Turkey which is one of the most active extensional domains in the world. The main map was produced with a combination of TanDEM-X (12.5 m resolution), Red Relief Image Map, unmanned aerial vehicle, Google Earth images, and multiple fieldworks. The main map is presented at a scale of 1:160,000 although landforms were mapped at a scale of 1:15,000. The ten Quaternary landforms were defined considering their surface morphology and depositional environment. The alluvial fans, river terraces, and floodplains are the most common landforms. The spatial pattern of the alluvial fans and river terraces showed the variable rates of tectonics and surface processes along the strike of the graben system. The distribution of the meander cut-offs and paleo-shorelines imply that Büyük Menderes Graben System is vulnerable to geohazards like flash-flood sedimentation and flood events.

Voltage Mode Multiple Valued Analog to Quaternary Mapping

Most of the digital processing is performed in the binary domain. With the increasing integration, chip area became an important resource to improve transistor density and energy efficiency. An alternative to reduce chip area is to increase the representation up to base B, domain D: (0, 1, 2,..., B - 1) known as Multiple-Valued Logic (MVL) to decrease chip wirings due to the fact that approximately 70% chip area is devoted to the interconnections. For the digital processing of analog signals an Analog to Digital Mapping is needed. This proposal is a mapping and not a complete analog to digital converter (ADC) due to the fact that there are not any circuits to correct errors, for example: linearity, bits synchronization, etc. This work presents a voltage mode multiple valued analog to quaternary mapping architecture for two digits utilizing the chosen universal set of MVL operators presented in the literature for quaternary base B=4:eAND1, eAND2, eAND3, Successor, and Maximum that allows to design any MVL digital circuit. Simulations on Cadence Tools for the AMS CMOS 0,35 μm technology will be presented to demonstrate concepts and circuit feasibility and functionality, showing correct behavior with respect to the specification and compatibility with the chosen universal set of gates.

Geological mapping for the urban area of Tarragona

A detailed and systematic geological characterization of the urban area of Tarragona has been conducted under the project ‘1:5000 scale Urban geological map of Catalonia’ of the Institut Cartografic i Geologic de Catalunya. The results of this characterization are organized into: (1) a geological information system that includes all the information acquired; (2) a geological model focused on the identification, characterization and correlation of the geological materials and structures that are present in the area, and (3) a detailed geological map that represents the synthesis of all the collected information. The mapping project integrates in a GIS environment pre-existing cartographic documentation (geological and topographical), core data from compiled boreholes, descriptions of geological outcrops within the urban network and neighbouring areas, physico-chemical characterization of representative samples of geological materials, detailed geological mapping of Quaternary sediments, subsurface bedrock and artificial deposits, and 3D modelling of the main geological surfaces. The geological model is structured in a system of geological units that form a chronostratigraphic point of view are structured in Preneogene (from Mesozoic to Paleogene), Neogene, Quaternary and Anthropocene. The description of the geological units is guided by a systematic procedure. It includes the main lithological and structural features of the units that constitute the geological substratum and represents the conceptual base of the published map sheets of the urban geological map of the Tarragona metropolitan area. These map sheets are composed of a principal map, geological cross sections, and several complementary maps, charts and tables. Regardless of the geological map units, the principal map also represents the main artificial deposits, features related to the geohistorical processes, contours of outcrop areas, information obtained in stations, borehole data, and contour lines of the top of the pre-quaternary basement surface. The most representative complementary maps are the Quaternary map, the subsurface bedrock map, and the isopach map of thickness of superficial and anthropogenic deposits. The map also includes charts and tables of relevant physico-chemical parameters of the geological materials, harmonized downhole lithological columns from selected boreholes, stratigraphic columns, and photographs and figures illustrating the geology of the mapped area and how urbanization has changed the natural environment. The development of systematic urban geological mapping projects, such as the example of Tarragona’s case, which provides valuable resources to address targeted studies related to urban planning, geoengineering works, soil pollution and other important environmental issues that society should deal with in the future.

Quaternary geomorphology of the Siljan area, central Sweden

We present a 1:100,000 scale Quaternary geomorphic map covering 2500 km2 in Central Sweden and including the Siljan Impact Structure. Because of the crater, the area is currently under consideration to become a geopark, and this project was undertaken to document Quaternary geology that may be of interest to park organizers and future visitors.A high-resolution digital elevation model with a vertical resolution of 0.25 m and a lateral resolution of 2.0 m was used as the base to map sub-, pro-, and post-glacial landforms. Consideration of the suite of landforms indicates ice flow from the northwest, multiple paleo-lake levels, and unstable landscapes into the Holocene. Additionally, the impact structure has played a role in routing both glacial and post-glacial drainage.

Lithostratigraphy of gold-bearing Quaternary gravels, middle Manuherikia Valley, Central Otago, New Zealand

The oldest fluvial Quaternary gravels exposed in the middle Manuherikia Valley in the Central Otago goldfield consist predominantly of rounded and angular quartz, with subordinate schist clasts. These sediments occur in a mappable middle Quaternary unit, herein defined as the Tinkers Formation (new name) that is well exposed in historic gold mine excavations. The unit contains placer gold and has been locally mined. The proportion of schist clasts increases up-section in the formation, to make up at least 30% of the gravels. Gravel beds in the formation are interlayered with loess horizons and minor mudstone (1–4 m scale). The Tinkers Formation is unconformably overlain by coarse poorly rounded immature schist gravel that contains dispersed gold but has not been mined. The gravel units have been folded and faulted along the actively deforming Dunstan Range front, from which the gravels have been derived. Ongoing uplift and recycling of sediments and contained gold has yielded younger gold-bearing gravel units. The gravel sequence in the middle Manuherikia Valley is distinctly different from elsewhere in the Manuherikia Valley, where recycled greywacke clasts form a persistent and locally major component of Quaternary sediments. Lithostratigraphic definition and mapping of Quaternary gravels has some advantages over correlation of Quaternary surfaces, which has been the most commonly used approach to Quaternary mapping in the Central Otago goldfield, and the two approaches are complementary.

Late Quaternary Slip‐Rate Variations along the Warm Springs Valley Fault System, Northern Walker Lane, California–Nevada Border

The extent to which faults exhibit temporally varying slip rates has important consequences for models of fault mechanics and probabilistic seismic hazard. Here, we explore the temporal behavior of the dextral‐slip Warm Springs Valley fault system, which is part of a network of closely spaced (10–20 km) faults in the northern Walker Lane (California–Nevada border). We develop a late Quaternary slip record for the fault using Quaternary mapping and high‐resolution topographic data from airborne Light Distance and Ranging (LiDAR). The faulted Fort Sage alluvial fan (40.06° N, 119.99° W) is dextrally displaced ![Graphic][1] , and we estimate the age of the alluvial fan to be ![Graphic][2] to 55.7±9.2 ka, based on a terrestrial cosmogenic ![Graphic][3] depth profile and ![Graphic][4] analyses on basalt boulders, respectively. The displacement and age constraints for the fan yield a slip rate of ![Graphic][5] to ![Graphic][6] (2 σ ) along the northern Warm Springs Valley fault system for the past 41.4–55.7 ka. In contrast to this longer‐term slip rate, shorelines associated with the Sehoo highstand of Lake Lahontan (∼15.8 ka) adjacent to the Fort Sage fan are dextrally faulted at most 3 m, which limits a maximum post‐15.8 ka slip rate to 0.2 mm/yr. These relations indicate that the post‐Lahontan slip rate on the fault is only about one‐tenth the longer‐term (41–56 ka) average slip rate. This apparent slip‐rate variation may be related to co‐dependent interaction with the nearby Honey Lake fault system, which shows evidence of an accelerated period of mid‐Holocene earthquakes. [1]: /embed/inline-graphic-1.gif [2]: /embed/inline-graphic-2.gif [3]: /embed/inline-graphic-3.gif [4]: /embed/inline-graphic-4.gif [5]: /embed/inline-graphic-5.gif [6]: /embed/inline-graphic-6.gif

Geomorphological map of the Tremiti Islands (Puglia, Southern Adriatic Sea, Italy), scale 1:15,000

This paper describes the Geomorphological map of the Tremiti Islands (Puglia, Southern Adriatic Sea, Italy), scale 1:15,000. The Tremiti Islands, located north of Gargano promontory's coast, are part of a complex geological area within the Adriatic basin, facing the junction between the central and southern Apennines. This area is well known for Neogenic-Quaternary stratigraphic, tectonic and seismologic aspects and is crucial for the definition of Late Quaternary Adriatic basin evolution. The map is the result of a geomorphological study carried out on the islands and the inner continental shelf around them. This study incorporates: (1) field recognition of Quaternary continental deposits and geomorphological mapping, supported by radiometric dating, focused on the morpho-lithostratigraphic correlation of deposits among the different islands and the recognition of landforms that controlled landscape evolution; (2) bathymetric analysis; (3) geomorphological analysis of data from a side scan sonar survey, focused on the recognition of the main submerged landforms, from the coastline down to about 70 m b.s.l.; and (4) scuba-dive geomorphological survey, for improving analysis of geophysical data with direct observations. The study outlines a complex geological and geomorphologic setting. Despite the small size of the islands, the Quaternary continental succession of the archipelago is characterized by widespread deposits, a result of slope, fluvial and aeolian environments. The landforms of the islands are related to karst, fluvial, marine, and gravitational processes. The inner continental shelf features marine and coastal landforms, but also tectonic, fluvial, karst, and slope landforms. The correlation of the below sea-level geomorphological features with landforms and deposits of above sea-level areas, has provided a contribution to the reconstruction of Late Quaternary landscape and geomorphological evolution, as the result of tectonics, sea-level fluctuations and marine, coastal, and continental geomorphological processes.

Stream plant chemistry as indicator of acid sulphate soils in Sweden

Results from the biogeochemical mapping (roots of aquatic plants and Fontinalis antipyretica) conducted by the Geological Survey of Sweden (SGU) reflects the metal load of surface waters draining acid sulphate (AS) soils in Sweden. In this study, results from the biogeochemical, soil geochemical and Quaternary mapping programmes at SGU were used to investigate the impact of fine-grained deposits hosting AS soils on stream water trace element chemistry in two separate areas. In the area around Lake Mälaren, postglacial sediments contain the highest levels of most trace elements studied. Owing to the low pH of AS soils and subsequent leaching, levels of nickel (Ni), cobalt (Co), copper (Cu), sulphur (S), yttrium (Y), uranium (U), tungsten (W), and molybdenum (Mo) were significantly elevated in aquatic roots. Levels were lower in the Skellefteå area, which may be explained by lower concentrations in source deposits. Concentrations of arsenic (As) and lead (Pb) were normal or impoverished in biogeochemical samples from postglacial, finegrained sediment areas. Maps based on ratios (Ni:Pb or Y:Pb) in biogeochemical samples can, together with results from Quaternary mapping, be used to predict areas with AS soils in Sweden.;

Colophon, contents and introduction

This Review of Survey activities presents a selection of 22 papers reflecting the wide spectrum of activities of the Geological Survey of Denmark and Greenland, from the microscopic to the plate-tectonic level.The Survey's activities in Denmark are illustrated by 13 articles. Five of them deal with petroleum-related topics and two others with groundwater-related topics. Four others describe raw material activities and environmental change, one paper presents a new Base Quaternary map of Denmark and one paper describes the deep structure below Denmark.Activities in Greenland are covered by five papers. Three of these address mineral and petroleum exploration, one concerns monitoring of the Greenland ice sheet and one focuses on historic investigations of Hans Ø, a small island in Nares Strait between Greenland and Canada.International projects and two new geoscientific methods: The survey also carries out many projects outside Denmark, Greenland and the Faroe Islands. This bulletin includes descriptions of a coastal protection project in Kenya and a multinational project dealing with the implementation of the European Union's Water Framework Directive. Finally, two examples of new developments in instrumental geoscience are presented.

Unidades quaternárias e vegetação nativa de planície costeira e baixa encosta da Serra do mar no litoral norte de São Paulo

Na zona costeira do Estado de São Paulo, apesar das fortes pressões sócioeconômicas para a utilização de seus recursos e espaços naturais, ainda podem ser encontrados importantes remanescentes de Mata Atlântica e ecossistemas associados, principalmente no Litoral Norte. Estes ecossistemas incluem os manguezais e todas as demais vegetações presentes nas planícies costeiras e baixas encostas da Serra do Mar (vegetação de “restinga”), as quais são caracterizadas pela estreita relação que guardam com o substrato sedimentar que recobrem. Este trabalho apresenta os resultados de mapeamentos realizados no Litoral Norte de São Paulo e tem os seguintes objetivos: atualizar os mapas do Quaternário costeiro realizados na década de 1970, realizar o mapeamento pioneiro das fitofisionomias de “restinga” descritas na Resolução Conama nº 07/1996, estabelecer as associações entre as Unidades Geológico-Geomorfológicas Quaternárias e essas fitofisionomias e calcular as porcentagens de supressão da vegetação nativa em relação à paisagem original na área de estudo.

Multimedia exploration strategies for PGEs: insights from the Surficial Geochemistry Case Studies Project, Lake Nipigon Region Geoscience Initiative, northwestern Ontario

The Surficial Geochemistry Case Studies Project in the Lake Nipigon region involved detailed Quaternary mapping and multimedia geochemical sampling within five case study areas. Two of these areas, Lac des Iles and Tib Lake, contain known platinum group element (PGE) mineralization. The other three case study areas feature drainage catchments with lakes that contain anomalous levels of PGEs in bottom sediment. Surficial media sampled included till, soils, stream sediment, lake sediment, peat, surface water, and groundwater. Over Archean terrain, such as at Lac des Iles and Tib Lake, there is excellent geochemical contrast between the PGE prospective rock type (mafic to ultramafic intrusive) and the surrounding rock type (e.g., granitoid rocks). This geochemical contrast is mirrored in the geochemistry of most surficial media sampled during this project. Over the Nipigon Embayment, the geochemical contrast between mafic and ultramafic rocks (e.g., “Seagull”-type intrusions) and the surrounding diabase sill rocks is inherently weaker due to the relatively high background levels for copper, palladium, and gold in the Nipigon diabase sills. However, the results of stream-water geochemistry over the Seagull and Disraeli ultramafic intrusions highlight their unique geochemical footprint on the surficial landscape, in particular with respect to Cr, Mg, and Ni, compared with the surrounding Nipigon diabase. In addition, lake sediments underlain by the Seagull, Disraeli, and Hele intrusions have distinctly elevated Cr concentrations and Gd/Yb ratios compared with the surrounding areas underlain by Nipigon diabase sills or Sibley Group rocks. Therefore, exploration value can be maximized over the Nipigon Embayment by exploiting these geochemical contrasts in surficial media to discriminate between ultramafic rocks and the surrounding Nipigon diabase sills. The results of this study highlight the importance of chromium concentrations in surficial media as a diagnostic feature for the presence of ultramafic rocks, regardless of their age or location. In general, a cost-effective exploration strategy for PGE mineralization includes targeting the associated metals (Cr, Ni) within drift deposits (C-horizon till) and drainage media (stream sediment, lake sediment) to vector to prospective mafic–ultramafic intrusive rocks, prior to detailed (property scale) follow-up, involving the determination of base metals and PGEs within soil, till, stream sediment, and peat samples. Relative to the metals copper, nickel, and chromium (ppm levels), the PGEs have significantly lower initial concentrations (ppb levels), are less mobile in the surficial environment, have significantly shorter glacial dispersion trains, and are less reliably determined at the laboratory.

Late Quaternary in northwestern Russia ‐ Introduction

Following reconnaissance work in 1994, a group offour Norwegian and Russian geologists in the summerof 1995 started working in river sections alongSevernaya Dvina and Vaga in the Arkhangelsk regionof northwestern Russia. This was the initiation of theDanish Norwegian Russian Swedish ArkhangelskProject, which in the following years evolved from shipand vehicle-borne 6 8 person expeditions along Sever-naya Dvina (1996 and 1997) and the Mezen RiverBasin (1997 and 1998) to ship and helicopter-borneexpeditions along the coasts of the White and Barentsseas, the Chyoshskaya Bay and on the Timan Ridge(2000, 2001, 2002) (Fig. 1). The expeditions thereforegrew in size and complexity over the years, as did thegeology encountered in the field areas as we movedfrom areas influenced only by the Scandinavian IceSheet to areas influenced also by the Barents Sea andthe Kara Sea ice sheets. The present volume sum-marizes the work carried out during these eightsummers. Our work was an integral part of theQUEEN Project (Quaternary Environment of theEurasian North), a European Science Foundationproject comprising fieldwork in northern Russia andSiberia and the adjacent seas. Much has already beenpublished in the series of collective volumes from thisproject (Larsen et al. 1999; Thiede et al. 2001, 2004).For the waxing and waning of ice sheets in Eurasiaduring the last ice age, the Arkhangelsk region holds astrategic position as a triple junction, because it wasoverridden by all three major Eurasian ice sheets: theScandinavian, the Barents Sea and the Kara Sea icesheets. While the first was mainly land-based andflowing out from the Fennoscandian mountains, theother two formed on the coastal shelf and moved ontoland. They therefore represent very different types ofice sheet, and this is reflected in their dynamic responseto external forcing. The unravelling of these glacialevents, and its relation to sea level and climate, hasbeen the main focus of our work.The Quaternary history of this region was firstoutlined by Wollosovich (1900) and Ramsay (1904),then by Lavrova (1937). These works contain manyprimary observations that are still valid. Later, com-prehensive surveys by Devyatova & Loseva (1964) andby Devyatova (1982) functioned scientifically as a fieldguide on Severnaya Dvina and in the Mezen Basin.Also regional Quaternary maps compiled by Lavrov(1977, 1991) provided highly useful overviews andnarrowed our scope to critical field areas.Since 1995, members of our project have documen-ted and logged more than 110 localities along the riversand coasts and surveyed many more (Fig. 1).Ice sheet dynamics from field studies and modelsLarsen et al. (2006a) offer a synthesis of the complexglacial and glaciolacustrine history of northwesternRussia, shown for the period 135 to 15 kyr BP in aseries of palaeo-geographical maps. Regional overviewsare presented in Demidov et al. (2006) for theScandinavian Ice Sheet and in Kjaer et al. (2006) for aspecific area around the Kanin Peninsula and Chyoshs-kaya Bay. The reconstruction of a mega-scale thrust-fault complex illustrates the ice/bed interaction andallows a palaeoenvironmental model to be establishedfor the earliest part of the Weichselian (Larsen et al.2006b). Lambeck et al. (2006) use the field observa-tions from this and other regions, e.g. Taimyr, to modelrelative sea level and changing ice cover over Eurasia inthe period c. 150 to 60 kyr BP.Sea-level changeGrosfjeld et al. (2006) give a detailed history of LateSaalian and Eemian relative sea level along the PyozaRiver, and Jensen et al. (2006) describe a MiddleWeichselian transgression which took place duringmajor regional deglaciation of the whole area at thetransition from MIS 4 to 3. The relative sea-level andisostatic history for the Late Saalian to the earlyHolocene is synthesized in Larsen et al. (2006a) andmodelled by Lambeck et al. (2006). Kjaer et al. (2006)explore the wider implications of rapid sea levelchanges and their impact on shelf-ice stability.The Eemian interglacialMarine sediments from the Eemian are widespread andform an important and readily recognizable stratigra-phical marker. A multi-palaeontological study gives adetailed account of hydrographical change and inflowof Atlantic water (Grosfjeld et al. 2006).

A provisional Quaternary and Neogene lithostratigraphical framework for Great Britain

AbstractThis paper presents an overview of a provisional lithostratigraphical framework for the Quaternary and Neogene deposits of Great Britain (England, Scotland and Wales) (onshore). The objective is to provide a workable framework to aid future Quaternary mapping and research, and a stratigraphical scheme capable of use in a wide variety of applications. Using the full hierarchy, a supergroup, group and subgroup lithostratigraphy, based upon the primary mapping unit, the formation, is proposed. It is recommended that some classes of lithogenetically-defined deposits which, at present cannot be accorded formational status, should be assigned informally to one of the proposed groups or subgroups. The framework distinguishes one superficial deposits supergroup within which seven groups are defined: i) Crag Group, marine deposits (Late Pliocene to Early Pleistocene); ii), Dunwich Group, fluvial deposits (pre-Anglian/pre-Elsterian); iii) Residual Deposits Group; iv) British Coastal Deposits Group, coastal and marine deposits (Anglian to Holocene); v) Britannia Catchments Group, fluvial, organic and mass movement deposits (Anglian to Holocene) within broadly defined catchment areas related to Late Devensian to present-day physiography; vi) Albion Glacigenic Group, glacigenic deposits (pre-Devensian/pre-Weichselian), and vii) Caledonia Glacigenic Group, glacigenic deposits (Devensian/Weichselian). North of the Devensian (Weichselian) ice-sheet limit, a series of glacigenic subgroups are defined geographically for the two glacigenic groups on the basis of mappable formations of till. The subgroups include associated formations of glaciofluvial and glaciolacustrine deposits. Consequently some of the glacigenic water-lain units may extend beyond the Devensian limit. Catchment subgroups of the Britannia Catchments Group are proposed for formations and lithogenetic units defined within broad present-day physiographic regions by major river drainage systems that have developed since Middle Pleistocene time. Lithostratigraphical description and correlation of formations will aid the refinement of the proposed framework and enable the development of lithostratigraphical maps and three-dimensional models. As well as offering a unified framework for onshore Quaternary and Neogene deposits the proposed supergroup, group and subgroup structure may prove useful for a wide range of regional applications (e.g. hydrological, hydrogeological, engineering).

Mikulino and Valdai palaeoenvironments in the Vologda area, NW Russia

Nine representative sediment sequences and pollen diagrams obtained during the Quaternary mapping programme carried out by the Geological Expedition (St. Petersburg, Russia) between 1960s and 1980s are presented from the Vologda area, NW Russian Plain, covering the time span from the Moscow cold (Saale) stage into the Late Valdai (Weichsel) substage. This work was done in order to shed light on the evolution of palaeoenvironments, vegetation and climate in the area. The results suggest that two major depressions in the Vologda area, namely the Mologa–Sheksnian and Prisukhonian basins, witnessed lake level fluctuations that were most likely closely linked to climatic fluctuations. It is suggested that during the Mikulino (Eem) thermal optimum most of the lowland areas were dry land. However, during the Early and Middle Valdai, the large depressions started to flood as a result of wet and cold climate. This caused the accumulation of lacustrine and also lacustrine–alluvial and lacustrine–bog sediments into the basins. The Valdai forest composition varied between closed spruce–birch forests and treeless tundra. Lakes persisted throughout the Valdai stage including the extremely dry last glacial maximum (LGM)-time when the Scandinavian Ice Sheet dammed the northbound rivers in the Vologda area.

Preglacial archaeological evidence at Grimshaw, the Peace River area, Alberta: Reply

An assemblage of quartzite cobbles with attributes of cultural flaking and utilization has been recorded at the base of a Laurentide till at the contact with underlying fluvial gravels in a section face of a gravel pit near Grimshaw in the course of Quaternary geology mapping of the Peace River area. The geological context, with secondarily redeposited stone artifacts, documents distortion of an early prehistoric site located in a nonglacial riverine setting by the expanding Late Wisconsinan continental ice from the north. The lithic assemblage provides further evidence for an earlier (pre-last glacial) occupation of North America, predating the earliest postglacial (<11 500 BP) Palaeoindian cultures, traditionally regarded as the hallmark of peopling of the New World.