DOCSLIB.ORG

Geological Survey of Finland

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geological Survey of Finland Geological Survey of Finland Bulletin 352 New cores from Eemian interglacial deposits in Ostrobothnia, Finland by Tuulikki Grönlund Geologian tutkimuskeskus Espoo 1991 Geological Survey of Finland, Bulletin 352 NEW CORES FROM EEMIAN INTERGLACIAL DEPOSITS IN OSTROBOTHNIA, FINLAND by TUULIKKI GRÖNLUND with 10 figures in the text and 2 plates and 2 appendices GEOLOGIAN TUTKIMUSKESKUS ESPOO 1991 Vammala 1991 , Vammalan Kirjapaino Oy Grönlund, Tuulikki 1991. New co res from Eemian interglacial deposits in Ostroboth­ nia, Finland. Geological Survey oj Finland, Bulletin 352, 23 pages, 10 figures, 2 plates and 2 appendices. Till-covered sediments containing marine diatoms have been found at Norinky­ lä (Teuva) and Ukonkangas (Kärsämäki) in Ostrobothnia, western Finland. The different types of diatom stratigraphy at these sites are described, and the sites are correlated with the Eemian interglacial stage. At Norinkylä, Eemian marine deposits are underlain by freshwater deposits whose diatom flora contains the same taxa as the Holocene Ancylus Lake. The deposits of the Eemian Baltic Sea proper at Ukonkangas and Norinkylä have a rich marine diatom flora with the same taxa as encountered earlier in Eemian deposits in Ostrobothnia. The phases of the Eemian Baltic Sea are discussed. Key words: stratigraphy, diatoms, interglacial environment, marine environment, freshwater environment, sediments, Eemian, Baltic Sea, Ostrobothnia, Finland. Tuulikki Gränlund, Geological Survey oj Finland, SF-02150 Espoo, Finland ISBN 951-690-417-3 ISSN 0367-522-X CONTENTS Introduction ........................................................ 5 Sampling and methods ...... ..... .. .. ..... .... ................... 6 The Norinkylä site at Teuva .......................................... 6 Core A ...... .. ...... .. ...... .. .. ... .. ... ... .. ..... .... ...... .. 7 Core B 10 Core C 13 Core D 13 Open section of the Haapalankangas esker at Jurva . ... ... .... ... .. 15 The Ukonkangas site at Kärsämäki . ... ..... ......... .... ...... .... .. 15 Discussion ... .. .. .. ... ... ... ...... ...... ....... .. .. ... ... ..... 17 Conclusion ....... ....... .. .. .. .... ... ................ .. .. ...... 19 Acknowledgements .... .... ..... ...... .......... ... ........... 22 References ............................... .. ......................... 22 Plates Appendices INTRODUCTION In recent years, sediments containing diatoms land. Many of these sediments can be interpreted have been found underlying glacial till at several as having deposited in the Baltic Sea basin dur­ sites, particularly in Ostrobothnia, western Fin- ing the last, i .e., the Eemian, interglacial stage. FINLAND SWEDEN USSR ,~ .ROVA I 64° r- 64° ~'& )~~ . OLLALA f / 0" • UKONKANGAS ~Qj ;: Q:) 0 0 ~ ~ • EVIJÄRVI 0V ( " • HIETAKANGAS ":> .VIITALA o : HAAPALANKANGAS ~ ! NORINKYLÄ OnegO : BOLLNÄS • ,I Bothnian Sea . SOMERO 0 HELSINKI F·n1and .MGA 11 ) PRANGLI NYKOPING ~f' ESTONIA 11 Baltic Sea ( 250 h- I 300 km Fig. I. A) A map showing lhe main localilies of Eemian marine dialOm bearing sedi· ments in Fennoscandia and lhe nonh-weslern Soviel Union and lhe siles menlioned in lhe lext. B) A localion map of Fennoscandia, lhe nonh-weslern Soviel Union and the Ballic Sea. Ostrobolhnia is indicaled by shading. 6 Geological Survey of Finland. Bulletin 352 The correlation is based on lithm,tratigraphy and or mixed with freshwater diatom flora in several pollen stratigraphy. The main Eemian marine places in Finland, Sweden and Soviet Karelia sites in Finland studied by means of diatoms are (e .g. Halden 1915, Brander 1937 a, b, 1943, Tyn­ Evijärvi (Eriksson et a/. 1980), Ollala (Haapavesi) ni 1971, Miller & Persson 1973, Niemelä & Tyn­ (Forsström et a/. 1987, 1988 and Grönlund 1988) ni 1979, Grönlund et a/. 1985, Passe et a/. 1988, and Viitala (Peräseinäjoki) (Nenonen el a/. in Garcia Ambrosiani 1990). press). The location of the sites i5, shown in Figure New coring was undertaken at Norinkylä (Teu­ I. The Eemian Baltic Sea diatom flora of Suur­ va), the si te already studied by Niemelä and Tyn­ Prangli, nowadays Prangli (see Liivrand in ni (1979) and Donner (1988). Sampies were also press), an island off the coast of northern Esto­ taken from a silt deposit underlying till at nia, has also been presented, first by Chere­ Ukonkangas (Kärsämäki) and Haapalankangas misinova (I961) and later by Lii vrand (1984, (Jurva) (Fig.l). The diatom stratigraphy of these 1987, in press) on the basis of the diatom studies sites is presented in order to provide new infor­ of Cheremisinova (Fig. I). Eemian marine mation about the Eemian Baltic Sea, its north­ deposits and diatoms are also found redeposited ern and northeastern parts in particular. SAMPLING AND METHODS At Norinkylä the sam pies were taken using a sampie depth. percussion drill with a flow-through bit sampier . The diatoms were c1assified according to At Ukonkangas and Haapalankangas they were salinity preference as polyhalobous (salinity in the taken by spade from an exposed section. habitat 35-17 parts per mille), mesohalobous in­ The sam pies were first bleached with diluted c1uding meso- and pleioeyryhaline polyhalobous H 20 2 for 24 h at 50°C, and then subjected to (salinity in the habitat 35-3 parts per mille) and repeated suspensions and decantations. The oligohalobous, which are freshwater species. The mounting medium was Hyrax Liquid with a c1assification is that of Simonsen {I 962) as refractive index of 1.65. Whenever possible, at applied to Finnish conditions by Tynni (Nieme­ least 500 diatom valves were iclentified from each lä & Tynni 1979). THE NORINKYLÄ SITE AT TEUVA The Norinkylä site lies in the municipality of 110 m above sea level because a 2-3 m thick till Teuva (62°35 ' 45' 'N and 22 "01' 07' 'E) (Fig. 1). bed had been removed from the surface. A dis­ The sequence occurs in a narrow till-covered turbed c1ay layer, about 12 cm thick, was in­ esker trending north to south, and bounded on c1uded in the section studied by Niemelä and Tyn­ its western side by Rahkaneva mire. ni (1979). This c1ay contained a marine diatom The Norinkylä site was first studied by Niemelä flora with species commonly found in marine and Tynni (J 979). The section they studied was Eemian deposits. According to Niemelä and Tyn­ on the western slope of the esker, with its crest ni, the c1ay had deposited c10se to the shore dur­ at 112 m above sea level. When Donner (I988) ing the Eemian marine stage. This marine Eemian later studied the same site, the crest was at c1ay was not encountered in the section studied Geological Survey of Finland, Bulletin 352 7 SE ~ --,--,_ _ -----:---'110m o s l '"I" " r;....~ " " I'. /'; " " " C PEAT I'. " ~~: " w TILL ~ IT'MB FINE WATE RLAIN SED IMENTS I SILT. GYTTJA SI LT. SAN D I ------, 50 100 150m Fig. 2. COTes from the Norinkylä (Teuva) site. Co res A, B, C and D were sludied. by Donner (1988). Besides the clay layer, there 30 cm of clay, the lower part of which is mixed was a lens of gyttja (organic mud) with marine with the till deposit (Fig. 3 and Appendices 1-2). diatoms in its upper part, although the rest of the The uppermost part of the silt layer was probably gyttja was regarded as a freshwater deposit. This cut away when the overlying till deposited or then gyttja had later been mixed with probably re~ it was missed in sampling. worked sediments containing Eemian diatoms The succession of the diatom taxa is given in (Niemelä & Tynni 1979). Appendix 1 (polyhalobous and mesohalobous New sampies for diatom analysis were col~ species) and Appendix 2 (freshwater species). The lected from the Rahkaneva mire in 1987 and diatoms, classified according to their salinity and 1989. The sam pie site lies northwest of the sec~ temperature demands (cold or warm water con~ tion studied by Niemelä and Tynni (1979) and ditions) mainly after Hustedt (1930), Cleve-Euler Donner (1988), in the direction from which the (1940), Miller (J964) and Guillard and Kilham glacier approached. Eighteen attempts to drill (1977), are presented in Figure 3. Environmen­ good cores through very hard till deposits with tal changes shown by dia tom stratigraphy are also big boulders (cL Fig. 2) produced only four satis­ shown. The lowermost sampie of the core, from factory cores (A-D). Their distances from the a depth of 12.75 m, contains a small number of section studied by Niemelä and Tynni and Don­ diatoms (Fig. 3). The main species are the meso­ ner were as folIows: core A 120 m, core B 130 halobous Grammatophora oceanica Grunow and m, co re C 140 m and core D 175 m (Fig. 2) . Rah­ Hyalodiscus scoticus (Kützing) Grunow, both kaneva mire is at 110 m a.s.l. The thickness of earlier interpreted as typical of the Eemian Bal~ the peat layer overlying the till deposits is 0- tic Sea. Aulacoseira lirala (Ehrenberg) Ross 3 m at the sites of the cores studied. (Aulacoseira = Melosira, see Simonsen 1979 and e.g. Hartley 1986), which is a freshwater species, is also common. Otherwise the clay layer in the Core A bottom of the co re contains diatoms characteris­ The core, almost 4 m long, consists of organic tic of freshwater conditions, with Aulacoseira silt covered by till. The silt is underlain by about lirata, A. islandica (0. Müller) Simonsen and A. 8 Geological Survey of Finland, Bulletin 352 Core A. NOTri_n_kr-y_llI____ _ DIATOMS [[] POLYHALOBOUS V1 >­ V1 I IrCl. '3 <{ MESOHALOBOUS a: c:J z !2 9 I t:: ~ >­ a: Cl. OLiGOHALOBOUS ;; z >­ W Jillli~ z !2 V1 o w 560 520 E 500 500 E 550 550 M 510 I 52051.0 A 550 N 500 500 S E 550 \ A 51.0 500 ( ·580 500 550 ) 510 \ 630 I 520 515 , 500 550 1 515 -1 \ 560 500 '2 500 500 --- - ---j== -===t ( 55 107 "RESH 300 WAT ER [-= . 150 .., .~ .., ~ "----'------'--~ L-_ % 10 % 10 20 30 1. 0 50 60 70 80 90 100 o 10 =-~ ~CLAY . GYT JA S L' Fig. 3. Diatom groups by salinity, temperature dema nd (lhermophilous and cryophilous species) a nd changes in sedimentary environment (lake/ sea) according 10 the diatom spectra in co re A, Norinkylä. Geological Survey of Finland, Bulletin 352 9 islandica subsp.
Load more

Recommended publications
  • The Eemian - Local Sequences, Global Perspectives: Introduction
    Geologie en Mijnbouw / Netherlands Journal of Geosciences 79 (2/3): 129-133 (2000) The Eemian - local sequences, global perspectives: introduction Thijs van Kolfschoten1 & Philip L. Gibbard2 1 Faculty of Archaeology, Leiden University, P.O. Box 9515, 2300 RA LEIDEN, the Netherlands; Corresponding author; e-mail: [email protected] 2 Godwin Institute of Quaternary Research, Department of Geography, University of Cambridge, Downing Street, CAMBRIDGE CB2 3EN, England; e-mail:[email protected] Received: May 2000; accepted in revised form: 20 June 2000 G The history of this special issue gation and discussion on the Middle/Late Pleistocene boundary on the original type area of the Eemian in The history of this volume goes back to a 1973 IN- the Netherlands. The Eemian sequence was often QUA congress in New Zealand, where an INQUA used as reference and furthermore the term 'Eemian' Commission of Stratigraphy working group on major was widely used to identify the last interglacial far be­ subdivisions of the Pleistocene was established. The yond western central Europe. Examination of the Pleistocene series/epoch was hitherto generally subdi­ available data from the Eemian type area showed that vided into the Lower/Early, Middle and Upper/Late a re-evaluation of existing data and collection of criti­ Pleistocene (see, among others, Zeuner, 1935, 1959) cal new data were needed to define an unambiguous but the boundaries between these subseries/sube- stratigraphical boundary. Although the identification pochs were not formally defined. The boundary be­ of boundaries is central to stratigraphical subdivision, tween the Early and Middle Pleistocene was, in the it is nevertheless the Eemian as an entity that is of European literature, put at the base of the Cromerian particular interest for understanding the development Complex (Zagwijn, 1963) or at the Brunhes/Matuya- of a complete interglacial cycle.
    [Show full text]
  • WELLESLEY TRAILS Self-Guided Walk
    WELLESLEY TRAILS Self-Guided Walk The Wellesley Trails Committee’s guided walks scheduled for spring 2021 are canceled due to Covid-19 restrictions. But… we encourage you to take a self-guided walk in the woods without us! (Masked and socially distanced from others outside your group, of course) Geologic Features Look for geological features noted in many of our Self-Guided Trail Walks. Featured here is a large rock polished by the glacier at Devil’s Slide, an esker in the Town Forest (pictured), and a kettle hole and glacial erratic at Kelly Memorial Park. Devil’s Slide 0.15 miles, 15 minutes Location and Parking Park along the road at the Devil’s Slide trailhead across the road from 9 Greenwood Road. Directions From the Hills Post Office on Washington Street, turn onto Cliff Road and follow for 0.4 mile. Turn left onto Cushing Road and follow as it winds around for 0.15 mile. Turn left onto Greenwood Road, and immediately on your left is the trailhead in patch of woods. Walk Description Follow the path for about 100 yards to a large rock called the Devil’s Slide. Take the path to the left and climb around the back of the rock to get to the top of the slide. Children like to try out the slide, which is well worn with use, but only if it is dry and not wet or icy! Devil’s Slide is one of the oldest rocks in Wellesley, more than 600,000,000 years old and is a diorite intrusion into granite rock.
    [Show full text]
  • An Esker Group South of Dayton, Ohio 231 JACKSON—Notes on the Aphididae 243 New Books 250 Natural History Survey 250
    The Ohio Naturalist, PUBLISHED BY The Biological Club of the Ohio State University. Volume VIII. JANUARY. 1908. No. 3 TABLE OF CONTENTS. SCHEPFEL—An Esker Group South of Dayton, Ohio 231 JACKSON—Notes on the Aphididae 243 New Books 250 Natural History Survey 250 AN ESKER GROUP SOUTH OF DAYTON, OHIO.1 EARL R. SCHEFFEL Contents. Introduction. General Discussion of Eskers. Preliminary Description of Region. Bearing on Archaeology. Topographic Relations. Theories of Origin. Detailed Description of Eskers. Kame Area to the West of Eskers. Studies. Proximity of Eskers. Altitude of These Deposits. Height of Eskers. Composition of Eskers. Reticulation. Rock Weathering. Knolls. Crest-Lines. Economic Importance. Area to the East. Conclusion and Summary. Introduction. This paper has for its object the discussion of an esker group2 south of Dayton, Ohio;3 which group constitutes a part of the first or outer moraine of the Miami Lobe of the Late Wisconsin ice where it forms the east bluff of the Great Miami River south of Dayton.4 1. Given before the Ohio Academy of Science, Nov. 30, 1907, at Oxford, O., repre- senting work performed under the direction of Professor Frank Carney as partial requirement for the Master's Degree. 2. F: G. Clapp, Jour, of Geol., Vol. XII, (1904), pp. 203-210. 3. The writer's attention was first called to the group the past year under the name "Morainic Ridges," by Professor W. B. Werthner, of Steele High School, located in the city mentioned. Professor Werthner stated that Professor August P. Foerste of the same school and himself had spent some time together in the study of this region, but that the field was still clear for inves- tigation and publication.
    [Show full text]
  • The History of Ice on Earth by Michael Marshall
    The history of ice on Earth By Michael Marshall Primitive humans, clad in animal skins, trekking across vast expanses of ice in a desperate search to find food. That’s the image that comes to mind when most of us think about an ice age. But in fact there have been many ice ages, most of them long before humans made their first appearance. And the familiar picture of an ice age is of a comparatively mild one: others were so severe that the entire Earth froze over, for tens or even hundreds of millions of years. In fact, the planet seems to have three main settings: “greenhouse”, when tropical temperatures extend to the polesand there are no ice sheets at all; “icehouse”, when there is some permanent ice, although its extent varies greatly; and “snowball”, in which the planet’s entire surface is frozen over. Why the ice periodically advances – and why it retreats again – is a mystery that glaciologists have only just started to unravel. Here’s our recap of all the back and forth they’re trying to explain. Snowball Earth 2.4 to 2.1 billion years ago The Huronian glaciation is the oldest ice age we know about. The Earth was just over 2 billion years old, and home only to unicellular life-forms. The early stages of the Huronian, from 2.4 to 2.3 billion years ago, seem to have been particularly severe, with the entire planet frozen over in the first “snowball Earth”. This may have been triggered by a 250-million-year lull in volcanic activity, which would have meant less carbon dioxide being pumped into the atmosphere, and a reduced greenhouse effect.
    [Show full text]
  • Eskers Formed at the Beds of Modern Surge-Type Tidewater Glaciers in Spitsbergen
    CORE Metadata, citation and similar papers at core.ac.uk Provided by Apollo Eskers formed at the beds of modern surge-type tidewater glaciers in Spitsbergen J. A. DOWDESWELL1* & D. OTTESEN2 1Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER, UK 2Geological Survey of Norway, Postboks 6315 Sluppen, N-7491 Trondheim, Norway *Corresponding author (e-mail: [email protected]) Eskers are sinuous ridges composed of glacifluvial sand and gravel. They are deposited in channels with ice walls in subglacial, englacial and supraglacial positions. Eskers have been observed widely in deglaciated terrain and are varied in their planform. Many are single and continuous ridges, whereas others are complex anastomosing systems, and some are successive subaqueous fans deposited at retreating tidewater glacier margins (Benn & Evans 2010). Eskers are usually orientated approximately in the direction of past glacier flow. Many are formed subglacially by the sedimentary infilling of channels formed in ice at the glacier base (known as ‘R’ channels; Röthlisberger 1972). When basal water flows under pressure in full conduits, the hydraulic gradient and direction of water flow are controlled primarily by ice- surface slope, with bed topography of secondary importance (Shreve 1985). In such cases, eskers typically record the former flow of channelised and pressurised water both up- and down-slope. Description Sinuous sedimentary ridges, orientated generally parallel to fjord axes, have been observed on swath-bathymetric images from several Spitsbergen fjords (Ottesen et al. 2008). In innermost van Mijenfjorden, known as Rindersbukta, and van Keulenfjorden in central Spitsbergen, the fjord floors have been exposed by glacier retreat over the past century or so (Ottesen et al.
    [Show full text]
  • Trip F the PINNACLE HILLS and the MENDON KAME AREA: CONTRASTING MORAINAL DEPOSITS by Robert A
    F-1 Trip F THE PINNACLE HILLS AND THE MENDON KAME AREA: CONTRASTING MORAINAL DEPOSITS by Robert A. Sanders Department of Geosciences Monroe Community College INTRODUCTION The Pinnacle Hills, fortunately, were voluminously described with many excellent photographs by Fairchild, (1923). In 1973 the Range still stands as a conspicuous east-west ridge extending from the town of Brighton, at about Hillside Avenue, four miles to the Genesee River at the University of Rochester campus, referred to as Oak Hill. But, for over thirty years the Range was butchered for sand and gravel, which was both a crime and blessing from the geological point of view (plates I-VI). First, it destroyed the original land form shapes which were subsequently covered with man-made structures drawing the shade on its original beauty. Secondly, it allowed study of its structure by a man with a brilliantly analytical mind, Herman L. Fair­ child. It is an excellent example of morainal deposition at an ice front in a state of dynamic equilibrium, except for minor fluctuations. The Mendon Kame area on the other hand, represents the result of a block of stagnant ice, probably detached and draped over drumlins and drumloidal hills, melting away with tunnels, crevasses, and per­ foration deposits spilling or squirting their included debris over a more or less square area leaving topographically high kames and esker F-2 segments with many kettles and a large central area of impounded drainage. There appears to be several wave-cut levels at around the + 700 1 Lake Dana level, (Fairchild, 1923). The author in no way pretends to be a Pleistocene expert, but an attempt is made to give a few possible interpretations of the many diverse forms found in the Mendon Kames area.
    [Show full text]
  • Late Pleistocene Climate Change and Its Impact on Palaeogeography of the Southern Baltic Sea Region
    Late Pleistocene climate change and its impact on palaeogeography of the southern Baltic Sea region Leszek Marks Polish Geological Institute–National Research Institute, Warsaw, Poland Department of Climate Geology, University of Warsaw, Warsaw, Poland Main items • Regional bakground for climatic impact of the Eemian sea • Outline of Eemian climate changes in the adjoining terrestrial area • Principles of Central European climate during the last glacial stage • Climate change at the turn of Pleistocene and Holocene Surface hydrography of the Baltic Sea PRESENT EEMIAN SALINITY OF SURFACE WATER: dark blue – >30‰, light blue – 25-30‰, brown – 15-25‰, yellow – 5-15‰, red – <5‰ CURRENTS INDICATED BY ARROWS: red – warm surface current, blue – cold bottom current, green – brackish surface current (≈10‰), stripped red/yellow – coastal water surface current (>15‰), yellow – major source of river runoff Funder 2002) Eemian sea in the Lower Vistula Valley Region Cierpięta research borehole Cierpięta Makowska (1986), modified Chronology of Eemian based on pollen stratigraphy RPAZ after Mamakowa (1988, 1989) Head et al. (2005) Correlation of Eemian LPAZ with RPAZ in southern Baltic region Knudsen et al. (2012) Chronology of Eemian sea in southern Baltic region Top of Eemian deposits ca. 8500–11 000 yrs Boundary E5/E6 7000 lat Top of marine Eemian deposits Boundary E4/E5 3000 yrs Boundary E3/E4 750 yrs Boundary E2/E3 300 yrs E1 or E2 <300 yrs Bottom of marine Eemian deposits Boundary Saalian/Eemian 0 (126 ka BP) Based on correlation with regional pollen
    [Show full text]
  • Greenland Climate Simulations Show High Eemian Surface Melt Which Could Explain Reduced Total Air Content in Ice Cores
    Clim. Past, 17, 317–330, 2021 https://doi.org/10.5194/cp-17-317-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Greenland climate simulations show high Eemian surface melt which could explain reduced total air content in ice cores Andreas Plach1,2,3, Bo M. Vinther4, Kerim H. Nisancioglu1,5, Sindhu Vudayagiri4, and Thomas Blunier4 1Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway 2Department of Meteorology and Geophysics, University of Vienna, Vienna, Austria 3Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland 4Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark 5Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway Correspondence: Andreas Plach ([email protected]) Received: 27 July 2020 – Discussion started: 18 August 2020 Revised: 27 November 2020 – Accepted: 1 December 2020 – Published: 29 January 2021 Abstract. This study presents simulations of Greenland sur- 1 Introduction face melt for the Eemian interglacial period (∼ 130000 to 115 000 years ago) derived from regional climate simula- tions with a coupled surface energy balance model. Surface The Eemian interglacial period (∼ 130000 to 115 000 years melt is of high relevance due to its potential effect on ice ago; hereafter ∼ 130 to 115 ka) was the last period with a core observations, e.g., lowering the preserved total air con- warmer-than-present summer climate on Greenland (CAPE tent (TAC) used to infer past surface elevation. An investi- Last Interglacial Project Members, 2006; Otto-Bliesner et al., gation of surface melt is particularly interesting for warm 2013; Capron et al., 2014).
    [Show full text]
  • Late Weichselian and Holocene Shore Displacement History of the Baltic Sea in Finland
    Late Weichselian and Holocene shore displacement history of the Baltic Sea in Finland MATTI TIKKANEN AND JUHA OKSANEN Tikkanen, Matti & Juha Oksanen (2002). Late Weichselian and Holocene shore displacement history of the Baltic Sea in Finland. Fennia 180: 1–2, pp. 9–20. Helsinki. ISSN 0015-0010. About 62 percent of Finland’s current surface area has been covered by the waters of the Baltic basin at some stage. The highest shorelines are located at a present altitude of about 220 metres above sea level in the north and 100 metres above sea level in the south-east. The nature of the Baltic Sea has alter- nated in the course of its four main postglacial stages between a freshwater lake and a brackish water basin connected to the outside ocean by narrow straits. This article provides a general overview of the principal stages in the history of the Baltic Sea and examines the regional influence of the associated shore displacement phenomena within Finland. The maps depicting the vari- ous stages have been generated digitally by GIS techniques. Following deglaciation, the freshwater Baltic Ice Lake (12,600–10,300 BP) built up against the ice margin to reach a level 25 metres above that of the ocean, with an outflow through the straits of Öresund. At this stage the only substantial land areas in Finland were in the east and south-east. Around 10,300 BP this ice lake discharged through a number of channels that opened up in central Sweden until it reached the ocean level, marking the beginning of the mildly saline Yoldia Sea stage (10,300–9500 BP).
    [Show full text]
  • Pine Hill Esker Trail
    mature forest, crosses a meadow and goes back 1.04 miles: Trail turn-around, at the location of into forested terrain. Unique for this trail are its wetland and a permanent stream. eskers and kettle ponds and the views of a 1.19 miles: Optional (but recommended) side wetland pond where Rocky Brook flows into the loop on the left side, shortly after remnants of the Stillwater River. The trail is located on DCR circular track. watershed protection land, so dogs are not 1.23 miles: Trail loops gently to the right. Deep allowed. down to the left is a small pond (a kettle pond). Length and Difficulty 1.32 miles: Side trail rejoins the return trail. 1.55 miles: Trail junction of Sections A, B and C. For clarity, the trail is divided into three sections: The trail description continues with Sect. C A, B and C, with one-way lengths of 0.65 mi., 0.45 outbound. mi. and 0.45 mi., respectively. The full hike, as 1.58 miles: Wet area most of the times of the described below, includes all three sections. The year. side loop on Sect. B is included on the return. The 1.78 miles: View to wetland pond where the A+B+C trail length is 3.1 mi., while the two shorter Stillwater River meets Rocky Brook. The distant versions, A+B or A+C, are both 2.2 mi. in length. structure is part of the Sterling water system. The elevation varies between 428 ft and 540 ft, 2.00 miles: Trail turn around point at the edge of with several short steep hills.
    [Show full text]
  • Esker Habitat Characteristics and Traditional Land Use in the Slave Geological Province
    Re: Esker Habitat Characteristics and Traditional Land Use in the Slave Geological Province STUDY DIRECTOR RELEASE FORM The above publication is the result of a project conducted under the West Kitikmeot / Slave Study. I have reviewed the report and advise that it has fulfilled the requirements of the approved proposal and can be subjected to independent expert review and be considered for release to the public. Study Director Date INDEPENDENT EXPERT REVIEW FORM I have reviewed this publication for scientific content and scientific practices and find the report is acceptable given the specific purposes of this project and subject to the field conditions encountered. Reviewer Date INDEPENDENT EXPERT REVIEW FORM I have reviewed this publication for scientific content and scientific practices and find the report is acceptable given the specific purposes of this project and subject to the field conditions encountered. Reviewer Date BOARD RELEASE FORM The Study Board is satisfied that this final report has been reviewed for scientific content and approves it for release to the public. Chair West Kitikmeot/Slave Society Date Box 2572, Yellowknife, NT, X1A 2P9 Ph (867) 669-6235 Fax (867) 920-4346 e-mail: [email protected] Home Page: http://www.wkss.nt.ca ESKER HABITAT CHARACTERISTICS and TRADITIONAL USE STUDY in the SLAVE GEOLOGICAL PROVINCE FINAL REPORT to the WEST KITIKMEOT / SLAVE STUDY Submitted by: Stephen Traynor Senior Land Specialist – Land Administration Indian and Northern Affairs Canada Yellowknife, NT August 2001 SUMMARY In May of 1996 approval was granted and funding awarded by the West Kitikmeot Slave Study Society (WKSS) for a project to initiate research and information dissemination on eskers in the Slave Geological Province.
    [Show full text]
  • Late Quaternary Changes in Climate
    SE9900016 Tecnmcai neport TR-98-13 Late Quaternary changes in climate Karin Holmgren and Wibjorn Karien Department of Physical Geography Stockholm University December 1998 Svensk Kambranslehantering AB Swedish Nuclear Fuel and Waste Management Co Box 5864 SE-102 40 Stockholm Sweden Tel 08-459 84 00 +46 8 459 84 00 Fax 08-661 57 19 +46 8 661 57 19 30- 07 Late Quaternary changes in climate Karin Holmgren and Wibjorn Karlen Department of Physical Geography, Stockholm University December 1998 Keywords: Pleistocene, Holocene, climate change, glaciation, inter-glacial, rapid fluctuations, synchrony, forcing factor, feed-back. This report concerns a study which was conducted for SKB. The conclusions and viewpoints presented in the report are those of the author(s) and do not necessarily coincide with those of the client. Information on SKB technical reports fromi 977-1978 {TR 121), 1979 (TR 79-28), 1980 (TR 80-26), 1981 (TR81-17), 1982 (TR 82-28), 1983 (TR 83-77), 1984 (TR 85-01), 1985 (TR 85-20), 1986 (TR 86-31), 1987 (TR 87-33), 1988 (TR 88-32), 1989 (TR 89-40), 1990 (TR 90-46), 1991 (TR 91-64), 1992 (TR 92-46), 1993 (TR 93-34), 1994 (TR 94-33), 1995 (TR 95-37) and 1996 (TR 96-25) is available through SKB. Abstract This review concerns the Quaternary climate (last two million years) with an emphasis on the last 200 000 years. The present state of art in this field is described and evaluated. The review builds on a thorough examination of classic and recent literature (up to October 1998) comprising more than 200 scientific papers.
    [Show full text]