Danmarks Geologiske Undersøgelse II. Række
Danmarks Geologiske Undersøgelse II. Række was published by the Geological Survey of Denmark (Danmarks Geologiske Undersøgelse; DGU) between 1890 and 1983. It consists of 114 printed volumes of peer-reviewed monographs and research articles relevant to Danish geology and gesocience. DGU merged with the Geological Survey of Greenland (GGU) in 1995 to form a single organisation, GEUS. The two surveys maintained their own scientific series until these too were merged into one, GEUS Bulletin, in 2003. Danmarks Geologiske Undersøgelse II. Række is discontinued and is not open for submissions.
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Forest development, soil genesis and human activity illustrated by pollen and hypha analysis of two neighbouring podzols in Draved Forest, Denmark
A small investigation area, located in an old natural Fagus-Quercus forest, was selected for an analysis of vegetational development, soil genesis, human activity, and interaction between the processes. Podzol soils dominate the investigation area. The thickness of the humus cover varies between 5-52 cm. Two sections were excavated and material collected for pedological and microfossil analysis. Sites only 7 m apart were chosen to illustrate short-distance similarities and dissimilarities in soil development and pollen representation. Sediment accumulation curves are constructed on the basis of historical information on changes in forest composition dating back to AD 1750. Older sediments are dated from their pollen content, assuming a constant pollen influx, similar to the period AD 1750-1980. The accumulation curves reach back to the Subboreal and to the Middle Ages respectively. Relative and absolute pollen diagrams are constructed to show forest development. Concentration diagrams are calculated for the period prior to AD 1750, and an influx diagram covers the period AD 1750-1980. A primeval Tilia forest dominated the area until Late Subboreal, when human interference is first detected in one of the diagrams. Leaf-hay gathering by shredding, which did not substantially change the forest composition, was practiced until late in the Middle Ages, and the mixed Tilia vegetation persisted until about AD 1650 when the Tilia trees were felled and succeeded by a Quercus-Fagus-Betula vegetation which has dominated the area since. Changes in the use of the forest caused the death of the Tilia forest. Viscum album was present in Draved Forest until the eradication of its host. The presence of Viscum in the l6th-18th centuries indicates that this species tolerates lower summer temperature than earlier supposed. Comparison of the two percentage diagrams shows significant differences in pollen frequency, although the sites are located only 7 m apart. Similar pollen influx rates were calculated for both sites AD 1750-1980. The mean total pollen influx amounted to about 44000 pollen cm-2year-1 or 12-15000 APcorr. cm-2year-1. Distinct influx variations were recognized within smaller time units. Two types of pollen deterioration, corrosion and thinning, were distinguished and their influence on the pollen spectra analysed. The conclusion being that the pollen spectra are only slightly influenced by pollen deterioration, and differential pollen destruction does not seem to be an important source of error in pollen analysis from the raw humus stage, the arthropod humus stage, and the lumbricid humus stage. Pollen destruction was important only in the lumbricid humus stage, and both types of pollen deterioration are involved. Fungal hypha analysis includes total length measurements as well as the relative size distribution of hypha fragments. Litter composition strongly influences the annual growth of brown-coloured hyphae. The rate of litter decomposition is another important factor. The hypha production was slow in the lumbricid humus stage and accelerated in the arthropod- and raw humus stages. Hypha fragments in the soil show characteristic length-frequency distributions which indicate comminution by macro- and microarthropods during burial. The investigation has demonstrated a close relationship between soil development, forest composition and human activity. Anthropogenic disturbance and a changing forest composition accelerate soil development, which is also depending on lithology and topography. The development of a podzol was completed within a period of only 300 years in one of the sections, while it took more than 2000 years to reach the same state of maturity at the other site, only 7 m away.
Sandstones and phosphatized calcareous sediments of the Lower Cambrian Rispebjerg Sandstone, Bornholm, Denmark
The Rispebjerg Sandstone on the island of Bornholm, Denmark, consists of sandstone layers intercalated with phosphorite layers. The phosphorite lithology is composed of micritic phosphorite containing varying amounts of terrigenous grains and minor amounts of calcareous and non-calcareous allochems. Mineralogically, the micritic phosphorite is chiefly composed of carbonate-apatite, according to X-ray diffractograms. More or less complete calcite replacement by phosphate occurs both in the micrite and in the calcareous allochems. Bioturbation must have been intense as most depositional sedimentary structures have been destroyed. The most plausible explanation of the phosphorite lithology is that calcareous mud was deposited in a barred lagoon in which storms blew back sand from the barrier. Sand and mud were then mixed by bioturbation. Penecontemporaneously with the deposition of this sediment, phosphatization of calcite by phosphorous from sea water is judged to have occurred. The sandstone lithologies are calcitic siliceous submature glauconitic quartzarenite, calcitic submature quartzarenite and siliceous submature quartzarenite. Gravel-sized grains are present in the two latter sandstone types. All the sandstones are characterized by good roundness and moderate sorting. These textural parameters indicate textural inversion. The roundness is interpreted as inherited from older sediments. The sandstones may have been deposited in the tidal complex on the landward side of the sandy barrier. Scarce calcareous and phosphatic fossil fragments were locally found in rocks of all lithologies. Deposition of the Rispebjerg Sandstone was interrupted by periods of erosion, one of which originated the formation of an intraformational unconformity. Several diagenetical replacements - phosphatization, chertification, calcification, glauconitization, chloritization, pyritization - occurred during and after deposition of the Rispebjerg Sandstone.
Middle and Late Weichselian marine deposits at Nørre Lyngby, northern Jutland, Denmark, and their foraminiferal faunas
The marine Weichselian deposits at Nørre Lyngby are subdivided into four assemblage zones based on the content of benthonic foraminifera. The lowermost zone, the Bulimina marginata-Buccella frigida zone, is correlated with the upper part of the Older Yoldia Clay of Yendsyssel and inferred to be of Middle Weichselian interstadial age. The Elphidium subarcticum zone is correlated with the Lower Saxicava Sand and the Elphidium excavatum zone with the Younger Yoldia Clay of Vendsyssel. The E. subarcticum zone is found to be a sandy facies within the lower part of the E. excavatum zone at Nørre Lyngby. The foraminiferal faunas of these two zones indicate mainly artic climatic conditions. Radiocarbon dates show that the E. subarcticum zone and also a major part of the E. excavatum zone belong to late Middle Weichselian. The uppermost zone, the Elphidium albiumbilicatum zone, is correlated with the Upper Saxicava Sand. The foraminiferal faunas in this zone seem to indicate an amelioration in climate, and the deposit might be present the Late Weichselian Bølling interstadial.
The stratigraphy, structure and origin of glacial deposits in the Randers area, eastern Jutland
The investigations of the glacial sequence in the Randers area include mapping of the surface layers, study of bore profiles and detailed examination of outcrops, concentrating on the determination of transport directions in the deposits. The following stratigraphic succession has been established: Highest: NE till Tebbestrup Formation (melt water deposits) SE till Haldum Formation (melt water deposits) Lowest: NE till The two uppermost units can with certainty be referred to Weichselian. Arguments are presented that the three lowermost units are of Saalian age. The origin of the sequence is discussed. The highest hills in the area (Ølst, Lysnet) were probably formed by the Saalian ice from the NE, since they appear to have influenced flow directions during the deposition of the Haldum Formation. This formation is considered to represent a sandur formed in front of the advancing ice from the SE. In the Weichselian, prior to the formation of the Tebbestrup Formation, the landscape obviously had a varied relief. The formation which infills the lower parts of this landscape is considered as a sandur, formed in front of the advancing ice from the NE. This sandur, together with the prominent hills from the Saalian, formed the substrate for the ice from the NE. This ice modified, but did not destroy the old hills.
Deglaciation landscapes formed during the wasting of the late Middle Weichselian ice sheet in Denmark
On the basis of paleoclimatological observations the thermal regime of the Weichselian ice in the Danish area is considered in this paper to have been subpolar. The glaciological and glacial-geological consequences of this concept are discussed. Contrary to current opinion it is argued that the Weichselian ice in the Danish area formed an ice sheet containing englacial debris. Observations of plains arranged in a step-like manner, of terraces in the "tunnel"valleys connected with the plains and hanging tributary valleys, and of washboard landscapes gradually passing into plains are presented. These features are interpreted as supraglacial sandurs (down-wasting plains), elongated kettles (down-wasting valleys) and Thule-Baffin moraines formed during area-wasting of the ice sheet. The ablation deposits are considered to be partially controlled by structures in the ice sheet. The topography of the substratum of the ice sheet prior to the wasting phase may have influenced the distribution and morphology of the ablation deposits. The ablation deposits appear to form a carpet over euglacial deposits like lodgement till in considerable areas of the country. The wide occurrence of separate plains and the step-like arrangement may be the result of area-wasting influenced by climatic fluctuations.
Rhaetic to Lower Liassic palynology of the onshore south-eastern North Sea Basin
Rhaetic to Lower Liassic microfloras of gymnospermpollen, microspores and aquatic palynomorphs from outcrops and cored wells in southern Scandinavia and NW Germany are investigated. 146 groups of palynomorphs, mainly species are presented from the Danish borehole Rødby 1. Based mostly on restudy of the holotypes 24 new combinations for species/varieties occurring in Rødby 1 are proposed. One new species , Corollina zwolinskai ranging from Lower to Middle Rhaetic is described. The range of polynomorphs, mainly species are noted in the wells: Rødby 1, Maasbiüll 1 and Eitzendorf 8 and in a composite section from Scania. The following miospore zones are defined: The Corollina Enzonalasporites Zone (? Norian - Lower Rhaetic), the Ricciisporites Conbaculatisporites Zone (transition (Lower-) Middle Rhaetic), the Rhaetipollis Limbosporites Zone (Middle Rhaetic), the Riciisporites Polypodiisporites Zone (Upper Rhaetic), the Pinuspollenites Trachysporites Zone (Lias alfa 1-2) and an unnamed zone with Cerebropollenites macroverrucosus (Lias alfa 3 to beta to ?, upper boundary not defined). Within the Corollina Enzonalasporites Zone the following subzones are defined: The Corollina Porcellispora Subzone, the Granuloperculatipolis Subzone and above the Enzonalasporites Conbaculatisporites Subzone. The two latter subzones are probably restricted to the Lower Rhaetic. The zones and subzones are used to correlate the mainly non marine deposits of Rødby 1, Scania, Poland and E. Germany with the more marine deposits of NW Germanu. In Scania the stratum typicum of the stratigraphically important species Limbosporites Lundbladi Nilsson is shown to be (Middle) Rhaetic. Unmixed Lepidopteris and Thaumatopteris macrofloras are of (Middle) Rhaetic and Lias alfa age, respectively. In E Germany the topmost "Middle Keuper" sensu Schulz is transferred to the Lower Rhaetic. In Poland the Drawno Beds are shown to be Lower Rhaetic and the Weilichowo Beds to be Middle (to Upper) Rhaetic. Rødby 1 is correlated lithostratigraphically with wells in NW Germany mainly on basis of the clay colours (red and green in the Lower Rhaetic, dark grey in the Middle Rhaetic, brown to light greenish grey in the Upper Rhaetic and dark grey in the basal Liassic). The lithostratigraphy agrees closely with the palynostratigraphy in Rødby 1.
The Søby Flora: Fossil plants from the Middle Miocene delta deposits of the Søby-Fasterholt area, Central Jutland, Denmark. Part II
The taxonomical treatment of the Søby Flora is continued in this work. The present paper is the second of 3 publications in which the flora will be described and the environmental and climatic conditions interpreted. A detailed description of leaf architecture and cuticular anatomy is given on the following species: Jugans acuminata Braun, Juglans juglandiformis (Sternb.) Giebel (no cuticle preserved), Alnus julianaeformis (Sternb.) Kvacek et Holy, Castanea atavia Unger, Liquidambar europaea A. Braun, Ulmus pyramidalis Goeppert and Salix lavateri A. Braun sensu Hantke 1954.
Late- and Post-glacial sediments in the Randers fjord area. Geochemical, sedimentological, and geoelectric investigations
Thickness and distribution of Late- and Post-glacial sediments in an Eastern Jutland valley system have been mapped, and their sedimentogenetic and diagenetic relations have been studied. The chemical and sedimentological methods used are discussed in detail. Post-glacial marine sediments formed in a tidal fjord environment are the most important deposits in the area, and it is shown that river supplies of freshwater control the salinity of the environment and were responsible for the rather high content of allochthonous material in the sediment. The marine sediments rest on Late-glacial sand, whose surface topography indicates that the valleys were formed by subglacial erosion. Local occurrences of dead ice were present at least until the Littorina sea (Atlantic) transgression. Depth conditions for Early Post-glacial peat are used to estimate the groundwater level and the course of the river Gudenå in the Continental Period. Sedimentary facies in the Atlantic Littorina sea are discussed, including salinity, tidal activity, water depth, nutrient conditions, and exchange of stagnant bottom water from the deepest parts of the fjord area. The sequence seems to have been influenced only by minor syndiagenetic and weathering processes. With the intention of providing supplementary information to that obtained from mapping of the Post-glacial sediments of the region 161 electric soundings have been carried out in the Randers fjord area. The specific resistivity of the sediments has been determined and the principle limitations of the methods applied have been investigated. Interpretation of the electric soundings has been done using a new system of computer programs. Maps showing the thickness relationships and variations in specific resistivity in the uppermost, largely Post-glacial deposits in the area have been prepared, and a map showing the location of the surface of the Danian limestone and occurrence of Tertiary clay is also presented.
Petrographic study of Danian limestone from eastern Denmark (Core Copenhagen TUBA 13)
Based on the investigations of thin sections, peel prints and X-ray radiographs, quantitative and qualitative data on the carbonate constituents of the Danian limestone from København are presented. The Danian limestone was classified according to both the petrographic nomenclature proposed by Folk (1962) and Dunham (1962) and to the occurrence of microborings. It is believed that on the basis of the results of the present study the problems concerning the wave and current intensities, as well as the relative depths of the formation of the Danian limestone, might be solved, through future petrographic investigations.
Foraminifera in Eemian deposits at Stensigmose, southern Jutland
The foraminiferal content of 57 samples from two sections in interglacial Eemian deposits of the cliff at Stensigmose, Broagerland in southern Jutland, have been investigated. Saalian glaciofluvial deposits and Eemian freshwater clay, underlying the marine sequence, were examined in order to check a contamination by reworked specimens from older deposits. The foraminiferal assemblages indicate that the marine sediments were deposited in shallow water. As the lower part of the strata was deposited, the water depth was increasing, but later on it was constantly decreasing. The lower part of the marine sequence was deposited during rising temperature conditions, reaching probably a little higher than today. Salinity was low throughout the deposition of these sediments, but higher than that of the present Baltic Sea.
Lower Jurassic biostratigraphy and ostracods of the Danish Embayment
The Lower Jurassic sequence and ostracods from 36 borings within the Danish Embayment are analysed and described. Hettangian, Sinemurian and Pliensbachian are demonstrated on the basis of extensive ostracod faunas, whilst only weak indications of Aalenian have been found. The following ostracod zones are defined as a basis for a biostratigraphical subdivision of the Lower Jurassic series in the Danish Embayment: The Ogmoconchella adenticulata - Nanacythere (Nanacythere) simplex Zone (Upper Pliensbachian). The Ogmoconchella danica Zone (Upper Sinemurian and Lower Pliensbachian). The Gramannella apostolescui - Kinkelinella (Klinglerella ) foveolata Subzone (Lower Pliensbachian). The Progonoidea reticulata Subzone (lowest Upper Sinemurian, Lias Beta-1a). The Cristacythere betzi - C. crassireticulata Zone (upper Lower Sinemurian). The Ogmoconchella aspinata Zone (Hettangian and lower Lower Sinemurian). The chronostratigraphical subdivision of the Lower Jurassic sequence in the Danish Embayment is presented, based upon the ostracod faunas described here and upon previous investigations of sediments, foraminifera and megafossils. The conditions prevailing in the basin are discussed, with descriptions of the sedimentary and faunal developments, and an evaluation of the relationships with other parts of the Northwest European area. 124 ostracod species are described; 23 are described as new, whilst 30 species which cannot be referred to any known species are described with open nomenclature owing to limited or badly preserved material. The remaining 71 species have all been described previously and are more or less well-known. The 124 species fall into 27 genera or subgenera, of which 2 genera (Pseudomacrocy pris and Cristacythere) and 1 subgenus (Nanacythere (Goniocythere)) are established as new. A subdivision is made of the described Lower Jurassic "Procytheridea". The genus Klinglerella Anderson, 1964 is placed as a subgenus under Kinkelinella Martin, 1960. Pleurifera Gramann, 1962 and Progonoidea Gramann, 1962 are regarded as independent genera placed together with Kinkelinella and the new genus Cristacythere. The family Healdiidae is regarded as being represented by only three genera in the Lower Jurassic: Ogmoconcha, Ogmoconchella and Pseudohealdia. The Ontogenetic development of the muscle scar area in Ogmoconchella is shown to be a development from a simple muscle scar of the Pseudohealdia-type to a typical Ogmoconchella-scar.ree genera in the Lower Jurassic: Ogmoconcha, Ogmoconchella and Pseudohea!dia. The Ontogenetic development of the muscle scar area in Ogmoconchella is shown to be a development from a simple muscle scar of the Pseudohea/dia-type to a typical Ogmoconchella-scar.
The Søby Flora: Fossil plants from the Middle Miocene delta deposits of the Søby-Fasterholt area, Central Jutland, Denmark. Part I
In 1969 a new Danish fossil flora was found in the Søby-Fasterholt area near Herning. The fossil flora, called the Søby Flora, is found in a clay bed at the top of the Odderup Formation. The bed is succeeded by the Middle Miocene Hodde Clay, itself overlain by Upper Miocene Glauconite Clay. The Gram Clay, containing marine fossils is found a few km further south, and forms a biostratigraphical indicator level. The fossil plants, and especially the leaves, are well preserved. This paper is the first part of the systematic description, treating the following species: Pinus thomasiana (Goepp.) Reichenbach, Taxodium dubium (Sternb.) Heer, Smilax weberi Wessel and Comptonia acutiloba Brongniart. In the present paper the reader will find the epidermis of Smilax weberi and that of Comptonia acutiloba described for the first time.
Contributions to the interpretation of the Fennoscandian Border Zone
The interpretation of reflection seismic data in the Kattegat has revealed the combined effect of tectonic movements which took place from Pre-Jurassic through recent times. A continuation of the Fennoscandian Border Zone in Scania occupies a broader belt of more deep-seated basement-related fault blocks in the Kattegat area, but fades away towards NW. A mainly Jurassic sill striking SSW from Anholt separates the Kattegat area in partially open basins of Cretaceous deposition. In the 0resund several large north-northwest striking basement-related faulted blocks appear to be associated with the tectonics of the Fennoscandian Border Zone. The most prominent features relating to the structures and the geological history of the Fennoscandian Border Zone have been outlined. Some details connected with the Pre-Quaternary outcropping for the area have been evaluated. Katholm-erratics containing "Cyrena" fossils from the Kattegat area are not of Lower Oligocene age, but from Upper Jurassic and are most probably originate from the Anholt area. One of some structural models for northwestern Europe has been advanced for verification. Parts of the Fennoscandian Border Zone have perhaps been affected by large-scale dextral fractures.
Further contributions to the knowledge of the Palaeozoic of Slagelse no. 1, Western Sealand
The material described and discussed in the present paper originates from a deep borehole near Slagelse on western Sealand. The lowermost strata have been referred to the Lower Cambrian (Sorgenfrei & Buch 1964 and C. Poulsen 1969). The present paper deals with the succession of strata between the Lower Cambrian and the Upper Permian evaporite series. The sediments in question are: Alum shale (lowermost part possibly Middle Cambrian and uppermost part possibly basal Ordovician), shales and siltstones with Lower Silurian graptolites (Table 2, p. 11), red, silty claystone (Rotliegendes?), and finally grey dolomite and dark grey, thinly laminated shale with Upper Permian gymnosperm pollen and numerous remains of a vigorous vegetation of hepatics. The description and discussion of the Silurian fossils embrace trace fossils, brachiopods, eurypterids, asteroids, graptolites (e.g. two new species of Dictyonema and a new species of Monograptus), and finally a few vertebrate scales. A study of numerous Silurian specimens of framboidal pyrite resulted in several new observations; the framboids may be explained as primitive pyritized algae. The Upper Permian microflora contains a very predominant new species of Lueckisporites; the macroflora consists exclusively of new species of hepatics referable to Jungermannites and Gessella n.g. The Palaeozoic palaeogeography and geological development of the Slagelse region is discussed in connection with a comparison with sections of some other localities.
Geochemical and sedimentological investigations of the Rosenholm Depression
The Rosenholm depression is investigated as an example of the development of the conditions of sedimentation for the Late- and Postglacial freshwater deposits in the area between Aarhus and Randers. The sequence, which in places is 12 metres thick, includes creeping soil, meltwater sand, outwash clay, Allerød-gyttja, -mould, and -peat, outwash clay and Postglacial gyttja and peat. The surface of the meltwater sand was mapped by borings; the bottom topography seems to support the assumption that the depression has had a subglacial past (tunnel valley). The Allerød-oscillation can be separated into three different facies: The NW-part has euxinic gyttja, and the SE-end has Allerød-mould and -peat. In the succeeding Postglacial lake-phase gyttja was deposited in the NW-part, while the bottom sediment in the SE-stern end (separated from the rest of the depression by a sand barrier) was composed of dy and tyrfopel. After this the basin continued to be divided into two parts until peat covered the whole area. Measurements of acidity (pH) and redoxpotential (Eh) indicate that the whole series of layers are undergoing decomposition at the present time.
A Lower Carboniferous microflora from the Ørslev No. 1 borehole, island of Falster, Denmark
A miospore assemblage composing 80 species is recorded from Lower Carboniferous strata in the Ørslev No. 1 borehole, island of Falster, Denmark. 45 spore types are referred to known species and 6 are proposed as new. The remaining forms are described with open nomenclature. The present knowledge of the Lower Carboniferous microfloras and their distribution within NW. Europe is briefly summarized. It is shown, that the Ørslev assemblage has a composition very close to that of the Lycospora pusilla (Pu) Zone assemblages from Scotland and northern England. Outside NW. Europe it shows affinities to spore assemblages described from eastern Canada and the south-west areas of the Soviet Union. The stratigraphical implications of these correlations are discussed. By means of indirect correlations the spore containing beds are referred to the Belgian Upper Tournaisian or Lower Viséan.
Lower Carboniferous Foraminiferal Faunas of the Boring Ørslev No. 1, Island of Falster, Denmark
Lower Carboniferous foraminifera from a 1700' thick series of limestone, marlstone, and claystone in the boring Ørslev No. 1 are studied. 48 forms are described. 17 of these are identified to species, two of which are established as new species and two as new subspecies, namely Lituotubella glomospiroides minima n. subsp., Septabrunsiina spissusvoluta n. sp., Endothyra danica n. sp., and E. michoti spinata n. subsp. The remaining 31 forms are given with open nomenclature; nine of these are morphospecies, provisionally referred to already known species. The study and description of the foraminifera are based on the external morphology of the tests and on defined sections of the tests. On the basis of the biostratigraphy, the deposits are referred to the Lower and Middle (?) Visean. The interval 6740'-6945', which has a fauna dominated by the family Ozawainellidae, may probably be correlated with certain parts of the Russian and the Belgian Middle Visean (Visean 2), while the interval 6945'-8440' correlates with the Lower Visean in Belgium (Visean 1) on the basis of its faunas, characterized by the genus Endothyra.
K/Ar Age Determinations from the Precambrian of Denmark
K/Ar age determinations on granites and pegmatite from the island of Bornholm give results between 1255 and 1340 m.y. Ages between 1300 and 1500 m.y. are common in Scandinavia, Russia and North America. They are believed to represent a period of anorogenic plutonic activity. K/Ar age determinations on core samples from deep tests made in Jutland and on Fyn give acceptable results between 800 and 900 m.y. for the crystalline basement. This indicates a relation to the 900-1200 m.y. orogenic episode recorded in Southern Norway and in Central Europe.
The Relative Pollen Productivity and Pollen Representation of North European Trees, and Correction Factors for Tree Pollen Spectra. Determined by Surface Pollen Analyses from Forests
The present work deals primarily with a determination of the relative pollen productivity of various trees from North Europe by means of their representation in pollen analyses of surface samples from forests, with the aim to calculate correction factors for pollen diagrams. Surface samples from 2 forests in Denmark were examined. The forest composition was determined by tree crown areas and tree basal areas in small sample plots. The relation of the tree crown areas to the tree basal areas was determined for the various tree species, and the data for crown area composition, basal area composition and tree frequency were compared. The pollen preservation in the various surface samples was examined. Data on wind conditions are mentioned in the chapter about pollen dispersal in the forest, and the various modes of pollen transfer are discussed. The amount of exotic pollen in the samples is used as a calculation basis for the tree pollen frequencies, and the occurrence and composition of the exotic pollen is discussed. The relationship of the forest composition to the tree pollen deposition is discussed. Pollen deposition and pollen productivity is expressed by a regression equation. The relative pollen productivity of the tree species is expressed in relation to a reference species, in the present case Fagus silvatica. Pollen representation and relative pollen representation are determined by a comparison of pollen percentages with percentages for areal frequency. Pollen productivity factors, pollen representation and correction factors were determined for Danish species of Quercus, Betula, Alnus, Carpinus, Ulmus, Fagus, Tilia and Fraxinus by means of the pollen frequencies in the surface samples. Corrected pollen percentages were compared with the tree areal percentages in the sample plots. Data for the pollen frequencies of forest plants other than the trees are presented. The data on trees from Denmark are compared with other data from Northern Europe, and correction factors were calculated for species of Pinus, Picea and Abies. Tree pollen spectra from outside the forest are discussed and the relative pollen representation is calculated. The present calculations of the relative pollen productivity of the trees are compared with previous estimates, and the application of the correction factors to pollen diagrams is discussed.
Ostracod Biostratigraphy of the Kimmeridgian in Northern and Western Europe
The chronostratigraphical type profile of the Kimmeridgian of Dorset is subdivided biostratigraphically into five ostracod zones. Six other areas in Northern and Western Europe with Kimmeridgian ostracods are examined. The species are listed, counted, and examined in relation to the zones of the type Kimmeridgian. In the Lower Kimmeridgian the ostracod faunas bear the impression of a relatively uniform composition between the examined areas. In the Upper Kimmeridgian two different faunal regions are developed. In the North Sea Basin in the North Western Danish Embayment and in Dorset relatively uniform faunas occur, separated from other, again rather uniform faunas occuring in the Mid-European Region, from Northwestern Poland and Scania to the Paris Basin. Stratigraphically important are species of the genera Galliaecytheridea, Mandelstamia, and Macrodentina. 19 species are given diagnoses. Two new subgenera and seven new species are established.
Megaspores and Ostracods from the Rhaeto-Liassic Section in the Boring Rødby No. 1, Southern Denmark
Megaspores and ostracods from the Rhaeto-Liassic section of the boring Rødby No. 1 are studied. 15 species of megas pores are described, of which two are new: Bacutriletes reticuliferus n. sp. and Horstisporires sp. (Type No. 5). Another one, Macrosporites cf. brasserti (Stach & Zerndt) is a derived carboniferous form. Two assemblage zones are defined, namely the T. pinguis Assemblage Zone(below, Rhaetic) and the N. hopliticus Assemblage Zone (above, Lower Lias). 10 species of ostracods from the Lias section are described, of which two are new: Procyrheridea mediorericulata n. sp. and Stenestroemia ? roedbyensis n. sp., and five have open nomenclature. The ostracods from the Rhaetic are registered but not described. The O. aspinata Assemblage Zone (Lower Lias) is defined. The Rhacto-Liassic section is divided chronostratigraphically in Middle Rhaetic, Upper Rhaetic, Lower Hettangian, Upper Hettangian, and ? Lower Sinemurian.
The Lower Cambrian from Slagelse no.1, Western Sealand
The material described and discussed in the present paper originates from a deep borehole near Slagelse on western Sealand. Quartzitic beds, probably belonging to the Mobergella holsti zone, are followed by silty shale with Lower Cambrian fossils. The fauna is represented by the following genera and species: Parahyolithes danicus n.g. et n.sp., Kjerulfia selandica n.sp., Holmia kjerulfi (Linnarsson)?, Ellipsostrenua conifrons n.sp., Torellella holmi Kiær, Torellella laevigata (Linnarsson), and indeterminable fragments of olenellid trilobites. The fossiliferous silty shale is referred to the Holmia kjerulfi zone. Finally, the eventual palaeogeographic significance of the material is discussed.
Molluscan Faunas and Biostratigraphy of the Marine Younger Miocene Formations in Denmark. Part II: Palaeontology
In this volume there are descriptions of 45 pelecypod species or subspecies, 5 scaphopod species, 107 gastropod species or subspecies, and 3 pteropod species from the marine Younger Miocene formations in Denmark. Most of the species have been pictured on a total of 27 plates. The following four species have been described as new ones: Solariella jutensis, Asthenotoma ravni, Diaphana moerchi, Spiratella gramensis. In Part I of the present work (published in 1966), furthermore, the following three species from the formations investigated were described as new ones: Astarte (Goodallia) esbjergensis, Hinia slieswicia, and Neoguraleus Sæthensis. These three species and Siphonodentalium cf. lobatum (Sowerby) are important species which on account of their importance for the biostratigraphical discussion had to be mentioned in Part I. Apart from the species which are considered new ones, all the other molluscan species have been described before. However, many species have only been mentioned rather briefly in early palaeontological works. For uniformity's and documentation's sake the species have been described in great detail. Exceptions are some of the species mentioned previously (Rasmussen 1956). Some of the species pictured in the work of 1956 have not been pictured in the present work. In the case of some species, however, there seemed to be reason for offering a new and better picture.
Rhaetic-Jurassic-Lower Cretaceous Sediments in the Danish Embayment (A Heavy-Mineral Study)
The Danish Embayment is a major structural feature in the deeper part of the Danish underground (map, fig. 1). The subject of this study is the Rhaetic, Jurassic and Lower Cretaceous sediments in deep borings in this area. The object of the investigation has been to throw light on the origin of these sediments; the study deals with the lithology and petrography of the beds, and in particular the heavy mineral distribution. For each boring the observations and analyses have been compiled in the form of a profile diagram (Plates II-XVII); the lithology is shown by means of a columnar section accompanied by descriptions and Schlumberger curves; the analytical data for carbonate content, grain size distribution and also the quantitative mineral distribution in the grain size fraction 75-250 μ are shown alongside. The Rhaetic, Jurassic and Lower Cretaceous sequence is up to ca. 2 km thick. It consists essentially of rather dark marine clay deposits alternating with lighter, partly non-marine sand deposits. A simplified representation of the distribution of the two main facies in the well section (fig. 3) forms the basis of an account in which the lithological development of the sequence is reviewed. In this account the sequence is subdivided into 11 stratigraphical formations (Table I). The account of the mineral content of the sediments starts with comments on the various minerals and mineral groups, after which the main features in the mineral distribution are described. In the area examined certain regions can be distinguished whose mineral assemblage does indeed vary upwards through the sequence, but which nevertheless retain their individuality on the whole. The reason for this regional development is discussed. The major differences from region to region are probably due to the sedimentary material having been brought from various areas of denudation; the sediments are evidently mainly derived from Fennoscandia, but the Ringkobing-Fyn High is also considered to have supplied material. Some of the marked changes in the mineral assemblage are, however, interpreted as being the result of more intense weathering and redeposition of sediments determined by alterations in the palaeogeography of the area. A third controlling factor is diagenesis, which in a few special cases seems to have altered the original mineral assemblage radically. Finally, the results of the lithological and petrographical investigations are considered collectively in a review of the geological development of the depositional area. This account, which is introduced with comments on the structure of the basin and its relations to the surrounding area, is based on five palaeogeographical maps where the extent of the depositional area, the distribution of the clay and sand facies, and the main features of the heavy-mineral distribution are sketched for the Rhaetic, Lias, Dogger, Malm and Lower Cretaceous respectively. It emerges that considerable changes have taken place in the palaeogeography of the area from time to time. Despite this a certain uniformity can be traced in the sedimentological-palaeogeographical development in the Danish Embayment from the Rhaetic to the close of the Lower Cretaceous; it was first when the widespread Albian marine transgression took place that fundamental changes occurred.
The Ostracod Genus Dicrorygma POAG 1962 from Upper Jurassic and Lower Cretaceous
Representatives of the subgenus Dicrorygma Poag are found in Lower Cretaceous beds in Texas, England, and Denmark. Two new Lower Cretaceous species have been described from England and Denmark, respectively. Besides, an ostracod closely related to the English species has been described from Danish beds. Species of Dicrorygma (Orthorygma) nov. subgen. occur in beds of the Kimmeridgian, Portlandian, and Purbeckian Ages from Denmark. Frequent occurrences of the species in the Purbeckian beds indicate marine ingressions in these otherwise brackish deposits. A number of formerly described Upper Jurassic species from NW. Europe are considered to belong to the genus Dicrorygma. Three new Upper Jurassic species are described.
Differential pollen dispersion and the interpretation of pollen diagrams. With a contribution to the interpretation of the elm fall
Pollen grains are liberated into the air in vast quantities. They are carried by air movements to the stigmas of the flowers, or eventually deposited on the ground and on lake surfaces. This transfer is a complex physical process, which can only be understood from a detailed knowledge of how and when pollen grains are released into the air, how they are transported by air currents in and above forests and over lakes and bogs, and how they finally settle out of the air and become incorporated in various deposits. Being dependent on transfer by air currents, the degree of dispersion will vary considerably with the size of the pollen grains, with the time of the year in which they are emitted, and with the physical structure of the vegetation. Pollen records preserved in lake and bog deposits must therefore be expected to give a more complex reflection of the vegetation around basins than is usually assumed in pollen analysis.
Molluscan Faunas and Biostratigraphy of the Marine Younger Miocene Formations in Denmark. Part I: Geology and Biostratigraphy
The result of biostratigraphical investigations into the marine Younger Miocene formations in Denmark on the basis of the molluscan faunas shows the presence of six assemblage zones, distributed by two on the older formation, viz. the Hodde Formation, and four on the younger formation, viz. the Gram Formation: Upper Miocene (Gram Formation): The Nassa slieswicia zone The Astarte reimersi - Nuculana pygmaea zone The Astarte reimersi - Goodallia esbjergensis zone The Astarte vetula zone Late Middle Miocene (Hodde Formation): The Nassa fuchsi - Limopsis lamellata zone The Nassa cimbrica - Aquilofusus festivus zone. In Denmark all the zones have only been recorded from West and Central Jutland and North Slesvig. So far they all seem to be distributed over the same region, except for the Nassa slieswicia zone, which has so far been recorded only from the region farthest south, close to the Danish-German frontier. The marine Younger Miocene formations in Denmark include an unbroken, at least 35 m. thick series of clay, consisting at the bottom of Hodde Clay (belonging to the Hodde Formation), above that of Glauconite Clay, and at the top of Gram Clay (the last two belonging to the Gram Formation). Fairly homogeneous bottom conditions make it possible to follow the evolution of a few species from the Hodde Clay to the uppermost parts of the Gram Clay. The basis of the investigations is partly collected, partly sorted-out material from about 90 localities scattered over the whole area of distribution. The most important basis, however, is a borehole at Gram in North Slesvig, where the complete series of clay was penetrated, and a borehole at Sæd, also in North Slesvig. Most of the other localities have only yielded fossils from a few assemblage zones. The geological conditions in the main part of the localities show that the series of clay to a great extent has been glacially deformed in the Quaternary Period, which has to some degree complicated the stratigraphical investigations. It has been tried to substantiate the results mentioned through rather a detailed mention of the geological conditions in each locality and through analyses of the sampled and sorted-out fauna from each locality.
Early Postglacial in Aamosen. Geological and Pollen-Analytical Investigations of Maglemosian Settlements in the West-Zealand Bog Aamosen. Vol. II: Description of Sections and Pollen-Analyses. - A Presentation of the Bog-Geological Material
The present paper presents sediment descriptions and pollen-analyses from 8 points of investigation inside the same basin (Aamosen, West-Zealand), partly from localities near the shore, partly from the central part of the basin. The investigation covers the Pre-boreal, Boreal, and the beginning of the Atlantic periods. The results of the pollen-analyses are given in tabular form, with the numerical values of the individual occurrences of the species. A discussion and interpretation of the results of the investigation are given in Vol. I of this paper.
Early Postglacial in Aamosen. Geological and Pollen-Analytical Investigations of Maglemosian Settlements in the West-Zealand Bog Aamosen. Vol. I
This paper is a discussion and interpretation of the stratigraphical and pollenanalytical material presented by the author in Vol. II of this paper: "Description of sections and pollen-analyses - A presentation of the bog-geololical material". Eight pollen diagrams from the bog Aamosen are presented, covering Preboreal, Boreal, and early Atlantic periods. On the basis of the curves of the diagrams an attempt is made to elucidate the development of the vegetation in the area. The water-level in the basin is determined from the succession of sediments and from the pollen diagrams, and a possible alternation with the oscillations of the Littorina sea is pointed out. The climate development is discussed, and a climatic oscillation in the early Atlantic period is deduced from the courses of the curves for Hedera and Viscum. Finally the habitation at the Maglemose settlement Verup 5 in Aamosen is interpreted, and individual phases of it are pollen-analytically dated.
Ostracods from the Purbeck-Wealden Beds in Bornholm
An account of the Purbeck-Wealden beds in Bornholm and a brief summary of similar beds in the Scanian-Pomeranian area are given. Two faunas are described from the Jydegaard Formation. A Cypridea-fauna is correlated with Wealden 3 in Northwest Germany. It is followed by an ostracod-assemblage, known from Northwest Germany, indicating brackish-marine environments corresponding to Wealden 3 or 4 of the German subdivision. Two new ostracod species are described. Two other faunas have moreover been identified, a brackish one in the Rabekke Formation and a brackish-marine one in the inlier at Salene. The former contains elements suggesting a Middle Purbeck age.