Abstract
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.
Highlights
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 a few vertebrate scales
The carbon content of the Silurian framboids from Slagelse amounts to 0.6-0.8 percent; this is much less than the carbon content of younger Palaeozoic framboids, it is regarded as too much to be attributed to contamination
The Silurian framboids from Slagelse have been treated with 5-normal nitric acid without leaving any insoluble organic residuals comparable to the sacs and matrix bodies described and figured by Love (1958, 1962) and Love & Murray (1963)
Summary
As mentioned in the preface, Sorgenfrei & Buch (1964) referred about 390 m. of the penetrated strata at Slagelse to the Lower Palaeozoic. Remarks: The specimen shows much resemblance to Monograptus intermedius (Carruthers), but it differs from that species in having a more slender rhabdosome and more clearly subtriangular thecae. 7-10 contain numerous small indeterminable graptolite fragments; some of them may represent other species than the above-described ones which amount to about half the "normal graptolite community" of the Monograptus crispus zone. The superframboids occur at the bottom of the siltstones, in contact with the dark shales or nearly so These facts may lead to the following interpretation: Th e Silurian at Slagelse was deposited in a basin more or less isolated from oceanic waters. 1 shows a polished section of Silurian rock, containing a few isolated crystals of pyrite, numerous framboids , and numerous small, worm- or sausage-shaped bodies with spherical swellings at both ends, which may possibly be the microorganisms (Bacteria?) responsible for the production of hydrogen sulphide. Schopf & Blacic (19 71) for instance describe and figure Late Precambrian sph erical algae, single as well as compound, having about the same size as framboids and superframboids
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