UTRECHT MICROPALEONTOLOGICAL BUllETINS

Figure 11 summarizes the biozonations of part of the generalized lithostratigraphic
column of Sweden, covering the "Olenid shale", the "Diety onema
shale", the "Ceratopyge shale", the "Ceratopyge limestone", the "Planilimbata
limestone" and the "Limbata limestone" of the literature (compare
chart I).
In Oland the "Olenid shale", the "Dictyonema shale" and the "Ceratopyge
shale" (together covering the Djupvik Formation of this paper) were investigated
biostratigraphic ally by Holm (1882), Tullberg (1882), Westergar,d
(1922,1947) and Hadding (1927,1932).
From Kopingsklint and from the coast S.W. of Djupvik, Westergard
(1922) described two rock-sequences and their faunal contents. In figures 12
and 13 Westergard's lithostratigraphic classification, the lithostratigraphic
classification used in this paper, the faunas and their probable position in the
Swedish biozonation (fig. 11) were put in juxtaposition. In a comparable
way, Holm's (1882) description of a rock-sequence near Horns Udde is
treated in figure 14.
Tjernik (1956) studied the Lower Ordovician of Sweden, together with its
trilobite- and graptolite-zonation. Figures 16, 17 and 18 summarize the
lithostratigraphic units and their biozonation, as he recognized them at
Kopingsklint, Aleklinta and Horns Udde. To these, the lithostratigraphic and
biostratigraphic classifications used in this paper have been added for comparison.
Neither from the remaining part of the Bruddesta Formation, nor from
the Horns Udde Formation, an earlier detailed biozonation is known to the
author.
Figures 12, 13, 14 and 16, 17 and 18 clearly show that the previously
used biozonations of the strata of N.W. bland, lack the detail for an
adequate chronostratigraphic positioning of the lithostratigraphic units recognized
in this paper. A more detailed biozonation will be attempted, based
on conodonts. Lindstrom found them in enormous quantities in the Lower