126 



UNITED STATES NATIONAL MUSEUM BULLETIN 215 



The Paleocene deposits ("S^landian," Rosenkrantz, 

 1924, p. 34), which with a complete change in facies 

 and a (minor ?) hiatus overlie the Danian limestones, 

 are composed of terrigenous detritus with some glauco- 

 nite. The Paleocene sea was a rather narrow embay- 

 ment (Gronwall and Harder, 1907). Its fauna con- 

 tained a great many marine molluscs (Ravn, 1939), 

 besides benthonic Foraminifera (Brotzen, 1948), but 

 true planktonic Foraminifera' have not been found, 

 except for some specimens which from their appearance 

 must be assumed to have been reworked from the 

 Danian rocks. Brotzen's report (1948, p. 30) of 

 Globigerinae in the Kerteminde marl of Denmark has 

 not been confirmed. {Globorotalites lobata Brotzen from 

 the Danian and S^landian beds of Denmark-Sweden 

 and in fact the entire genus Globorotalites, is not here 

 considered to be a planktonic form.) The cause of their 

 absence may well have been the influx of freshwater of 

 which the terrigenous detritus is evidence. 



In Denmark and southern Sweden, the lithostrati- 

 graphic unit which corresponds to the Danian stage is 

 the Danskekalk formation (Odum, 1935, p. 14; the name 

 simply means "Danish limestone"). Since this is in the 

 type area, the limits of the stage coincide with those of 

 the formation. The composite section given in text- 

 figure 23 is based upon the type localities at Stevns 



STAGES 



LITHOLOGY 



LOCALITIES 



TYLOCiDARlS 

 ZONES 



Selondion 



glauconitic clay 

 silt and cgl ♦6 m. 



Copenhagen 



no Tylocidaris 





Danian 





Copenhagen 

 Saltholm 



T. vexilifera 

 Schluter 



c 



1 



1 



Calcarenite with 

 chert. 30-50 m. 



minor hiatus 



Fakse, 

 Stevns 

 Klint 



T. briinnichi 

 Ravn 



Bryozoan reef Is. 

 with chert; 

 locolly corol 

 reef Is. + 66 m. 



T. abildgaordi 

 Ravn 



T. odumi 



BriJnnich Nielsen 



minor hiatus 



Stevns 

 Klint 



no Tylocidaris 



Colellutite withmorl 

 at bose, c. It'm. 



major hiatus 



MosstrleMion 



Stevns 

 Klint 



T. boltica 

 Schliiter 



White chalk with 

 chert. + 20 m. 



Figure 23. — Composite section through the Danian stage of east Den- 

 mark (adapted from A. Rosenkrantz, 1937, p. 201; only the more 

 important localities are listed). 



Klint and Fakse combined with occurrences in or near 

 Copenhagen (Rosenkrantz, 1937, p. 201). 



Biostratigraphy 



A few remarks on the planktonics of the Danian 

 stage of Sweden have been published by Munthe (1896) 

 and Brotzen (1940, 1945, 1948), but only the important 

 articles by Bronnimann (1953) and Reichel (1953) give 

 any information on the occurrence of these organisms 



in the type Danian. Reichel, who examined two pieces 

 of limestone from Fakse, seems to have been the first 

 to correlate, in a general way, the type Danian with 

 the zone of small Globigerinae which in the Tethys area 

 commonly occurs between the Globotruncana assemblage 

 of undoubted Maestrichtian age and the Globigerina- 

 Globorotalia assemblage of assmned Paleocene age (see 

 also Z. Reiss (1952, 1954, 1955), J. Schweighauser 

 (1953, p. 28), S. E. Nakkady (1955), Bettenstaedt 

 and Wicher (1956, pp. 501, 514-515), and others). 

 Bronnimann (1953) lists the foUowing Globigerina 

 species which he found in a sample of Danian cocco- 

 lithic limestone from Daubjerg in northwest Denmark 

 and which also occiu* in the Lizard Springs formation of 

 Trinidad, B. W. I.: G. pseudobudoides Plummer, G. 

 trUoculinoides Plummer, G. linaperta Finlay, G. horni- 

 brooki Bronnimann, G. stainjorthi Bronnimann, G. 

 daubjergensis Bronnimann, and G. compressa Plummer 

 (another sample from Hjerm contained only two poorly 

 preserved species) . 



Globigerinae occur throughout the Danian stage, 

 whereby the theory that the Danian sea was at one 

 time transformed into a completely enclosed basin 

 seems to have been refuted (Ravn, 1939, p. 23, and 

 others). In the Danian of eastern Denmark, the only 

 horizons in which Globigerinae are even fairly abundant 

 are, however, the base of the zone of Tylocidaris odumi 

 and the greater part of the zone of Tylocidaris veziiifera 

 (the latter occurrence has already been observed by 

 Brotzen, 1940). Even within these zones, only a few 

 samples have yielded well-preserved tests and it has 

 therefore been rather difi&cult to procure enough materi- 

 al for the following analysis. 



Although the underlying White Chalk of Maestrich- 

 tian age is characterized by the abundant occurrence of 

 Rugoglobigerina, "Globigerinella," Pseudotextularia, stri- 

 ated Guembelinae, and, in certain strata, GlobotruncarM 

 (s. 1.), the only planktonics to occur in the type Danian 

 are small Guembelinae and Globigerinae, of which only 

 the latter will receive fm-ther attention in the present 

 article. The change from one faimizone to the other 

 is very abrupt and occurs at the hiatus between the 

 White Chalk and the Danskekalk formation (text-fig. 

 23). The fact that the basal few iuches of the 

 Danskekalk formation contain occasional specimens 

 (presumably reworked) of Rugoglobigerina and "Glo- 

 bigerinella" does not alter the impression of a funda- 

 mental difference between the two deposits (see also 

 Troelsen, 1955a). On the evidence of the planktonic 

 Foraminifera, the present writer is therefore inclined 

 to agree with those who place the Danian stage in the 

 Cenozoic. 



For the present analysis the writer has endeavored to 

 procure samples from the type localities of the Danian 

 stage and from all the major fossil zones. Only the 

 samples representing the zone of Tylocidaris vexilifera 

 had of necessity to be collected outside the type 

 localities since this zone is not represented there. In 

 order to avoid bias, only samples in which even the 

 smallest Foraminifera were well preserved and identi- 



