592 A. W. GRABAU LOWER ORDOVICIC FORMATIONS 



not wanting indications of a possible hiatus between the Ceratopyge beds 

 and the Upper Cambric strata. One such we were enabled to study at 

 Oedegarden, near Ekedalen, in Westergotland, under the guidance of 

 Prof. Carl Wiman, of Upsala. The section herewith given is taken from 

 my field notes and represents the Ceratopyge limestone— here intimately 

 associated with, and indistinguishable from, the Planilimbata limestone — 

 resting on the fetid limestone of the Olenus-bearing Alum shale series 

 (Upper Cambric). The fetid limestone contains Peltura and Sphaeroph- 

 thalmus, and its upper surface is characterized by corrosion hollows 

 which are often several centimeters deep, and are filled. by the glauconitic 

 Ceratopyge limestone. The two are so firmly united that it was possible 

 to remove specimens showing both beds. 26 The base of the Ceratopyge 

 limestone is characterized by brown phosphate nodules, which contain 

 fossils of the underlying Stinkkalk and represent altered fragments of 

 the same. 



The Dictyonema shales are here wanting, as well as the zones of Acero- 

 care and Parabolina lieres, which in Scania have a thickness of 5 meters, 

 and this and the corrosion grooves suggest temporary exposure of the 

 Upper Cambric beds. I doubt, however, if this exposure was a long one; 

 it represents more likely one of those numerous small oscillatory move- 

 ments which seem to have characterized certain portions of the old land 

 of Cambric and Ordovicic time, on the borders of which the strata of this 

 period were deposited. 



The Ceratopyge beds seem to be wholly wanting in Esthonia, where the 

 Dictyonema shale is also occasionally absent. It, or the Ungulite sand- 

 stone below it, is followed by glauconitic sandstone, which Lamanski 

 designates as Division B I of his series. This reaches its greatest thick- 

 ness of 5.5 meters in the western area at Baltic Port, where the rock 

 consists of rounded quartz and glauconite grains with fragments of crys- 

 talline rock and some bituminous shale pieces. Eastward it becomes 

 thinner and more clayey, being mostly clay with intercalated sandy loam 

 east of Saint Petersburg. 



The contact between the base of the glauconite sand and the top of the 

 Dictyonema shale is always sharp, since there is a slight erosion hiatus 

 between them, as indicated by evidence of erosion in the shale and the 



26 According to Michalsky, this is the usual relation when glauconite rests on lime- 

 stones. It has been noted in the Schratten Kalk of Switzerland and in the Jurassic 

 limestone near Regenshurg, in addition to the Ceratopyge horizon of Sweden. (The 

 holes are often as if made with an augur and filled with glauconite. Cong. Geol. Int. 

 Compt. Rend., sesion Stockholm, also Andersen, Bull. Geol. Inst. Univ. Upsala.) The 

 Regenshurg occurrence I was enabled to study with some care. Here the contact is 

 between the Regenshurg greensand of Cenomanian age and the Kehlheim limestone of 

 Upper Jurassic age. 



