EAELY PALEOZOIC BEYOZOA OF THE BALTIC PROVINCES. 



Composite section of Cambrian-Early Silurian strata of Baltic Russia. 



Description of strata. 



Karly Silurian limestone. 

 Formation F. 



F 2. Borkholm limestone. 



Massive. siUceous. white limestone. 

 F 1. Lyckholm limestone (upper part). 



Gray to yellow argillaceous limestone with many 

 corals, Halysites, Calapcecia, Heliolites. etc. 



Middle Ordovician strata. 



F 1. Lyckholm limestone (lower part). 



Magnesian limestone holding Maclurea, Subulites. 

 and other gastropods closely related to American 

 Trenton species. 

 Formation E. Wesenberg limestone. 



Fosslliferous yellow shale and thin limestone inter- 

 bedded. 



Formation D. 



D 3. Wassalem beds. 



Very fossiliterous thin bedded blue limestone and 

 shale. 

 D 2. Kegel beds. 



Shaly, f ossiUferous limestone. 



D 1. Jewe beds. 



SiUceous limestone and shale holding many fossils. 



Formation C. 



C 3. Itfer limestone. 



Rather massive, siliceous limestone. 



Unusually fosslliferous bituminous shales, with 

 thin limestone bands. 



C 1. Echinospherites limestone. 



Thin bedded limestone with many trilobites and 

 cystids. 



' Obere Linsensohicht." Zone of phosphatic pebbles. 

 Formation B. 



B 3. Orthoceras (Vaginaten') limestone. 



Bather massive gray limestone crowded with ceph- 

 alopods. 

 ' Untere Linsenschloht." Zone of phosphatic pebbles. 

 B 2. Glauconite limestone. 



Thin bedded, light green to reddish Umestone, 

 sandy in the lower part. 



B 1. Glauconite sandstone. 



Unconsolidated green sand, 

 brachiopods in upper part. 



Middle Ordovician 



Dictyonema shales, A3. , , , j . 



Dark brown to reddish bituminous clays holding 

 graptolites,particularlyi)!cij/OHe))ia^a6e;i!/brai!s. 



Upper Cambrian, Ungulite sandstone, A 2. 



Unconsolidated, yellow sandstone. Upper layers 

 crowded with OboVtis apollinis. 



Lower Cambrian, blue clay and associated strata, A 1. 



Unf osslliferous sandstone correlated with the Fu- 

 cold sandstone of Sweden. 



Sandstone and clays holding Mesotiacis micTcwitzL 



Plastic blue to green clay. 



Lower sandstone with glauconite grains. 



Pre-Cambrian granite. 



