THE KIMMSWICK AND PLATTIN LIMESTONES OF 
NORTHEASTERN MISSOURI 
AUG. F. FOERSTE 
1. THE TERMS PLATTIN AND KIMMSWICK AS USED IN THE GEOLOGY 
OF MISSOURI 
The Champlainian or Alohawkian strata of Missouri may be 
divided into two major lithologic divisions: a lower very fine 
grained limestone in which usually no individual grains can be 
recognized even with the assistance of a lens, and an upper, dis- 
tinctly granular limestone which at some horizons is even coarsely 
granular, and more or less crystalline. 
In the Geology of Missouri, published by Prof. E. B. Branson 
in 1918 as number 15 of volume 19 of the University of Missouri 
Bulletin, the lower fine grained limestone is identified as the 
Plattin formation, while the overlying distinctly granular lime- 
stone is identified as the Kimmswick limestone, both names 
being applied in a much less restricted sense than that advocated 
at present by E. 0. Ulrich, the original author of these names. 
This will become evident on referring to plate 2 among the Cor- 
relation Tables at the close of Bassler’s Bibliographic Index of 
American Ordovician and Silurian Fossils, published in 1915; a 
part of this table is reproduced in a modified form on one of the 
following pages in section 6 of this paper. 
2. THE LITHOLOGICAL CHARACTERISTICS OF THE PLATTIN AND 
KIMMSWICK LIMESTONES 
The lower or Plattin limestone appears to have originated as 
a lime mud deposited as the result of chemical action induced by 
bacteria. During the deposition of these lime muds quiet waters 
evidently prevailed. This is shown by the frequent preserva- 
tion of even the most minute details of surface sculpture on brach- 
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