Reviews — Geological Survey of Missouri. 369 



The State of Missouri is divided into twenty counties, and each 

 one is treated under three principal heads, viz. the Topography, 

 Scientific and Economical Geology. The formations w^hich occur 

 in the State are the following : — 



Quaternary. — Alluvium, Bottom Praries, Bluff, and Drift. 

 Carboniferous. — Coal-measures, Ferruginous Sandstone, Archi- 

 medes, Encrinital and Chouteau Limestones. 

 Devonian. — Upper and Lower. 

 Upper Silurian. — Delthyris shale or Lower Helderberg, Niagara 



group, Cape Girardeau Limestone. 

 Lower Silurian. — Hudson river group, Trenton Limestone, Black 

 river Limestone, Magnesian Limestone series, consisting of 

 four zones of Magnesian Limestone, with alternating zones of 

 Saccharoidal and other Sandstones. 

 The Lower Silurian and Quaternary rocks are found in most of 

 the counties, the Coal-measures are not so generally distributed, 

 they are the only Palaeozoic rocks seen in Macon, occupy nearly the 

 whole of Eandolph, about one-third of Saline, probably nearly one- 

 half of Clark county, and are sparingly distributed in Morgan, 

 Warren, and Shelby counties. Igneous rocks are not abundant; 

 Granite is found in Crawford and Ste. Genevieve, in which latter 

 county Greenstone has also been noticed. The maps and sections in 

 the volume illustrate to some extent the geological descriptions in 

 the reports. J. M. 



11. — Geological Survey of Missouri. Preliminary Eeport on 

 THE Iron-Ores and Coal-fields from the Field-work of 

 1872. (New York, 1873.) 



THIS volume of more than 600 pages contains a careful and de- 

 tailed description of a portion of the economic geology of the 

 State, bearing specially on the Iron-ores and Coal-measures. The 

 first part is chiefly occupied with the distribution, description, and 

 modes of occurrence of the Iron-ores by Dr. Adolf Schmidt. Rich, 

 even the richest as Missouri is of all the States on the North 

 American continent in Iron-ores, they are very unequally distributed 

 over the State. Very little is found in the whole northern part 

 north of the fiftieth township line, and in a range of counties on the 

 western border; these districts covered by Coal-measures do not 

 contain Iron-ores in such quantities as to make them workable. 



Workable Iron-ore is found in Calloway county, north of the 

 Missouri river ; and south of it, between this river and the fortieth 

 township line, valuable deposits occur, mostly of Limonite, in 

 Franklin, Osage, Morgan, and Benton counties. By far the richest 

 portion of the State in Iron-ores is that between the 30th and 40th 

 township lines ; they abound within this zone, in the greater part of 

 the counties situated between the Mississippi on the east, and the Upper 

 Osage river on the west. The chief ores are Si^ecular iron, some- 

 times a little magnetic. Bed Hgematite, and Limonite. This part 

 also contains analyses of Fuels, Iron-ores, and Pig-irons, by MM. 



DECADE II. — VOL. 1. NO. VIII. 24 



