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Biennial Report of the State Geologist, Missouri Bureau of Geology 

 and Mines. 

 The part of this report of general interest is the last chapter, a report 

 on the mineral resources of the state. The value of the total output in 

 1907 is estimated at over $41,000,000, of which lead and zinc make up over 

 $18,000,000. This is the largest in the history of the state. The growth 

 of the output has been steady, and will doubtless continue. E. R. L. 



The Geology of Pike County. By R. R. Rowley. Missouri Bureau 

 of Geology and Mines. Vol. VIII, 2d series. 

 Pike County is located in the eastern part of Missouri, bordering the 

 Mississippi River. It is essentially a region of hills, streams, and valleys 

 in the eastern part, with more or less level prairie plateau in the west. 

 The rocks consist of alternating limestones and shales, Ordovician to 

 Pennsylvanian in age. They are practically horizontal and are, as a rule, 

 highly fossiliferous. A number of species are described and figured, 

 especially the fauna of the Louisiana (Lower Mississippian) limestone and 

 the tribolites from the Ordovician. A short resume would add greatly 

 to the value of the report. E. R. L. 



Report of Topographic and Geologic Survey Commission of Pennsyl- 

 vania, igo6-igo8. 



The work of this commission is done in co-operation with the United 

 States Geological Survey and the results published by the National Survey. 

 The greater part of the present report is under the heading "Appendix 

 E, Report of Progress of Co-operative Geological Survey." Of this the 

 first part is a summary of geological work done in Pennsylvania and a 

 review of the general geology of the state. Then follows a more detailed 

 study of the southwestern part of the state. Except a small dike of peri- 

 dotite which is reported from one of the mines near Masontown, Fayette 

 Co., the rocks are all Paleozoic sedimentaries, Ordovician to Permian, 

 with a covering of glacial and glacio-fiuvial deposits in the southern part 

 of the district. 



Special attention is given to the economic resources, of which coal is 

 by far the most important. Pennsylvania produces more coal than any 

 other state or country in the world excepting Great Britain. In 1907 the 

 coal mined was valued at nearly $320,000,000, over half of which was anthra- 

 cite. Petroleum and gas, clay, and limestone products are also of great 

 importance. E. R. L. 



