864 THE JOURNAL OF GEOLOGY. 



siliceous organisms makes the term " radiolarian chert" more applicable. 

 Both sandstone and chert have been locally metamorphosed by the invasion 

 of eruptive rocks. The term Fourchite is doubtfully applied to an intrusive 

 sheet or sill invading the San Francisco sandstone, some portions of it con- 

 sisting of a breccia, other portions having an imperfect spheroidal structure, 

 while the main body is massive evidently representing a true sill and not an 

 interbedded flow. Bright blue amphibole, with pleochroism of glaucophane 

 is a noticeable feature. It is also remarkably free from the usual accessory 

 minerals of basic eruptive rocks. Alteration along the contact zone has 

 resulted in the development of a glaucophane schist. Serpentine which 

 occurs as a large dike traversing the island from northwest to southeast was 

 derived from a rock composed wholly or mainly of diallage and incloses 

 masses of a gray rock resembling diabase. The glaucophane schists were 

 formed from the San Francisco sandstone by metamorphism. Evidence 

 controverts the view that the radiolarian cherts (bedded jaspers) represent 

 ordinary shales silicified by regional metamorphism. The serpentine is in no 

 sense a metamorphosed sediment. The appendix contains descriptions of 

 radiolarian remains found in the chert. 



C. H. G. 



Geological Survey of Missouri. Report on the Bevier Sheet. By C. 



H. Gordon. J. E. Todd and H. A. Wheeler, contributors. 



Report on the Iron Mountain Sheet. By A. Winslow, E. 



Haworth, and F. L. Nason. 

 The above reports, issued by the Missouri Survey under the direction of 

 Arthur Winslow, State Geologist, constitute the second and third of the series 

 of sheet reports, of which the Higginsville Sheet was the first. The present 

 reports are issued in large octavo, uniform with the other publications of the 

 survey, instead of the same size as the atlas sheets, as was at first planned. 

 Each sheet comprises an area of one fourth of a square degree. The scale 

 is 1:62500, or about one inch to a mile. The topography is indicated by 

 twenty feet contours. A sheet of cross and columnar sections accompanies 

 each map. The work has evidently been carefully done. 



The Bevier sheet comprises the southwestern part of Macon county, with 

 portions of Chariton and Randolph. The topography is due entirely to stream 

 erosion. The rivers have sunk their valleys to a moderate depth in a wide 

 stretching plain, the remnants of which are still well preserved in the broad 

 inter-stream surfaces. 



The stratified rocks of the region belong to the Coal Measures series, the 

 deposits of the Middle and Lower stages being represented. Within the 

 state, however, no widely recognizable horizon separating the two has been 

 identified. The strata dip gently to the southwest, but there are local depart- 



