62 Scientific Intelligence. 



tain mica and are not schistose ; the second, of light and gray fine- 

 grained gneisses with some ledges of coarse syenyte and masses of 

 tilaniferous magnetite or hematite; one bed of hematite on the 

 Cape Fear River being 40 feet thick ; the third of gneiss, hom- 

 blendic and mica schists, with some syenyte and coarse granite, 

 and a belt of chrysolyte ledges. The coarse granite of the third 

 area aifords much mica in large plates, some 20 inches across; and 

 the mining operations for the mica date back to the mound-build- 

 ers, the granite veins being " honeycombed with the ancient 

 tunnels and shafts, which were located and excavated with more 

 skill and success than the modern workers have yet attained." 



No Silurian rocks are recognized, unless on the extreme western 

 border, within what the map colors as Archaean, where, according 

 to Prof Bradley, the Lower Silurian exists as a continuation of 

 rocks of that era in Tennessee. 



The remaining formations described are the Triassic, the Cre- 

 taceous, and the Tertiary. The two Triassic areas, one on Deep 

 River and the other on Dan River, at a distance 75 to 100 miles from 

 one another, have the rocks dipping in opposite directions, those 

 of Deep Kivei', or the more eastern area, dipping southeastward 

 about 15° to 35°, and those of the other northwestward 35°. 

 Prof Kerr makes the supposition— improbable as it appears to the 

 writer — that the two are the margins of a single anticlinal that 

 once spanned the broad interval between them. The Connecticut 

 River Triassic has in general a similar southeastward dip; but 

 there is no where the opposite side of the anticlinal unless we look 

 to the New Jersey area for it, which is quite too far south to 



A large part of the volume is occupied with a chapter on 

 Economical Products of North Carolina. It embraces a large 

 amount of information on soils ; marls and fertilizers ; peat and 

 muck ; ores and mines (among which those of iron are very 

 extensive, and those of gold and copper, also, have been profitably 

 worked) ; coal (Triassic) ; graphite, and kaolin ; fire-clay, pyro- 

 phvllite, corundum, mica, and mineral waters, 



the coal field of Deep River has an area of about 300 square 

 miles. Dr. Genth obtained in an analysis of two samples, fixed 

 carbon 63-28, 70-48, volatile matter 25-74, 21-90, ash 10-14, 6-46, 

 moisture 0-84, 1-16=100. It contained sulphur 1-35, 1-02. The 

 Dan River coal afforded the same chemist 75-96 and 76-56 p. c. 

 of fixed carbon, 11-44, 13-56 of ash, the volatile matter in each 

 about 12 per cent. 



The report contains also a well-colored geological map of North 

 Carolina and several plates of fossils. 



3. Second Geological Survey of Pennsylvania. — The following 

 Reports for 1874 have recently been published by the State Board 

 of Commissioners at Harrisburg. 



Report of Progress on the Brown Hematite {Limonite) Or^ 

 Ranges of Lehigh County, with a description of the mines lying 

 between Emaus, Alburtis and Fogelsvdle ; by Feedekick Prime, 

 Jr., Assist. Geol. 74 pp. 8vo, with cuts and maps. 



