.insTK.ic'fs 653 



Francisco Peninsula, wliicli includes studies of the Franciscan series, 

 the Serpentine, tlie Tejon sandstone, the Merced series, the Terrace 

 formations and the diastrophic record. 



The IMarquette iron-bearing district of Michigan is treated in a 

 preliminarv report bv Van Hise and Bayley, with a chapter upon the 

 Republic trough by H. L. Smyth. The Basement Complex, the Lower 

 Marquette and the Clarksburg formations are treated with considerable 

 detail. 



The Origin and Relations of the Central Maryland Granites is 

 treated by C. R. Keyes after an important introductory chapter upon 

 the General Relations of the Granite Rocks in the Middle Atlantic 

 Piedmont Plateau, by the late Professor G. H. Williams. 



H. F. B. 



Notes Concerning a Peculiarly Marked Sedimentary Rock. By Dr. J. E. 

 Talmage, President and Deseret Professor of Geology, University 

 of Utah. Published in pamphlet form, with five plates, reprinted 

 from the Utah University Quarterly. 

 The author describes and illustrates a fine-grained argillaceous 

 sandstone, bearing peculiar surface markings consisting mostly of 

 straight lines intersecting at right angles with almost mathematical 

 precision. The deposit was examined by the writer in place, and an 

 extensive collection of specimens was made under his direction by the 

 " Utah University and Deseret Museum Expedition of 1895." The for- 

 mation consists of undisturbed sedimentary deposit, referred to Trias or 

 Jura-Trias age, and occupies a relatively low table land between the 

 Kaiparowitz and the Paria plateaus on the north of the Colorado River 

 near Glen Canyon, Arizona. The bed of marked rock is almost two 

 feet thick, and lies conformably between deposits of coarser sandstone, 

 which show none of the rectilinear markings. While the most regular 

 arrangement of the marks appears on slabs with perfectly fiat surfaces, 

 yet the rectilinear intersections are plainly shown on warped and rip- 

 ple-marked surfaces. The lines are so regular as to suggest the possi- 

 bility of human instrumentality when hand specimens only are exam- 

 ined. The author has performed a number of experiments to test the 

 theory of sun-crack or shrinkage-fissure origin, with negative results ; 

 but succeeded in producing marks similar in appearance through the 

 formation of ice-crystals on mud formed from the pulverized stone. 

 Then by pouring on such mud concentrated natural brine from the 



