AMERICAN GEOLOGY — DECADE OF 1850—1859. 489 



probably elevated al the close <»!' ffhe Lower Silurian period and not 

 again depressed until the beginning of the period marked by the 

 deposition of the black shale (Upper Devonian). Later, in 1859, Sat* 

 ford pointed out the fact that the crinoidal and variegated marbles 

 and ferruginous limestones of eastern Tennessee were originally 

 deposited in the form of long, narrow belts, .stretching in a northeast 

 and southwest direction entirely across the State. This striking fea- 

 ture he accounted for on the supposition that the materials were 

 deposited in long and narrow troughs, formed by earlier oscillations or 

 corrugations of the earth's crust, the conditions thus confirming the 

 views held by Professor Dana as to the early Silurian age of the begin- 

 nings of the Appalachian oscillations. " 



The geological survey of Pennsylvania, established under H. D. 

 Rogers in 1836, came, it will be remembered, to an untimely end in 

 1842'. Rogers being, however, unwilling to relinquish the work in its 

 unfinished condition, continued it at his own expense 

 Reports°on r the ma until he was able in L847 to make his tinal report to 

 Pennsylvania, 1858. the office of the secretary of the Commonwealth. 

 Here, for some unknown reason, the manuscript was 

 allowed to lie until the spring of 1851, when appropriations were made 

 for revising it and bringing it up to date. The appropriations were 

 continued until 1855. 



Gross mismanagement of the funds, for which, it is said, Rogers was 

 in no way responsible, prevented the publication of the report, how- 

 ever, and it was not until 1858 that it was finally issued, and then only 

 under a special contract between the author and the State, whereby 

 the latter was to furnish the sum of $16,000 and Rogers was to receive 

 1,000 copies of the book and the original manuscript. The work was 

 issued by W. Blackwood & Sons, London and Edinburgh, and J. P. 

 Lippincott & Co., of Philadelphia, and was in the form of two quarto 

 volumes containing 1,631 pages, with 23 full page plates, 18 folded 

 sheets of sections, and 778 figures and diagrams in the text. 



This was an epoch-making work, and beyond question the most 

 important document on the geology of America that had appeared up 

 to the date of issue, with the possible exception of the final reports of 

 the New York surveys, issued in 1842-43. From these it so differed, 

 however, as to be considered quite by itself. In the New York sur 



" These views are again advanced by Ulrich and Schuchert (Report of the New- 

 York State Paleontologist for 1901, pp. 633-663), who state that several folds were 

 developed <>r older ones accentuated at the close of Beekmantown (Calciferous) time. 

 Between these folds of the southern Appalachians during later Lower Siluric times 

 was the "Lenoir Basin," "containing several disconnected longitudinal folds high 

 enough to affect the direction of currents and consequently the character of the sedi- 

 ments, and, in a smaller degree, faunal distribution. ' The variegated marbles are 

 in the western or "Knoxville trough " of this basin. 



