AMERICAN GEOLOGY DECADE OE 1830-1839. 34 ( .) 



form of mi octavo volume of 188 pages in 1841, the geological forma- 

 tions of the State were divided into (1) Primary, (2) Upper Secondary, 

 (3) Tertiary, and (4) Recent. The geographical distribution and litho- 

 logical character of each was given in detail. The Primary included 

 gneiss, feldspathean rocks (traps), limestone, serpentine, and granite; 

 the Upper Secondary, the Red Clay Formation and the Green Sand 

 Formation. The Tertiary he divided into 

 the northern Tertiary, the southern Terti- 

 ary, the yellow-clay formation of Appo- 

 quinimink Hundred, and the intermediate 

 clays and sands. The Recent Formations 

 were divided into the lower clays, the upper 

 sands, and the river deposits. Attention 

 was given to the Greenland and to other 

 questions of economic interest. 



The report as a whole represents the 

 patient attempt of a man unversed in the 

 broader problems of geology who wrote 

 down only what he saw and thought he 



i i i tt' i ,i ,i I'm.. MO. — James Curtis Booth. 



understood. His remarks on the weather- 

 ing of rocks are perhaps the most striking. The entire cost of this 

 survey to the State was $3,000, of which sum Booth received §2,000 

 for his two years' work, the remainder going to defray cost of publi- 

 cation of the report and various incidentals. 



In 1837 there was organized the first State geological survey of 



Indiana, Dr. D. D. Owen, who had served as an assistant on the survey of 



Tennessee under Gerard Troost, being appointed State geologist. The 



life of the survey was limited to two years, and two 



D. D. Owen's J . 



survey of Indiana, reports were rendered, one of 34 paeres, bearing- date 



1837-39. / ' . & , 



of 1838, and one of 54 pages, bearing date of 1839. a 

 The essential similarity of the formations of Indiana with those of 

 Ohio was recognized. The lowest lying, oldest rock, called blue 

 limestone, 6 which he regarded as the equivalent of the Lower Silu- 

 rian limestones of Europe, was described as forming, near the com- 

 mon boundary line between Indiana and Ohio, a kind of backbone 

 which dipped gently in east and west directions, gradually disappear- 

 ing in both States beneath a series of overlapping strata which, with 

 one exception, have uniform characteristics. Here for the second 

 time (see p. 333) is recognized the presence of the low swell known 

 later as the Cincinnati anticline or uplift, which was subsequently 

 identified by Newberry and Safford as a Middle Silurian emergence. 

 This blue limestone was overlain by another limestone, regarded as the 



" Reprints of these appeared under date of 1859. 



''This is the equivalent of the Cincinnatian division of the Lower Silurian of 

 recent writers. 



