182 ANNtTAL, REPORT OF THE Off. Doe, 



It must be remembered that soils bear in properties aud com- 

 position distinct relation to their parent rocks, and at the same time 

 possess qualities varjiug greatly with the manner of their forma- 

 tion from the rocks. 



Let us pau^e for a moment to consider, as briefly as may be, the 

 broader geological characters of the surface rocks of Pennsylvania. 

 Dr. J. P. Lesley, former State Geologist, says: "The Allegheny 

 Mountain divides it in two nearly equal parts, popularly kuown as 

 Eastern and \\ estern Tennsylvania, entirely diherent in geological 

 character and relief surface; Western Pennsylvania belonging to 

 the Mississippi valley region, and Eastern Pennsylvania to the At- 

 lantic seaboard; Western Pennsylvania being one unbroken bitumi- 

 nous coal tield, while Eastern Pennsylvania is partly a labyrinth 

 of parallel and interlocked mountains and vallejs of the Devonian 

 and KSelurian age, and partly an open country of still older Cambrian 

 or I'rimordial, Azoic or Eundamental strata, across which runs a 

 broad, continuous belt of Triassic of Mesozoic brownstone and trap. 

 Cretacious rocks underlie a narrow strip along the Delaware river 

 below Trenton, and a mantel drift covers the surface of the whole 

 northern part of the State as far south as a line drawn nearly 

 straight from Belvedere, on the Delaware river, to Glean, on the 

 New York state line, and another line drawn nearly through Frank- 

 lin and Beaver to the Ghio state line, north of the Ohio river." 



Tbe surface thus exposed exhibits strata belonging to not less 

 than sixteen of the principal groups of geological measures, includ- 

 ing representatives of all geological ages from the earliesi to the 

 most recent. The greatest diversity in geological character is pre- 

 sented in the southeastern portion of the State, covering probably 

 40 per cent, of its area, the remainder of the surface being made up, 

 on the north, of the Catskill sandstones; in the extreme southwest, 

 of the Pittsburg coal measures, and, over the remaining central and 

 western parts of the State, of the sandstone, shale and conglomerate 

 formations more recent than the Catskill. The northern plateau 

 of the St.'itc is (!r;iin''il by tliici' Kfr<';iiiis, one (lowiii^ iioi-lli into Lnko 

 Ontario, auollier soulheasi iiilo ihf (JhcsiiiM-ake, and anollici' south- 

 west into the Ohio, disregarding tlie relatively .small territory which 

 is drained by the Delaware and its tributaries. 



Over these great areas we find soils of the three main types of 

 formation — sedentary soils, those formed by weathering aud biolog- 

 ical agencies from underlying rocks; alluvial soils, formed from 

 rocks and sedentary soils by steam transDortation, and, finally, gla- 

 cial or drift soils, formed by the transporting section of glaciers. 

 While Pennsylvania has no high mountains, the land surface is 

 so broken that there are everywhere found the conditions that favor 

 the removal of soluble matter and finely divided particles from the 

 uplands to the valley floors. In the glaciated region occur numer- 

 ous lakes of varying size and depth, many of wdiich have in the 

 course of time been shallowed and filled by silt carried from the 

 neighboring hills and by dense vegetation, so that today the beds 

 of ^hose lakes are filled with swamps and beds of peat and muck. 



The result of all these causes is a wonderful diversity of crops. 

 The agencies. State and national, which might have collected val- 

 uable information concerning these soils, have as yet accomplished 

 little. It is true that scattered through the reports of tlie Second 



