CHAPTER L. 



SURFACE GEOLOGY. 



DRIFT IN THE SECOND GEOLOGICAL DISTRICT. 



The Drift in the Second District may be divided into two classes — the 

 original Drift, composed of bowlders, gravel, etc., often found on high 

 ground in the north-western part of the district, and the modified valley 

 Drift, constituting terraces along certain streams. 



The first is a part of the general outspread of drift found throughout 

 all the northern and north-western States, and popularly known as the 

 Drift. It is found over the whole of the north-western portion of the 

 Second District, and along the hills bordering the Hocking River, some 

 distance below Lancaster. Scattered bowlders have been found in the 

 western part of Vinton county. South of the Ohio River a considerable 

 area covered with Drift is found near Ashland, Boyd county, Kentucky. 

 This was first observed by Sidney S. Lyon, of the Kentucky Geological 

 Survey. Here the Drift is pretty high in the hills, perhaps two hundred 

 feet above the low water of the Ohio. 



The eastern limit of the Drift is a line running nearly north-east and 

 south-west through Muskingum, Perry, Fairfield, and western edge of Vin- 

 ton counties. If, however, we take the Kentucky deposit into the account, 

 the line will be almost a north and south one. A single quartzite bowl- 

 der was found in Washington county, on a ridge between the Muskingum 

 River and Duck Creek, about three hundred feet above the former stream. 

 This bowlder may have been taken from the valley Drift on the banks 

 of the Muskingum, and carried to the top of the ridge by human agency. 



The bowlders of the general Drift are often found on very high ground, 

 from two hundred to three hundred feet above the principal valleys. In 

 some regions they are quite numerous, and very large. In the vicinity 

 of Lancaster they are found at elerations two hundred and fifty to three 

 hundred feet above the Hocking River. On the slopes, and near the top 

 of Mt. Pleasant (an old river hill, with bold cliffs on the western and 

 northern sides), on the high ground between Lancaster and Rushville, 

 and on the high lands on the west, which divide the waters of the Hock- 

 ing and Scioto rivers, large bowlders are abundant. Many are also 

 found in valleys which contain no modified or valley Drift. Over the 



