96 THE CEYSTALLINE ROOKS OF CECIL COUNTY 



to its thinness and inability to hold water rather than to its chemical 

 composition. With greater depth, fertility increases, good water is 

 abundant, the country healthful and picturesque, and with judicious 

 fertilizing the soil becomes productive. 



The State line serpentines played an important role in the early 

 history of mining industries in Cecil county. This was due to the 

 chrome ore which they contain. 



The first discovery of chrome ore in America was made by Isaac 

 Tyson at the Bare Hills, Baltimore county, in 1827. Soon after this 

 discovery Mr. Tyson's son started the manufacture of pigment from 

 chrome ore and this industry at once brought the ore into demand. 

 A stray boulder containing ore, used to support a barrel in the 

 market-place of Belair, led to the discovery of a fresh source of the 

 material in Harford county. It was then, for the first time, noted 

 that the ore was confined to the serpentine rock and this formation 

 was accordingly traced across the Susquehanna into Cecil county, 

 and in 1828 a chrome mine was located about five miles northwest of 

 Rising Sun, which was for some time the richest known -mine in 

 America. 



The neighborhood of this deposit, the Wood's mine, has also come 

 into prominence as a collecting ground for some of the rarer minerals 

 associated with the serpentine, such as brucite, clinochlore, deweylite, 

 zaratite, picrolite, magnesite, hydromagnesite and williamsite, 1 which 

 have been found here. 



Along some of the streams of the belt there occur more or less 

 valuable deposits of chrome sand. This sand has been derived from 

 the weathering of the serpentine. The granules of the chrome ore 

 have been sorted out, transported and deposited by water. 



In the serpentine as in the mica-gneiss there are pegmatite veins. 

 Some of these are of considerable size and have been opened for the 

 feldspar. 



The veins usually, but not always, strike northeast-southwest. 



There are a number of abandoned openings for feldspar in the 

 region of Goat Hill and just to the north of the State line. One and 



1 This locality is designated "Texas," Lancaster Co., Pa. in Dana's Mineralog-y. 



