MARYLAND GEOLOGICAL SURVEY 95 



The ground is strewn with these rusty yellow silicious iron-stones, 

 which exhibit more or less of a honey-comb structure due to a finally 

 complete removal of the magnesian silicate. 



Serpentine is always accompanied and is sometimes completely 

 replaced by a final alteration product talc (steatite, soapstone). 

 Soapstones are therefore also of frequent occurrence in serpentine 

 areas. 



With the serpentines are also associated amphibole schists contain- 

 ing asbestos, tremolite, anthophyllite, actinolite or chlorite, and rep- 

 resenting the metamorphism of pyroxenites. All these associated 

 types, the original peridotites and pyroxenites, the serpentines repre- 

 senting one phase of metamorphism, the amphibolites representing 

 another phase of metamorphism, the soapstones and the iron-stones 

 representing an extreme phase of alteration, are considered a geologic 

 unit and mapped as a single formation. 



The soil to which they give rise and the aspect of the country 

 underlain by them is most distinctive. The soil is known by the 

 farmers as the " honey-comb-rock soil " and its sterility is recognized 

 by them. Where the rock comes close to the surface, either out- 

 cropping or with scanty covering, as is often the case, the soil is the 

 color of the rock, yellowish-green. Where the accumulation of a 

 greater depth of mantle-rock has permitted chemical processes to take 

 place, the soil, rich in oxidized iron, possesses an intensely red color. 



The main serpentine belt is locally known as " the barrens " and 

 strikingly merits that name. At the border of the serpentine belt the 

 aspect of the country alters abruptly. One leaves behind a prosper- 

 ous and pleasing agricultural region and enters a wild and desolate 

 district supporting a scanty vegetation. Dwarfed white pines, cedars 

 and the cat-brier thinly clothe the rugged hills and render travel 

 across country difficult. 



Prom the summit of hills within or adjoining " the barrens " the 

 distribution of the serpentine can be traced by the peculiar character 

 of the vegetation it supports. (See Plate IX, Fig. 1.) 



The barrens are sparsely settled and the houses small and poor, 

 for the most part. The comparative sterility of the soil may be due 



