130 REPORT OF THE 



two-thirds of the whole has been derived from the'' destruction 

 of rocks within the Lower Peninsula; while a large and char- 

 acteristic portion comes from the strata in the immediate neigh- 

 borhood. The vicinity of a coal outcrop has filled the subsoil 

 with fragments of coal, which can be traced, gradually dimin- 

 ishing in abundance, for one, two or ten miles. The experienced 

 observer, however, is able to tell whether the source of the 

 materials is near or remote, for the further they have been 

 transported the more uniformly they become scattered amongst 

 the other materials, while in the immediate vicinity of the 

 outcrop the carbonaceous debris is not only more abundant but 

 contains more fine matter, and is disposed in streaks. In a simi- 

 lar manner the vicinity of a limestone formation produces a 

 calcareous soil; sandstone an arenaceous one; shale an argilla- 

 ceous one. Nowhere is the connection between the soils and 

 geological structure better shown than in Michigan. Even 

 the arboreal vegetation of the peninsula is distributed in belts 

 across the State, corresponding to the calcareous, arenaceous 

 and argillaceous belts of soil overlying the corresponding 

 rocks. 



To this epoch of the drift seems to belong a bed of lignite 

 discovered on Grand Traverse Bay, near the outlet, on the north 

 shore. The following section embraces the lignite and associa- 

 ted beds: 



F. Very fine yellow sand, 12 ft. 



E. Small boulders, pebbles and coarse sand with shells of 



Melania, and Physa, f ft. 



D. Arenaceous clay, bituminous, soft, and somewhat plas- 

 tic, . : 2 ft 



C. Lignite, dark brown, containing woody stems, (white 



cedar?) becoming below, a highly bituminous clay, . . 3 ft. 



B. Clay, dark, gray, very tough, with a few grains of sand 

 and small pebbles, a.nd considerable bituminous mat- 

 ter,. . 2^ ft. 



A. Comminuted green shale, passing above into green clay, 2 ft. 



Still lower, but not seen in this section, is a bed of green 



shale, lying above the black bituminous shale 13 ft. 



The lignite is compact, bituminous, and highly combustible. 



