510 



UNITED STATES MINERAL RESOURCES 



All humus and reed-sedge and some moss peat 

 production is from surface pits, and most operations 

 use conventional types of excavating and earth- 

 moving machinery, including bulldozers, draglines, 

 and front-end loaders in drained bogs, and clamshells 

 and dredges for submerged deposits. Use of spe- 

 cialized machines for cutting sphagnum moss is 

 replacing the ancient practice of hand cutting sphag- 

 num moss blocks, especially in large bogs in Maine. 

 Peat is prepared for sale by shredding and screen- 

 ing; some is dried artificially. 



Before 1955, most domestic peat was sold locally 



in bulk, but since then, large quantities have been 

 packaged and distributed to all parts of the United 

 States. Prices of domestic peat vary greatly; in 

 general, the sales value depends chiefly on the type 

 of peat, the degree of processing, and whether the 

 peat is sold in bulk or packages. In 1970, the aver- 

 age value of bulk peat was $8.13 per ton, $0.46 more 

 than the average value of bulk peat sold in 1969. 

 Packaged peat, however, declined in average value 

 from $17.60 per ton in 1969 to $14.51 per ton in 

 1970. Commercial sales of peat in the United States 

 in 1970 are shown in table 102. 



Table 102. — Commercial sales of peat produced in the United States in 1970, by use 



[Source: U.S. Bur. Mines; Sheridan, 1971b] 



In bulk In packages Total ^ 



Quantity Quantity Quantity 



Use (Short tons, Value (Short tons. Value (Short tons. Value 



thousands) (thousands) thousands) (thousands) thousands) (thousands) 



Soil improvement 193 $1,616 257 $3,421 450 $5,038 



Potting soils 14 118 6 221 20 338 



Packing flowers, shrubs, etc. __ 40 298 2 37 42 336 



Seed inoculant ___ 3 206 2 206 



Mushroom beds 3 29 C) (") 3 29 



Earthworm culture 1 9 C) 2 1 11 



Mixed fertilizers 6 27 .._ 6 27 



Total = 258 2^098 268 3,888 526 5,986 



^ Less than V2 unit. 



■ Data may not add to totals shown because of independent rounding. 



Although the average value of imported peat is 

 more than three times that of domestically pro- 

 duced packaged peat, the two are not comparable 

 because they are assigned at different marketing 

 levels. Also, imported peat has different physical 

 properties and is usually sold by volume rather than 

 by weight. Each 100 pounds of typical air-dried im- 

 ported peat measures approximately 12 bushels, 

 whereas the same quantity of a typical domestic 

 peat measures 3 or 4 bushels. Only a few U.S. peat 

 operators produce peat with properties similar to 

 those of the imported type. 



The quantity of peat imported into the United 

 States in 1970 decreased 6 percent from that im- 

 ported in 1969, mainly because of decreased ship- 

 ments from Canada. European shipments to the 

 United States decreased 9 percent, mainly because 

 of the smaller quantities shipped from Ireland and 

 Poland. Shipments from West Germany supplied 

 almost three-fourths of the peat imported from 

 Europe. 



PEAT DEPOSITS 



Soper and Osbon (1922) recognized three general 

 types of peat deposits, according to topography. 

 These include the filled basin, in which peat accu- 

 mulates in marshes, ponds, and lakes; the built-up 



deposit and its corollary, the climbing bog, in which 

 peat forms on flat or gently sloping moist areas not 

 covered with water; and the composite area con- 

 sisting of built-up peat underlain by peat of the 

 filled-basin type. 



The filled-basin type is predominant. Beginning 

 at the center of basins filled with water and pro- 

 ceeding shoreward, the usual sequence of vegetation 

 is algae, pondweeds, water lilies, bullrushes, and 

 amphibious sedges. Sphagnum and heath shrubs 

 sometimes grow on the marginal zones and are 

 abundant on the quaking bogs of the Northern 

 States. Adjoining zones of vegetation usually over- 

 lap, and some zones may be absent. Unless the 

 water is shallow enough to permit plants to take 

 root, fine-grained algal peat is normally at the bot- 

 tom of filled-basin deposits and is overlain by strata 

 of reed, sedge, and grass peat. Fire, drought, and 

 drainage, however, may prevent formation of suc- 

 cessive growth and decay of plant associations, and 

 changes in the surface water from alkaline to acid 

 may also affect composition of flora. 



Salt-marsh peat fills basins in much the same 

 manner as fresh-water peat but differs from it 

 somewhat in character. Because few seed plants 

 tolerate salt water, the number of plant varieties in 

 salt marshes is small. Salt-marsh peat is composed 



