IMPORTANT TYPES OF PEAT MATERIAL. 23 



UOI'HLKKITIC lYPK. 



" Dopplerit." 



Blackish, structureless, compact, somewhat plastic, and homogene- 

 ous debris of mixed origin. An organic complex (organic lime salt; 

 calcic humate), which is partly an end product of disintegi'ation 

 combined with lime and which probably results from a reaction be- 

 tween disintegrating, oozelike and very finely divided fragments of 

 a variety of herbaceous plants, soft, woody tissue, etc., in the pres- 

 ence of ground water from sedimentary limestones or calcareous drift. 

 The type has been found also as a surface layer on peat lands which 

 appear to have been subject to prolonged shallow inundation of 

 water carrying organic debris in suspension. The material is hard 

 when dry, resembling bitumen or lignite, occasionally of a shiny 

 vitreous appearance resembling anthracite;. it weathers into angular, 

 ii'regular-shaped fragments which gradually break down into a fine 

 black dust in overdrained fields. The chemical data in Table I are 

 representative for this type of peat material. 



A similar organic complex but mainly ferruginous in character is 

 found in some peat deposits (ferric humate) which appears to arise 

 in a like manner through the action of chalybeate ground waters. 



THE MARSH GROUP OF PEAT MATERIALS. 



Types of peat material (autochthonous) from meadow stages of a 

 vegetation series in treeless wet places with a water table near or 

 slightly above or below the surface, or partially submerged during 

 part of the year. 



The peat materials are essentially fibrous and somewhat felty or 

 matted, formed in the main from roots and rootlets of plants (radi- 

 cellate peat). Macerated plant remains, seeds, fragments of various 

 tissues, and woody components from shrubs are present in moderate 

 or large quantities according to the degree of inundation of the area. 



The types are derived from various vegetation units, such as 

 sedges, reeds, cat-tails, rushes, and grasses. If water-formed layers 

 of peat material and their wind-blown or otherwise transported drift 

 components described above are absent in the profile structure of a 

 peat deposit, it points to the fact that the conditions for the growth 

 of plants and the accumulation of their remains are entirely different 

 from those already discussed. The noteworthy characteristic is the 

 presence of roots which traversed the old soil or the shallow bottom 

 of mud. The network of roots, rootlets, and rhizomes with its en- 

 tangled matted mass of aerial plant remains also shows that the area 

 had an initial water table near the surface or above it during only a 

 part of the year. To the degree in which the plants form a closed 



