Pedogenic horizons

Entisols. Mineral soils that have no distinct subsurface diagnostic horizons within 1 m of the soil surface. Entisols have little or no evidence of the development of pedogenic horizons. Most Entisols have no diagnostic horizons other than an ochric epipedon. Entisols are divided into five suborders Aquents, Arents, Psamments, Fluvents, and Orthents. 

Rowley DB, Garzione CN (2007) Stable isotope-based Paleoaltimetry. Annu Rev Earth Planet Sci 35 463-508 Royer D (1999) Depth to pedogenic carbonate horizon as a paleoprecipitation indicator Geology 27 1123-... 

Usually, each soil layer or horizon is given a pedogenic notation (e.g., A, B, C) indicating its position in the soil profile and drawing attention to... 

Horizons little affected by pedogenic processes. May include soft sedimentary material (C) or partially weathered bedrock (Cr)... 

Accumulation of calcium carbonate due to pedogenic processes Nearly continuously cemented horizons (by various pedogenic minerals) Accumulation of exchangeable sodium... 

Figure 2.8 Dynamic model for pedogenic calcrete development based on Alonso-Zarza et al. (1998). Existing calcrete horizons of profiles may be remobilised following some degree of exhumation (Elbersen, 1982) or by changes in rainfall.

The soil profile is the manifestation of the soilforming or pedogenic processes on the geological substratum or parent material (Fig. 7-1). The soil profile is an assemblage of horizons displayed by a vertical cut at the surface. Horizons are layer-like, more or less parallel to the surface, and differ from each other in morphology, composition, and consistency (Table 7-1). 

This table is part of Fig. 7-4. It shows the major proton donors and the major weathering reactions occurring in the different compartments (horizons) of a soil profile. It is assumed that the parent material consists of unconsolidated granite, materials are freely drained, and pedogenic impeding layers are absent. Also, no perched or fluctuating water is present. 

The subscript g is used to indicate a gleyed horizon resulting from the reduction of Fe +. Use of g with B indicates pedogenic changes in the horizon, and use of g with C suggests no pedogenic changes in the horizon. 

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