The studies on the formation of Terra Rossa soils in the karst of the Peninsula of Yucatan can be grouped into three types: (a) regional studies with intensive fieldwork, description of soil profiles and relief; (b) site studies with intensive fieldwork but restricted spatially; and (c) case studies (point or small areas) including geochemical and micromorphological analyses.

The first two study types adopted the hypothesis of residual origin through limestone dissolution, while the third type adopted the hypothesis of the contribution of allochthonous materials. In fact, only in two cases allochthonous materials were detected in the soils. Other studies argue that Leptosols are essentially products of soil degradation or result from a mixture of allochthonous and autochthonous materials.

Better understanding of soil formation requires knowing the spatial distribution of the soils that allows constructing models of soil sequences in multiple directions along various types of gradients. This approach was applied to comprehend the soil formation from the soil distribution in the tropical karst areas of the Peninsula of Yucatan, Mexico.

Satellite images were used to identify flooded areas. After conducting numerous field verifications and analyzes, landforms and soils were combined to make a soilscape map. Based on field observations and the soilscape map, soil development was analyzed on soil sequences.

Four geomorphic environments were identified, karstic plains and hills with Leptosols, Cambisols, Luvisols, Vertisols; coastal plains with Arenosols, Regosols, Solonchacks, Histosols; fluvio-paludal plains with Gleysols, Histosols, Leptosols and Solonchacks; and tectono-karstic plains and hills with Leptosols, Cambisols, Luvisols, Vertisols.

Figure 5

Relevant soil forming factors in the Peninsula of Yucatan include time of emersion of the limestone platforms, climate, rock type, and macro- and micro-relief. Other factors such as groundwater level, fractures, also have an influence on soil formation. Karst development can be considered as a complex soil and relief forming factor. Terra Rossa soils as Leptosols, Cambisols, Luvisols, Nitisols and Vertisols in the Peninsula of Yucatan may be polygenic. In some cases, the theory of residual origin fits better the data than the theory of allochthonous origin; in other cases, it is the other way around.

Figure 10

Bautista F., G. Palacio, P. Quintana and A. J. Zinck. 2011. Spatial distribution and development of soils in tropical karst areas from the Peninsula of Yucatán, Mexico. Geomorphology. 135: 308–321.

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