Genesis and Classification of Soils Containing Carbonate on the Apodi Plateau, Brazil
| Autor: | Rafael Cipriano-Silva, Marcos Gervasio Pereira, Edilene Pereira Ferreira, Lúcia Helena Cunha dos Anjos, Gustavo Souza Valladares, Antonio Carlos de Azevedo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Soil Science
Mineralogy Petrocalcic Horizon engineering.material Brazilian Soil Classification System 010502 geochemistry & geophysics 01 natural sciences chemistry.chemical_compound lcsh:Agriculture (General) 0105 earth and related environmental sciences Soil morphology Soil classification 04 agricultural and veterinary sciences lcsh:S1-972 Pedogenesis chemistry Soil water Illite 040103 agronomy & agriculture engineering 0401 agriculture forestry and fisheries Carbonate Agronomy and Crop Science Calcareous Geology Karst system soil mineralogy soil micromorphology |
| Zdroj: | Revista Brasileira de Ciência do Solo v.40 2016 Revista Brasileira de Ciência do Solo Sociedade Brasileira de Ciência do Solo (SBCS) instacron:SBCS Revista Brasileira de Ciência do Solo, Volume: 40, Article number: e0150036, Published: 31 MAY 2016 Revista Brasileira de Ciência do Solo, Vol 40, Iss 0 (2016) |
| Popis: | Information is scarce on the genesis and classification of soils derived from calcareous rocks in the Northeastern region of Brazil. This study describes the morphological, physical, chemical, mineralogical, and micromorphological properties of four soil profiles (P1-P4) located in the Apodi Plateau. A pedogenesis hypothesis and soil classification, according to the Brazilian System of Soil Classification (SiBCS), are proposed for these profiles. The interactions between parent material, surface topography and climate affected the pedogenesis processes and soil properties, although the calcareous nature of the parent material most affected the soil morphology and chemical properties. The sand fraction contained mainly quartz and calcite, and a smaller amount of mica. Smectite and interstratified illite-smectite occurred in the clay fraction of profile P1 and in some horizons of P2 (Ccmќ and Ccrќ) and P3 (2Ccrќ). Kaolinite predominated in profiles P2, P3, and P4; where as illite and vermiculite were present in the Bicќ, Bcќ, Bcmќ horizons of P2, in Bt2c of P3, and in C of P4. The mineralogy showed illite, hematite, and goethite, and anatase in a number of horizons. Micromorphological analysis of P2 indicated a strong cementation of Bcmќ and Ccmќ by calcium carbonate, and other properties indicate the formation of a petrocalcic horizon, but this horizon lacked lateral continuity in the profile. Therefore, the parapetrocalcic term is proposed for classifying P2 in the fourth level of the SiBCS. The 3Biќ-P1 horizon exhibited calcite coating and iron coating or quasi-coating, indicating distinct pedogenesis processes occurring under different environmental conditions. Likewise, the occurrence of petroplinthite in P2 indicates that climatic conditions during its formation differed from present conditions, and both situations are interpreted as evidence that the soils were formed by polygenetic processes. In the SiBCS classification, the soils are classified as Cambissolo Háplico Carbonático vertissólico (P1), Cambissolo Háplico Carbonático concrecionário (P2), Luvissolo Crômico Pálico petroplíntico (P3), and Neossolo Litólico Carbonatico típico (P4); and a new class (parapetrocálcico concrecionário) is proposed for P2 in the fourth level. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|