Relação solo-relevo-substrato geológico na planíce costeira de Bertioga (SP) / Soil-relief-geologic substract relationship on the coastal plain of Bertioga (SP)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Knowledge of the chronology, relief, geology and soils in sedimentary coastal environments is relevant for their interpretation, reconstitution and conservation. In Bertioga, São Paulo State Brazil, several sections of the Pleistocene and Holocene morphostratigraphic costal plain units are preserved in the landscape. This thesis seeks the perception of the relationships between soils, geomorphology, relief and the chronology of Bertiogas coastal sand deposits as well as to study Podzols developed on them. Soils and the different sedimentary environments where these soils develop were thus identified and characterized. Photointerpretation, field work, chemical, physical and chronological (luminescence and radiocarbon dating) analysis supported the identification, spatial delimitation as well as the development of genesis theories of soils over continental, fluvial and marine deposits. Previous data additionally allowed the evaluation of the influence of relief forms and water table depth on the evolutionary dynamics of soils and on their spatial distribution pattern. The main identified orders of soils included Podzols, Arenosols, Fluvisols, Histosols, Gleysols and Cambisols. The topographic, geomorphologic and geologic differences of the environments had conditioned the amount of water, the vegetation features and the organic matter content of the following geomorphologic units: (a) lagoonal terrace depressions, characterized by organo-pelitic-psammitic sediments under Histosols and Gleysols; (b) marine terraces formed by fine to very fine sand under Podzols with and without hardpans (ortstein); (c) fine sandy beach ridges with a dominance of Arenosols and, on a secondary level, Podzols without hardpans (ortstein) and placic horizons; (d) psammitic colluvial slope deposits with Cambisols; (e) fluvial plains with varied texture and with Gleysols and Fluvisols and (f) psammitic and pelitic tidal flats, where Histosols and Gleysols predominate. Besides these units, modern beaches and sections dominated by non-differentiated colluvial-alluvial continental deposits were also analyzed as individual geomorphological units. Topography of geomorphological units from marine origin indicates the chronological sequence of deposits, in addition to influencing the development of different of Podzols, the physical, chemical and morphological properties of which allowed the chronological differentiation of modern Quaternary deposits (Holocene). The mapped area of the Pleistocene marine terraces occurrence was found to be larger than the one indicated on cartographic documents published up to the moment. In the well-drained sections of remnant soils from high Pleistocene marine terraces, the influence of the relief forms on pedogenesis is shown through the formation of Arenosols originated from the destruction of spodic horizons, whereas Arenosols in Holocene marine terrace tends to evolve into Podzols.

ASSUNTO(S)

espodossolos - propriedades físico-químicas coastal plain geomorfologia pedologia restinga. geomorphology geologia restinga. podzols

ACESSO AO ARTIGO

Documentos Relacionados