Dissertação
Feições de carste sobre a formação Serra Geral no município de São Martinho da Serra - RS
Fecha
2012-03-27Registro en:
GUARESCHI, Vinícius Duarte. KARST FEATURES ON SERRA GERAL FORMATION IN SÃO
MARTINHO DA SERRA - RS. 2012. 98 f. Dissertação (Mestrado em Geociências) - Universidade Federal de Santa Maria, Santa Maria, 2012.
Autor
Guareschi, Vinícius Duarte
Institución
Resumen
Karst features are more common in relief formed by carbonate rocks, but can occur in
silica-rich rocks such as volcanic acid, a fact not yet explored. Thus, this Master's thesis
aims to understand the mechanisms responsible for the development of these landforms
associated volcanic rocks through the identification and mapping of karst features,
analyzing its relationship with the slope, hypsometry, lithology and morpho-structural
lineaments. Furthermore, we tried to relate the distribution of features with use and land
cover and check the fragility of the Serra Geral Aquifer. The study area comprises the
city of São Martinho da Serra - RS, basic and acidic volcanic rocks of the Serra Geral
formation. For this, the karst features were identified and mapped using satellite
imagery, and morpho-structural lineaments were extracted from SRTM. We generated
various cartographic products, which combined with field observations, allowed to
classify the karst features that occur in the study area into three types of depressions
that correspond to different stages of morphological evolution: a) Depression Surface
Planed Top b) Headwater drainages suspended; c) Depression in the Valley bottom. It
was found that karst features are controlled by the morpho-structural lineaments, and
tend to develop in portions of volcanic flows that are more easily affected by weathering.
It was observed that the depressions in the surface Planed Top occur more frequently in
the municipality where the land use is predominantly agricultural, denotes the fact that
risk of contamination of the aquifer Serra Geral, since its recharge also occurs through
these features.