9 documents found, page 1 of 1

Análise morfológica da estrutura circular de São Miguel do Tapuio, Piauí - Brasil

The São Miguel do Tapuio Circular Structure (SMTCS) is one of the largest recognized in the Phanerozoic sedimentary rocks of the Parnaiba Basin, in Piauí (PI), Brazil. Research works on the genesis of the SMTCS consider either an endogenetic origin or meteoritic impact formation. The present study is based on bibliographic survey, fi eldwork and laboratory analyses (remote sensing). The SMTCS superfi cial morph...

Diretrizes para aquisição e processamento de dados geofísicos magnetotelúricos:...

Since the 1950s, the magnetotellurics method (MT) has been widely used in mineral and oil prospecting (sedimentary basins), cratonic regions and recognitions of crustal-scale geological discontinuities. MT geophysical method consists of a passive technique that aims to investigate geoelectric characteristics of subsoil through the interaction between telluric currents and subsurface materials. The objective of ...

On the tectonics of the Neocomian Rio do Peixe Rift Basin, NE Brazil: Lessons f...

A geophysical perspective based on well-acquired gravity, magnetic, and radiometric data provides good insights into the basin architectural elements and tectonic evolution of the Rio do Peixe Basin (RPB), an Early Cretaceous intracontinental basin in the northeast Brazilian rift system, which developed during the opening of the South Atlantic. NW–SE-trending extensional forces acting over an intensively deform...

4-D ground penetrating radar monitoring of a hydrocarbon leakage site in Fortal...

A 4-D monitoring GPR survey was carried out in order to outline the light non-aqueous phase liquid (LNAPL) plume underground during a remediation process in the area of an impacted gas station in Fortaleza, NE Brazil. The complex GPR signature of the plume was well characterized. Low reflectivity zone corresponds to hydrocarbon vapor phase in the vadose zone. Enhanced reflections are associated with free and re...

Radiometric, magnetic, and gravity study of the Quixadá batholith, central Cear...

A geophysical survey was conducted in the central Ceará domain of the Borborema Province (NE Brazil). The aim of this investigation was to find geophysical evidence for the emplacement of the Quixadá batholith, which is a granitic body probably situated in the local extensional site in the oblique collisional regime of the Pan-African/Brasiliano collage. Remote sensing and airborne geophysical data provided inf...

A morfologia superficial da estrutura circular de São Miguel do Tapuio (Piauí-B...

The circular structure of São Miguel do Tapuio (ECSMT) is a striking geomorphological feature noted in the Mesopaleozoic sandstones of Parnaiba basin (Piaui-BR). In this work the morphological characterization of ECSMT surface was mainly provided using SRTM topographic data. Such characterization allowed us to outline a 20 Km diameter and define the following: the circular structural pattern distinguished in it...

Análise da recepção do sinal VLF da Estação NAA (24.0 Khz) EUA e sua utilização...

During the last decades, several authors have demonstrated the usefulness of VLF (Very Low Frequency) geophysical surveys as a fast and powerful tool on surveying geological structures (faults, fractures, diaclases, contacts, dikes, etc.). Other applications involve mineral prospecting, civil engineering, contaminants identification and especially groundwater prospecting. During this research, it was verified t...

Aplicação do método gravimétrico para estudo da geologia de subsuperfície na ár...

The gravimetríc methods are very important in subsurface geology surveys due to their diverse applicability, and have been used since hydrocarbons exploration until geological studies, such as in the investigations of large and médium scale structures. In order to enable the researchers team of the Laboratório de Geofísica de Prospecção e Sensoriamento Remoto (LGPSR), an acquisition of gravimetríc data was exec...

Interpretação das assinaturas geofísicas relacionadas a estrutura da Bacia de C...