Produção Nacional
Airborne geophysical and tectonics of the Ceará central domain, eastern region of the Santa Quitéria magmatic ARC, Borborema Province, NE Brazil
2008; Brazilian Society of Geophysics; Volume: 26; Issue: 4 Linguagem: Inglês
10.1590/s0102-261x2008000400012
ISSN1809-4511
AutoresWagner da Silva Amaral, Ticiano José Saraiva dos Santos,
Tópico(s)Geophysical and Geoelectrical Methods
ResumoThe airborne geophysical data gamma-spectrometric and magnetic from Itatira Project (1977) was carried out, in the central region of the State of the Ceará, Brazil. Their processing produced products useful to indirectly identify regional geologic features. The verification and applicability of this approach was tested in a pilot-area whose limits are within the Umirim and Canindé topographic sheets, at 1:100,000 scale. The integration between the airborne geophysical and the geologic field data supported to the geologic mapping at the same cited scale. Two main units were recognized: the Santa Quitéria magmatic arc and the supracrustal sequences that surround the arc. The rocks fram Santa Quitéria magmatic arc are characterized by high counting on the K-channel in its almost entire region and intermediate and low counting of eTh and eU. Generally, the supracrustal sequences are characterized by high values on the eU-and-eTh-channels and low on K-channel. The subunit metaultramafics and, mafics granulites, are remarkable by the occurrence retrograde eclogites bands and mafic granulites as lenses within gneisses and migmatites. These subunits present strong negative anomalies, with low counting on the three K, eTh and eU channels. That area also has positive magnetic anomalies, and may reflect high values of magnetic susceptibility.
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