| Autor: |
Mantovani, Marta S. M., Shukowsky, Wladimir, de Brito Neves, B. B., Rugenski, André |
| Předmět: |
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| Zdroj: |
Geophysical Prospecting; Sep2008, Vol. 56 Issue 5, p751-760, 10p, 4 Diagrams, 1 Chart, 3 Graphs, 1 Map |
| Abstrakt: |
A semi-detailed gravity survey was carried out over an area of 650 km2 localized in the Eo-Neoproterozoic coastal zone of Paraiba State where 548 new gravity stations were added to the existing database. Gravity measurements were made with a LaCoste and Romberg model G meter with a precision of 0.04 mGal. The altitude was determined by barometric levelling with a fixed base achieving a 1.2 m measure of uncertainty, corresponding to an overall accuracy of 0.24 mGal for the Bouguer anomaly. The residual Bouguer map for a 7th degree regional polynomial showed a circumscribed negative anomaly coincident with a localized aero-magnetic anomaly and with hydro-thermally altered outcrops, near the city of Itapororoca. The 3D gravity modelling, constrained by geologic mapping was interpreted as a low density, fractured and/or altered material with a most probable volume of approximately 23 km3, extending to about 8,500 m depth. This result is in accordance with a volcanic body associated with hydrothermal processes accompanied by surface mineralization evidence, which may be of interest to the mining industry. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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