NOME: EVALDO DE ANDRADE COELHO GUEIROS
ORIENTADOR: CARLOS EDUARDO DE
MORAES FERNANDES
TÍTULO: "GEOLOGIA DE UM PALEO 'CANYON' SUBMARINO DA BACIA DO
ESPÍRITO SANTO"
ABSTRACT: The REGÊNCIA CANYON is a submarine feature, of Late
Cretaceous age, located in the southern portion of the Rio Doce mouth, in
Espírito Santo Basin. According to seismic reflection data and four dry holes
drilled down to the cristaline basement, it was possible to set up the probable
geologic history for the canyon. Sand turbidites were mapped and these show very
good possibilities for hydrocarbon prospecting.
NOME: ROGÉRIO CARVALHO DE GODOY
ORIENTADOR: WENDELIN FRANZ
LOTZE
TÍTULO: "VARIAÇÃO SECULAR DA INTENSIDADE DO CAMPO GEOMAGNÉTICO NO
BRASIL"
BANCA EXAMINADORA: CARLOS EDUARDO DE MORAES FERNANDES, ANTONIO
SALDANHA DE SOUZA NEVES
JOSÉ DE SÁ BORGES FILHO DATA DA DEFESA: 29 DE
DEZEMBRO
NO DO PROCESSO: 36.237/80
ABSTRACT: A survey of available data,
useful for computations of geomagnetic models in Brazil was done. Site
descriptions as well as well as observed values in repeat stations and annuel
mean values of geomagnetic observatories were revised, corrected, coded and
organized in digital files. Two models of the total intensity of geomagnetic
field and four models of its secular variation were computed using the data
files. The models are evaluted according to geomagnetic observatory data and
compared with other models. Conclusions on changes in field work methodology and
about future work flow are derived.
NOME: JANDYR DE MENEZES TRAVASSOS
ORIENTADOR: AUGUSTO CESAR BITTENCOURT
PIRES
TÍTULO: "DISTORÇÃO DO CAMPO GAMA PRIMÁRIO NA CAMADA ATMOSFÉRICA
SUPERFICIAL CAUSADA PELA BIOMASSA AÉREA DE UMA FLORESTA"
BANCA EXAMINADORA:
WENDELIN FRANZ LOTZE, ANTONIO SALDANHA DE SOUZA NEVES, JOSÉ DE SÁ BORGES
FILHO
DATA DA DEFESA: 25 DE NOVEMBRO
NO DO PROCESSO:
39.772/81
ABSTRACT: The screening effect of a forest cover is determined for
local and extended gamma-field sources in the soil. We choose a tropical rain
forest on the "terra firme"near Manaus with a biomass of 10g/cm2 . The screening
is estimated assuming a layered structure of the aerial phytomass. This has
shown that can be considered independent of survey altitude in the range 100 -
200m, with less tha 10% errors. The anisotropy on trunks of trees is estimated
using Monte Carlo method. It has shown that anisotropy can kead toerrors in the
estimated screening effect reaching 20%. Radioactive properties of the stand
were analysed. This has shown to reach 10% of the radiation from gamma-field
sources in the soil.
NOME: HUGO RICHARD BERTETE AGUIRRE
ORIENTADOR: WENDELIN FRANZ
LOTZE
TÍTULO: "LEVANTAMENTO GRAVIMÉTRICO, MODELAMENTO BI-DIMENSIONAL
AUTOMÁTICO E INTERPRETAÇÃO NA REGIÃO OCIDENTAL DA BAIXADA DE JACAREPAGUÁ -
RJ"
ABSTRACT: The aim of the present investigations enclose three principal
aspect: 1) gravimetry survey, 2) methodology development of automatic
two-dimensional modellig, and 3) interpretation of gravity anomalies. The chosen
area for the application was the occidental region of the "Baixada de
Jacarepaguá-RJ". Based on geological and geomorphological data of the area, and
on the gravity interpretations results was possible to detect: a) maximum depth
of the sediments, which is aproximately of 150 m; b) regions were the basament
is practicaly emerging; c) possible secondary paleo-canals with and average
depth of 70-80 m. The area presents gravity anomalies bigger than the one
initialy expected. The maximum amplitude verified was 2.7 mgal. Computers
programs were developeded in the present thesis for the gravimetry reductions,
prefencialy to the automatic two-dimensional gravity modelling. The original
algorithm (Qureshi, 1971) was modified in this work to improve the convergence
and reability of the results.
NOME: PAULA LUCIA FERRUCIO DA ROCHA
ORIENTADOR: CARLOS EDUARDO DE MORAES FERNANDES
TÍTULO: "MAPA PRELIMINAR DE CONTORNO DO TOPO DO EMBASAMENTO CRISTALINO, COM
BASE EM PROSPECÇÃO GRAVIMÉTRICA, DA BAIXADA DE JACAREPAGUÁ - RJ - BRASIL"
ABSTRACT: In this work, we present the results of a geophysical survey, by gravimetric
measurements, in a 6 km by 17 km area, at Baixada de Jacarepaguá (Rio de Janeiro
- Brazil) aiming to determine depths for the basement complex. Measurements
were performed at 66 sites with an Autograv CG-3 Scintrex gravimeter, owned
by UFRJ, the distance between nearest sites being typically 1 km. The results
of the survey allowed us to construct a contour map for the crystalline basement,
in a 1:25.000, scale. Detailed computations, based on geological, geomorphological
and gravimetric data revealed the existence of an irregular paleorelief, corresponding
to the original subsurface which then formed the bottom of part of a sedimentary
basin (Pliocene, according to Roncarati and Neves, 1976) in which sedimentation
was beginning. The possible existence of faults and intruding bodies in the
basement is also discussed. The contour map is considered to be preliminary
due to the fact that our interpretation lacks depth control to basement by boring
and also due to the fact that the station density for the area is not sufficient
to completely cover the rock interface irregularities.