Banca de QUALIFICAÇÃO: PEDRO HENRIQUE MOURA DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : PEDRO HENRIQUE MOURA DA SILVA
DATA : 06/07/2018
HORA: 14:30
LOCAL: Auditório do LGGP I
TÍTULO:

STRUCTURAL CONDITIONING AND STRATIGRAPHICAL RELATIONSHIPS OF JURASSIC MAGMATISM IN THE CENTRAL-WEST PORTION OF PARNAÍBA BASIN

PALAVRAS-CHAVES:

Early Jurassic basic magmatism; Geological mapping; Mosquito Suite; Parnaíba Basin; Stratigraphic relations; Structural signature.

PÁGINAS: 45
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

The Early Jurassic basic magmatism of the Parnaíba Syneclisis, represented by the Mosquito Suite, is well studied from the petrological and even geochronological points of view. Its cartography in the Teresina and Araguaia 1:1,000,000 maps is available at the data files of the Geological Survey of Brazil (CPRM). Seismic surveys, wells (available at BDEP/ANP database), and field data allow to characterize an important sill complex of this unit, with lengths on the order of tens of kilometers. This magmatic suite is evaluated as influential in the formation of unconventional petroleum systems. The area of the present study is located in the center-western portion of the basin, which concentrates the largest expoure of volcanic and sub-volcanic rocks related to this event. Magmatic bodies display an expressive pattern of E-W to ENE trending lineaments, including elongated plateaus in this direction. This work deals with the structural and stratigraphic controls of the Mosquito Suite, which involved the preparation of a geocartographic base using the present available maps plus modifications based on field data (structures and chronostratigraphic relations), as well as results of orbital remote sensing imagery (optical and radar) interpretation, involving the application of enhancement techniques, producing shaded relief maps, digital elevation models and colorful compositions. In addition, subsurface information obtained from well profiles combined with regional geological sections and some more detailed profiles, were also used. Mapping of the geological contacts in previous maps was modified based on the spectral signatures identified for the lithostratigraphic units, as well as on topographic control and field data. The macrostructures were mapped from the interpretations of photolineaments, which were correlated with outcrop structures. The study also dealt the relations of the sedimentary units with the magmatic suite, based mainly on field observations and petrographic data. The area previously mapped as Mosquito Suite was restricted, with more emphasis placed in the areal extent of the Sambaíba Formation intruded by sills, these diagnosed by intrusive contacts (including sill jumps) and contact metamorphism. The magmatic (sub)outcropping bodies also include lava flows (or very shalow sills), as implied by the presence of sedimentary intercalations (intertrap sediments), which differ, lithologically and petrographically, from the siliciclastics of the Sambaíba Formation and the overlying Corda Formation. This unit presents an important erosional surface at its base, with pebbles of cherts and basic rocks. The cartography and mesoscopic characterization of faults, their kinematics and relations with the units mentioned above, allowed to identify three phases of brittle deformation that precede, succeed, or are contemporary and controls the emplacement of the magmatic bodies.

MEMBROS DA BANCA:
Externo ao Programa - 2490483 - ALEX FRANCISCO ANTUNES
Presidente - 1217847 - FERNANDO CESAR ALVES DA SILVA
Interno - 1149363 - VALERIA CENTURION CORDOBA