scholarly journals Gravimetric survey and modeling of the basement morphology in the sedimentary thickness characterization, NE portion of Paraná Sedimentary Basin - Brazil

2017 ◽  
Vol 47 (2) ◽  
pp. 249-260 ◽  
Author(s):  
Maximilian Fries ◽  
Walter Malagutti Filho ◽  
João Carlos Dourado ◽  
Mariana Aparecida Fernandes
Keyword(s):  
Sedimentary Basin ◽  
3D Visualization ◽  
Sedimentary Rocks ◽  
Gravity Anomalies ◽  
Forward Modeling ◽  
Surrounding Area ◽  
Gravimetric Survey ◽  
Paraná Sedimentary Basin ◽  
Structural High ◽  
Sedimentary Layer

ABSTRACT: The northeast portion of the Paraná Sedimentary Basin is distinguished by structural highs as the known Pitanga Dome, an uplifted structure identified in the last century. It represents a geological and evolutionary evidence of the Paraná Sedimentary Basin and has undergone inspired studies and intense exploration surveys. This study consists of a gravimetric survey in the Pitanga Dome area, State of São Paulo, Brazil. The Bouguer gravity anomalies have been identified and related to the structural high, sedimentary thickness, and the basement morphology. Processing and enhancement techniques were used for forward modeling based on previous studies. The three models from profiles sectioning the dome have a sedimentary thickness varying from 200 to 1.250 meters. The adopted methodology has provided important results determining that the Pitanga Dome can be understood through rational 3D visualization. The area can be interpreted as an undulating basement with thinning of sedimentary rocks related to deep features (structures) in the crust/mantle limit (Moho uplift). This characteristic is confirmed by the sedimentary layer thickening present throughout the surrounding area. The results also offer important insights and support for further studies concerning the genesis and evolution of this and other uplifted structures of the Paraná Sedimentary Basin.

Geoelectrical characterization using joint inversion of VES/TEM data: A case study in Paraná Sedimentary Basin, São Paulo State, Brazil

2014 ◽  
Vol 111 ◽  
pp. 33-46 ◽  
Author(s):  
Cassiano Antonio Bortolozo ◽  
Marco Antonio Couto ◽  
Jorge Luís Porsani ◽  
Emerson Rodrigo Almeida ◽  
Fernando Acácio Monteiro dos Santos
Keyword(s):  
Sedimentary Basin ◽  
Joint Inversion ◽  
Sao Paulo ◽  
São Paulo ◽  
Paulo State ◽  
São Paulo State ◽  
Paraná Sedimentary Basin

scholarly journals Basin Depth Mapping Beneath Wellington City Based on Residual Gravity Anomalies

2021 ◽  
Author(s):  
◽  
Alistair Stronach
Keyword(s):  
Gravity Anomaly ◽  
Sedimentary Basin ◽  
Gravity Data ◽  
Three Dimensional ◽  
Maximum Amplitude ◽  
Central Business District ◽  
Gravity Anomalies ◽  
Depth Map ◽  
Capital City ◽  
Detailed Knowledge

<p><b>New Zealand’s capital city of Wellington lies in an area of high seismic risk, which is further increased by the sedimentary basin beneath the Central Business District (CBD). Ground motion data and damage patterns from the 2013 Cook Strait and 2016 Kaikōura earthquakes indicate that two- and three-dimensional amplification effects due to the Wellington sedimentary basin may be significant. These effects are not currently accounted for in the New Zealand Building Code. In order for this to be done, three-dimensional simulations of earthquake shaking need to be undertaken, which requires detailed knowledge of basin geometry. This is currently lacking, primarily because of a dearth of deep boreholes in the CBD area, particularly in Thorndon and Pipitea where sediment depths are estimated to be greatest.</b></p> <p>A new basin depth map for the Wellington CBD has been created by conducting a gravity survey using a modern Scintrex CG-6 gravity meter. Across the study area, 519 new high precision gravity measurements were made and a residual anomaly map created, showing a maximum amplitude anomaly of -6.2 mGal with uncertainties better than ±0.1 mGal. Thirteen two-dimensional geological profiles were modelled to fit the anomalies, then combined with existing borehole constraints to construct the basin depth map. </p> <p>Results indicate on average greater depths than in existing models, particularly in Pipitea where depths are interpreted to be as great as 450 m, a difference of 250 m. Within 1 km of shore depths are interpreted to increase further, to 600 m. The recently discovered basin bounding Aotea Fault is resolved in the gravity data, where the basement is offset by up to 13 m, gravity anomaly gradients up to 8 mGal/km are observed, and possible multiple fault strands identified. A secondary strand of the Wellington Fault is also identified in the north of Pipitea, where gravity anomaly gradients up to 18 mGal/km are observed.</p>

Contrasting fold styles in a volcano-sedimentary succession

1996 ◽  
Vol 33 (8) ◽  
pp. 1193-1200
Author(s):  
Pierre A. Cousineau ◽  
Robert Marquis
Keyword(s):  
Sedimentary Basin ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Structural Models ◽  
Sedimentary Basins ◽  
Basaltic Rocks ◽  
Field Evidence ◽  
Sedimentary Succession

Structural analyses of folded volcano-sedimentary basins rely heavily on the identification and use of way-up structures. These structures are more numerous and widespread in sedimentary rocks than in volcanic rocks. Structural models for such basins can therefore be biased by this fact. The Caldwell Group of the Quebec Appalachians is a folded volcano-sedimentary basin bounded bay major faults. It contains locally abundant basalt-rich bands. Near Lac-Etchemin, way-up in basalt flows is determined by pillow shelves that reflect paleohorizontal planes. The strike and dip of these shelf structures were measured and plotted on stereographic projections. Field evidence and the interpretation of stereographic projections indicate that the basalt-rich bands form open folds that plunge gently to the southwest. However, sandstone-rich bands form tight folds with undulating hinge lines (sheath-like). During initial folding, the basalt formed competent bands with limited aerial extent that were fractured by synthetic and antithetic faults rather than folded. The basalt slivers maintained a near-horizontal attitude while adjacent sedimentary rocks were folded and faulted. Further shortening tightened folds in the sediment-rich bands while producing open folds in slivers of basaltic rocks.

scholarly journals The petrogenesis of tholeiitic diabases in eastern Parnaíba Basin: evidence for geochemical heterogeneities in the subcontinental lithospheric mantle in NE Brazil

2017 ◽  
Vol 47 (1) ◽  
pp. 109-126 ◽  
Author(s):  
Adriano Guilherme da Silva ◽  
Cícera Neysi de Almeida ◽  
Sérgio de Castro Valente ◽  
Leonardo Fonseca Borghi de Almeida
Keyword(s):  
Trace Element ◽  
Fractional Crystallization ◽  
Lithospheric Mantle ◽  
Sedimentary Basin ◽  
Sedimentary Rocks ◽  
Geochemical Modelling ◽  
Subcontinental Lithospheric Mantle ◽  
Tectonic Events ◽  
Tholeiitic Magmatism ◽  
Parnaíba Basin

ABSTRACT: The sedimentary rocks within the Paleozoic Parnaiba basin in NE Brazil were intruded by voluminous tholeiitic diabase sills and covered by coeval basaltic flows. This paper presents lithogeochemical data of borehole samples obtained from wells located in the eastern portion of the Parnaiba basin. The diabases are subalkaline tholeiitc rocks comprising three high-TiO2 and three low-TiO2 suites that are unrelated by differentiation processes. Fractional crystallization of olivine and augite was the predominantly evolutionary processes within individual high- and low-TiO2 suites as depicted by trace element geochemical modelling, exception being made for one low-TiO2 suite that evolved by AFC. Parental compositions for both low- and high-TiO2 suites are related with variably enriched, spinel harzburgitic sources likely to represent the heterogeneous subcontinental lithospheric mantle underneath the sedimentary basin. The geochemical provinciality of the Parnaiba tholeiitic magmatism seems unrelated with the Transbrasiliano Lineament but may be due to lithospheric mantle amalgamation and remobilization occurred during previous tectonic events.

scholarly journals Gravity anomalies, sub-surface structure and oil and gas migration in the Mamfe, Cameroon-Nigeria, sedimentary basin

2007 ◽  
Vol 46 (2) ◽  
pp. 129-139
Author(s):  
Théophile Ndougsa-Mbarga ◽  
Eliezer Manguelle-Dicoum ◽  
José-Oscar Campos-Enriquez
Keyword(s):  
Surface Structure ◽  
Oil And Gas ◽  
Sedimentary Basin ◽  
Gravity Anomalies ◽  
Gas Migration

Este estudio reporta resultados preliminares de una interpretación formal de datos existentes de un área hasta hoy desprovista de estudios geofísicos, la cuenca de Mamfe (Camerún nor-occidental/ Nigeria sur-oriental). La importancia de esta cuenca se comprende por el hecho de que está genéticamente relacionada con la depresión de Benue productora de hidrocarburos. Los mapas de anomalías gravimétricas regional y residual proporcionaron información sobre la estructura de la cuenca. Las componentes gravimétricas regional y residual se obtuvieron ajustando con el método de mínimos cuadrados una superfi cie polinomial de tercer grado a la anomalía de Bouguer. La anomalía residual de tercer orden revela la presencia de dos bajos gravimétricos orientados NE-SW. La anomalía occidental cubre las poblaciones de Ekok y Agbokem, y la oriental comprende a Mukonyong, Mamfe y Bachuo Akagbe. Dos cinturones orientados aproximadamente E-W de anomalías gravimétricas positivas limitan por el norte y el sur respectivamente a las anomalías antes descritas. En general los bajos gravimétricos son debidos al relleno sedimentario de la cuenca, en tanto que las anomalías residuales positivas son el producto de afloramientos del complejo basamental. El patrón de las anomalías nos permite inferir las características generales de la cuenca. Ella comprende dos sub-cuencas separadas por un alto estructural. La cuenca occidental es la más profunda y compuesta. Comprende dos sub-cuencas separadas por un alto estructural menor, posiblemente relacionado con la continuación hacia la cuenca del complejo cristalino. En general, estas sub-cuencas tienden a ser más someras hacia el oriente indicando que la cuenca evolucionó de oeste a este. Las direcciones de migración de hidrocarburos probablemente generados en el depocentro han sido indicadas. La acumulación de hidrocarburos a lo largo de estas direcciones es posible, pero estudios sísmicos y gravimétricos más detallados deben ser emprendidos para buscar trampas estructurales o estratigráficas. Este estudio puede servir de base a un programa integral de exploración petrolera.

scholarly journals Quantitative Interpretation of Gravity Anomalies in the Kribi-Campo Sedimentary Basin (South Cameroon) Based on Spectral Analysis and 2.5D Modelling: Structural Implications

2020 ◽  
Vol 09 (03) ◽  
pp. 240-254
Author(s):  
Kue Petou Rokis Malquaire ◽  
Owona Angue Marie Louise Clotilde ◽  
Njingti Nfor ◽  
Eloundou Essama Lionel ◽  
Mioumnde Arthur Paterne ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Sedimentary Basin ◽  
Gravity Anomalies ◽  
Quantitative Interpretation

scholarly journals Age moving of layers: facts and geological consequences (to the 150th anniversary of N.A. Golovkinsky’s fundamental work)

Georesursy ◽  
2018 ◽  
Vol 20 (4) ◽  
pp. 278-289
Author(s):  
Svetlana O. Zorina ◽  
Valery P. Alekseev ◽  
Edward O. Amon ◽  
Ksenia A. Khasanova
Keyword(s):  
Sequence Stratigraphy ◽  
Cognitive Process ◽  
Sedimentary Basin ◽  
Methodological Approach ◽  
Sedimentary Rocks ◽  
150Th Anniversary ◽  
Nonlinear Science ◽  
The Relationship

The fundamental facial law, determining the relationship between facies of sedimentary rocks in the sedimentary basin in lateral and vertical extensions, was formulated by the Russian geologist N.A. Golovkinsky a century and a half ago. Theoretical statements and views proposed by Golovkinsky have not lost their importance and relevance nowadays. In the article considered an important aspect of diachroneity (heterochroneity) of layer associations and their litho- and biostratigraphic boundaries. The methodological approach of measuring its degree (the window of age moving) is proposed. Golovkinskiy’s conceptions are developing fruitfully within the framework of Seismostratigraphy and Sequence Stratigraphy, and their main content remains in demand in the light of new realities of cognitive process (nonlinear science, NBICS convergence, endovision).

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