Hudson Bay, Bouguer anomaly map

10.4095/8346 ◽  
1978 ◽  
Author(s):  
Keyword(s):  
Bouguer Anomaly ◽  
Hudson Bay ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

STRUCTURAL IMPLICATIONS OF THE GRAVITY FIELD IN HUDSON BAY AND VICINITY

1967 ◽  
Vol 4 (5) ◽  
pp. 977-993 ◽  
Author(s):  
M. J. S. Innes ◽  
A. K. Goodacre ◽  
J. R. Weber ◽  
R. K. McConnell
Keyword(s):  
Gravity Field ◽  
Volcanic Rocks ◽  
Bouguer Anomaly ◽  
Major Change ◽  
Hudson Bay ◽  
Important Conclusion ◽  
Basement Rocks ◽  
Anomaly Map ◽  
Bouguer Anomaly Map ◽  
Basic Volcanic

The results of underwater gravity measurements of a reconnaissance nature in Hudson Bay and of regional gravity surveys over adjoining regions of the Canadian Shield and Hudson Bay Lowlands are presented in the form of a Bouguer anomaly map. The general anomaly pattern is discussed and an interpretation is presented. Analysis of anomaly profiles crossing Hudson Bay using seismic data for control, shows (1) that Paleozoic and recent sediments have little overall effect on the gravity field, and (2) that variations in depth to the crust-mantle boundary have little or no correspondence with variations in the gravity field. It is believed that the gravity variations are largely due to systematic density differences in the Precambrian basement rocks. An important conclusion is that the more positive gravity field over the northern part of Hudson Bay marks a major change in structure and that the Churchill crustal block does not extend uninterruptedly eastward; it is suggested that the positive anomalies reflect high-density metamorphic gneiss or basic volcanic rocks underlying the sedimentary veneer. Evidence is presented which strengthens the hypothesis that the Kapuskasing gravity anomaly and its northern and southern extensions mark an ancient zone of crustal rifting of continental proportion.

Tectonic insight and 3-D modelling of the Lusi (Java, Indonesia) mud edifice through gravity analyses

2021 ◽  
Vol 225 (2) ◽  
pp. 984-997
Author(s):  
Álvaro Osorio Riffo ◽  
Guillaume Mauri ◽  
Adriano Mazzini ◽  
Stephen A Miller
Keyword(s):  
Risk Mitigation ◽  
Bouguer Anomaly ◽  
Geological Model ◽  
Resource Exploitation ◽  
Subsurface Structures ◽  
Central Java ◽  
Geostatistical Interpolation ◽  
Gravity Response ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

SUMMARY Lusi is a sediment-hosted hydrothermal system located near Sidoarjo in Central Java, Indonesia, and has erupted continuously since May 2006. This mud eruption extends over a surface of ∼7 km2, and is framed by high containment dams. The present study investigates the geometry of the subsurface structures using a detailed gravimetric model to visualize in 3-D the Lusi system and surrounding lithologies. The obtained residual Bouguer anomaly map, simulated through geostatistical interpolation methods, supports the results of previous deformation studies. The negative gravity anomaly zones identified at Lusi are interpreted as fractured areas through which fluids can ascend towards the surface. A 3-D detailed geological model of the area was constructed with Geomodeller™ to highlight the main features. This model relies on the structures’ density contrasts, the interpreted residual Bouguer anomaly map, and geological data from previous authors. 3-D algorithms were used to calculate the gravity response of the model and validate it by inverse methods. The final output is a gravity constrained 3-D geological model of the Lusi mud edifice. These results provide essential details on the Lusi subsurface and may be useful for possible future geothermal resource exploitation and for the risk mitigation plans related to the maintenance of the man-made framing embankment.

scholarly journals Geophysical perspective on the structural interference zone along the Neoproterozoic Brasília and Ribeira fold belts in West Gondwana

2017 ◽  
Vol 47 (1) ◽  
pp. 3-19
Author(s):  
João Gabriel Motta ◽  
Norberto Morales ◽  
Walter Malagutti Filho
Keyword(s):  
Bouguer Anomaly ◽  
Shear Zones ◽  
Magnetic Data ◽  
Gravity Modeling ◽  
West Gondwana ◽  
Fold And Thrust Belt ◽  
Fold Belts ◽  
Thrust Sheets ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

ABSTRACT: The Brasília and Ribeira fold belts have been established in south-southwestern São Francisco Craton during the Brasiliano-Pan African orogeny (0.9-0.5 Ga - Tonian to Cambrian), and played an important role in West Gondwana continent assembly. The region is given by a complex regional fold and thrust belt superposed by shearing during the orogeny late times, with superposing stress fields forming a structural interference zone. These thrust sheets encompasses assemblies from lower- to upper-crust from different major tectonic blocks (Paranapanema, São Francisco), and newly created metamorphic rocks. Re-evaluation of ground gravity datasets in a geologically constrained approach including seismology (CRUST1 model) and magnetic data (EMAG2 model) unveiled details on the deep- crust settings, and the overall geometry of the structural interference zone. The Simple Bouguer Anomaly map shows heterogeneous density distribution in the area, highlighting the presence of high-density, high metamorphic grade rocks along the Alterosa suture zone in the Socorro-Guaxupé Nappe, lying amid a series of metasedimentary thrust scales in a regional nappe system with important verticalization along regional shear zones. Forward gravity modeling favors interpretations of structural interference up North into Guaxupé Nappe. Comparison to geotectonic models shows similarities with modern accretionary belts, renewing the discussion.

scholarly journals Geometrical Characterisation of the Mamfe Basin, Cameroon, from the Earth, Gravitational Model (EGM 2008)

2018 ◽  
Vol 7 (1) ◽  
pp. 94
Author(s):  
Anatole Eugene Djieto Lordon ◽  
Mbohlieu YOSSA ◽  
Christopher M Agyingi ◽  
Yves Shandini ◽  
Thierry Stephane Kuisseu
Keyword(s):  
Average Length ◽  
Gravity Data ◽  
Bouguer Anomaly ◽  
Igneous Rocks ◽  
Average Depth ◽  
The Earth ◽  
Gravitational Model ◽  
Petroleum Generation ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

Gravimetric studies using the ETOPO1-corrected high resolution satellite-based EGM2008 gravity data was used to define the surface extent, depth to basement and shape of the Mamfe basin. The Bouguer anomaly map was produced in Surfer 11.0. The Fast Fourier Transformed data was analyzed by spectral analysis to remove the effect of the regional bodies in the study area. The residual anomaly map obtained was compared with the known geology of the study area, and this showed that the gravity highs correspond to the metamorphic and igneous rocks while the gravity lows match with Cretaceous sediments. Three profiles were drawn on the residual anomaly map along which 2D models of the Mamfe basin were drawn. The modeling was completed in Grav2dc v2.06 software which uses the Talwini’s algorithm and the resulting models gave the depth to basement and the shape of the basement along the profiles. After processing and interpretation, it was deduced that the Mamfe basin has an average length and width of 77.6 km and 29.2 km respectively, an average depth to basement of 5 km and an overall U-shape basement. These dimensions (especially the depth) theoretically create the depth and temperature conditions for petroleum generation. 

scholarly journals New Bouguer Anomaly Map for the Territory of the Slovenia

2021 ◽  
Vol 13 (22) ◽  
pp. 4510
Author(s):  
Klemen Medved ◽  
Oleg Odalović ◽  
Božo Koler
Keyword(s):  
Gravity Anomaly ◽  
Significant Influence ◽  
Bouguer Anomaly ◽  
High Quality ◽  
Digital Terrain ◽  
Terrain Models ◽  
Gravimetric Data ◽  
The Republic ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

The existing Bouguer anomaly map, which covers the territory of the Republic of Slovenia is a few decades old. Since then, quite a few new gravimetric measurements (data) for the territory of Slovenia as well as high quality digital terrain models that are needed for creating such a map have been made available. The methodology and standards for creating gravity anomaly maps are also changing. Thus, the national Bouguer anomaly map was updated. There were some gross errors detected in the set of old gravimetric data. Additionally, the influence of new updated gravimetric data was analyzed. The comparison of the various maps and the analysis of the influence of input gravimetric data indicates that the new gravimetric data of Slovenia has a significant influence on the creation of the gravimetric anomaly maps for Slovenia (even over 30 mGals at some points).

Sign in / Sign up

Export Citation Format

Share Document