Integrated seismic and gravimetric model of Jocolí Basin, Argentina

2014 ◽  
Vol 2 (2) ◽  
pp. T57-T68
Author(s):  
Patricia Martinez ◽  
Mario Gimenez ◽  
Andres Folguera ◽  
Federico Lince Klinger

Gravity measurements and reinterpretations of previously released seismic lines were made, focusing on the provincial border between neighboring provinces San Juan and Mendoza. A Bouguer anomaly map was obtained after the processing of gravimetric data, which were previously filtered, to obtain the Bouguer residual anomalies used for studying the geologic structures located on the upper crust. The analysis of these Bouguer residual anomalies allowed identification of the Jocolí Basin in a foreland position within a triangle zone at the boundary of the Precordillera fold-and-thrust belt with the Sierras Pampeanas thick-skinned foreland province. The seismic images allowed interpretation of three horizons: Paleozoic, Triassic, and Tertiary-Quaternary ages. The authors have reinterpreted the seismic and well data and reconstructed gravity models for the area under study aiming at unraveling the deep structure of the region and identifying features with potential for oil and gas exploration.

2017 ◽  
Vol 47 (1) ◽  
pp. 3-19
Author(s):  
João Gabriel Motta ◽  
Norberto Morales ◽  
Walter Malagutti Filho

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.


2021 ◽  
Author(s):  
Pantelis Soupios ◽  
Alexandros Stampolidis ◽  
Maurizio Fedi ◽  
SanLinn Kaka ◽  
Khalid Al-Ramadan ◽  
...  

Abstract The study area is a part of Dammam Dome that is situated at King Fahd University of Petroleum & Minerals (KFUPM) campus, Dhahran, Kingdom of Saudi Arabia. The gravity survey was conducted as a pilot case study to explore part of Dammam Dome in greater detail. Gravity data were collected solely during night hours due to low noise levels. A significant part of the survey was conducted during the summer holiday period, , when there was no student are on campus. A total of 235 gravity measurements were made using a Scintrex CG5 gravitometer, while a Trimble R10+ differential GPS (DGPS) was used to measure the stations’ location and elevation with the highest accuracy. All gravity data were reduced using several algorithms, and their outcomes were cross-compared. The Complete Bouguer anomaly map for the campus was then generated. Several enhancement filters including edged detection and shallow to deeper source separation were applied. Data were inverted, and 2.5D and 3D models were created to image the subsurface conditions. The main purpose of this study is to better understand the subsurface geology, tectonic settings of the Dammam Dome by applying the high-resolution gravity method before carrying out any comprehensive geophysical (seismic) 3D survey.


1990 ◽  
Vol 27 (2) ◽  
pp. 187-199 ◽  
Author(s):  
M. M. Kehlenbeck ◽  
S. P. Cheadle

In this study, gravity data from 350 new gravity stations are combined with those from 50 previously surveyed stations in a detailed Bouguer anomaly map of a portion of the Quetico and Wawa subprovinces north and west of Thunder Bay, Ontario.In general, high gravity values characterize the southern and southwestern part of the area where metavolcanic rocks of the Wawa subprovince dominate. Much of the Quetico subprovince forms a broad gravitational low, reflecting extensive exposures of gneisses, schists, and migmatites. Well-defined gravity lows are associated with several granitic intrusive bodies.Three- and [Formula: see text]-dimensional gravity models of subsurface configuration of the density contrasts, representative of major rock units, indicate a trough-like structure for the metavolcanic rocks of the Wawa subprovince. This trough-like structure is flanked by a domical feature in the granitoid rocks to the south. North of the metavolcanic rocks, a succession of low-grade greywackes and slates occupies a basinal structure. These structures form the principal subsurface elements of the Wawa subprovince in this area.The gneisses, schists, and migmatites of the Quetico subprovince form a thick, southward-dipping, wedge-shaped structure that may extend under the structures of the Wawa subprovince. This wedge-shaped structure is underlain by a model unit of greater density representative of mafic gneisses and amphibolites. The denser substratum is modelled with local abrupt changes in dip corresponding in position with the Quetico and Hawkeye Lake faults.


2018 ◽  
Vol 40 (3) ◽  
pp. 1063 ◽  
Author(s):  
S. Chailas ◽  
A. Tzanis ◽  
E. Lagios

This work presents the results of a high resolution gravity survey conducted in the area of Marathon Basin to asses the structure of the basement. A total of 120 gravity stations were measured. Standard data reduction procedures were followed, albeit based on modern, high precision techniques. The inversion of the Bouguer anomaly map provided a rather detailed image of the basement topography completing the information available from surface geological and morphological surveys. The major structural features of the Marathon Basin appear to be controlled by a system of NE-SW neotectonic faults causing stepwise NW-SE deepening of the basement to a maximum detectable depth of~450m. These faults, together with a system of NW-SE major, and a host of minor faulting features, lend to the Basin characteristics of a Riedel structure formed by a predominantly N-S extensional field effecting clockwise block rotation. This mode of deformation may also have facilitated the formation of local anticlinal/ synclinal structures, which endow the area with its rather complicated morphology. Finally, the multiple intersecting faults appear to form a permeable network, presumably responsible for the salination of the local aquifer system; the NE-SW major normal faults may the most significant contributor to this effect.


Geophysics ◽  
1980 ◽  
Vol 45 (7) ◽  
pp. 1153-1163 ◽  
Author(s):  
Salah I. El‐Batroukh ◽  
Ahmed S. Zentani

A Bouguer anomaly map of Raguba oil field and the surrounding areas is presented and interpreted. The main features of the map are: (1) A belt of positive anomalies approaching Bouguer values of 3 mgal in the field area then increasing up to 9 mgal toward the northwest. (2) Negative Bouguer values of −20 mgal on the east and west sides and a negative value of −13 mgal on the northeast side of the field. (3) Steep anomaly gradients trending north‐south on both sides of the field. To the north, the trend takes a northwest direction. (4) All these anomalies are superimposed on a regional trend of 0.16 mgal/km negative toward the south. The positive belt is interpreted as a horst structure characterized by crystalline basement at shallow depths. The negative anomalies are due to the density contrast between the sediments and the basement. Structural sections along certain profiles are presented and used for constructing gravity models calculated by computer.


2021 ◽  
Vol 225 (2) ◽  
pp. 984-997
Author(s):  
Álvaro Osorio Riffo ◽  
Guillaume Mauri ◽  
Adriano Mazzini ◽  
Stephen A Miller

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.


2018 ◽  
Vol 7 (1) ◽  
pp. 94
Author(s):  
Anatole Eugene Djieto Lordon ◽  
Mbohlieu YOSSA ◽  
Christopher M Agyingi ◽  
Yves Shandini ◽  
Thierry Stephane Kuisseu

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. 


2021 ◽  
Vol 13 (22) ◽  
pp. 4510
Author(s):  
Klemen Medved ◽  
Oleg Odalović ◽  
Božo Koler

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).


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