scholarly journals Three-dimensional density model of the Nazca plate and the Andean continental margin

2006 ◽  
Vol 111 (B9) ◽  
Author(s):  
Andrés Tassara ◽  
Hans-Jürgen Götze ◽  
Sabine Schmidt ◽  
Ron Hackney
Keyword(s):  
Continental Margin ◽  
Three Dimensional ◽  
Density Model ◽  
Nazca Plate

scholarly journals Magnetotelluric study in the Los Lagos Region (Chile) to investigate volcano-tectonic processes in the Southern Andes

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Maria Jose Segovia ◽  
Daniel Diaz ◽  
Katarzyna Slezak ◽  
Felipe Zuñiga
Keyword(s):  
Electrical Resistivity ◽  
Three Dimensional ◽  
Phase Changes ◽  
Fault System ◽  
Electrical Anisotropy ◽  
Mountain Range ◽  
Southern Andes ◽  
Nazca Plate ◽  
First Results ◽  
Dimensional Parameters

AbstractTo analyze the process of subduction of the Nazca and South American plates in the area of the Southern Andes, and its relationship with the tectonic and volcanic regime of the place, magnetotelluric measurements were made through a transversal profile of the Chilean continental margin. The data-processing stage included the analysis of dimensional parameters, which as first results showed a three-dimensional environment for periods less than 1 s and two-dimensional for periods greater than 10 s. In addition, through the geomagnetic transfer function (tipper), the presence of structural electrical anisotropy was identified in the data. After the dimensional analysis, a deep electrical resistivity image was obtained by inverting a 2D and a 3D model. Surface conductive anomalies were obtained beneath the central depression related to the early dehydration of the slab and the serpentinization process of the mantle that coincides in location with a discontinuity in the electrical resistivity of a regional body that we identified as the Nazca plate. A shallow conductive body was located around the Calbuco volcano and was correlated with a magmatic chamber or reservoir which in turn appears to be connected to the Liquiñe Ofqui fault system and the Andean Transverse Fault system. In addition to the serpentinization process, when the oceanic crust reaches a depth of 80–100 km, the ascending fluids produced by the dehydration and phase changes of the minerals present in the oceanic plate produce basaltic melts in the wedge of the subcontinental mantle that give rise to an eclogitization process and this explains a large conductivity anomaly present beneath the main mountain range.

Surface sediments of the Peru-Chile continental margin and the Nazca plate

1980 ◽  
Vol 91 (6) ◽  
pp. 321 ◽  
Author(s):  
LAWRENCE A. KRISSEK ◽  
KENNETH F. SCHEIDEGGER ◽  
LAVERNE D. KULM
Keyword(s):  
Continental Margin ◽  
Surface Sediments ◽  
Nazca Plate

Technology for constructing a 3D density model of the earth's crust in the INTEGRO GIS

2020 ◽  
pp. 38-51
Author(s):  
V.A. Spiridonov ◽  
◽  
N.N. Pimanova ◽  
M.Ya. Finkelstein ◽  
◽  
...  
Keyword(s):  
Inverse Problem ◽  
Key Words ◽  
Software Package ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Density Model ◽  
Technology Application ◽  
Key Words Density ◽  
Model Inverse ◽  
Density Modeling

The work is devoted to the construction of a three-dimensional density model of the territory, which would not contradict the information obtained by other methods (drilling, seismic, etc.). A generalized scheme for constructing such a model is given, its stages and ways of matching with the results of other methods are described. The technology described in the work is based on the tools included in the GIS INTEGRO software package (FSBI "VNIGNI"). The article is illustrated with examples of the technology application in the construction of density models for various parts of the Volga-Ural oil and gas province. Key words: density modeling, 3D density model, inverse problem of gravity exploration, GIS INTEGRO.

scholarly journals Magnetoteluric Study in the Region De Los Lagos to Study Volcano-Tectonic Processes in the Southern Andes

2020 ◽  
Author(s):  
Maria Jose Segovia Baldovino ◽  
Daniel Diaz Alvarado ◽  
Katarzyna Slezak ◽  
Felipe Zuñiga Armijo
Keyword(s):  
Electrical Resistivity ◽  
Three Dimensional ◽  
Phase Changes ◽  
Fault System ◽  
Electrical Anisotropy ◽  
Mountain Range ◽  
Southern Andes ◽  
Nazca Plate ◽  
First Results ◽  
Dimensional Parameters

Abstract In order to analyze the process of subduction of the Nazca and South American plates in the area of the Southern Andes, and its relationship with the tectonic and volcanic regime of the place, magnetotelluric measurements were made through a transversal profile of the Chilean continental margin. The data processing stage included the analysis of dimensional parameters, which as first results showed a three-dimensional environment for periods less than 1s and two-dimensional for periods greater than 10s. In addition, through the geomagnetic transfer function (tipper), the presence of structural electrical anisotropy was identified in the data. After the dimensional analysis, a deep electrical resistivity image was obtained by inverting a 2D and a 3D model. Surface conductive anomalies were obtained beneath the central depression related to the early dehydration of the slab and the serpentinization process of the mantle that coincides in location with a discontinuity in the electrical resistivity of a regional body that we identified as the Nazca plate. A shallow conductive body was located around the Calbuco volcano and was correlated with a magmatic chamber or reservoir which in turn appears to be connected to the Liquiñe Ofqui fault system and the Andean Transverse Fault system. In addition to the serpentinization process, when the oceanic crust reaches a depth of 80-100km, the ascending fluids produced by the dehydration and phase changes of the minerals present in the oceanic plate produce basaltic melts in the wedge of the subcontinental mantle that give rise to an eclogitization process and this explains a large conductivity anomaly present beneath the main mountain range.

On: “Inversion of gravity profiles by use of a Backus‐Gilbert approach” by William R. Green (GEOPHYSICS, October 1975, p. 763–772).

Geophysics ◽  
1976 ◽  
Vol 41 (4) ◽  
pp. 777-777
Author(s):  
Ramesh Chander
Keyword(s):  
Gravity Anomaly ◽  
Total Mass ◽  
Gravity Data ◽  
Unit Length ◽  
Three Dimensional ◽  
Density Model ◽  
Dimensional Case ◽  
Two Dimensional ◽  
Mass Excess ◽  
Seminal Paper

An important possible constraint on a density model obtained from inversion of gravity data has been overlooked in the seminal paper by Green. The computed density model should be such that the corresponding total mass excess or deficit per unit length in a two‐dimensional case, or total mass excess or deficit in a three‐dimensional case, should be comparable to the value obtained by applying Gauss’s theorem to the observed gravity anomaly data (Grant and West, 1965, p. 227–28 and p. 232).

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