scholarly journals Comments on “Anisotropic magnetic susceptibility in the continental lower crust and its implication for the shape of magnetic anomalies” by G. Florio et al.

1994 ◽  
Vol 21 (24) ◽  
pp. 2773-2774 ◽  
Author(s):  
P. Rochette
Keyword(s):  
Magnetic Susceptibility ◽  
Lower Crust ◽  
Magnetic Anomalies ◽  
Continental Lower Crust

Anisotropic magnetic susceptibility in the continental lower crust and its implications for the shape of magnetic anomalies

1993 ◽  
Vol 20 (23) ◽  
pp. 2623-2626 ◽  
Author(s):  
G. Florio ◽  
M. Fedi ◽  
A. Rapolla ◽  
D. M. Fountain ◽  
P. N. Shive
Keyword(s):  
Magnetic Susceptibility ◽  
Lower Crust ◽  
Magnetic Anomalies ◽  
Continental Lower Crust

scholarly journals The Role of Lower Crustal Rheology in Lithospheric Delamination During Orogeny

2021 ◽  
Vol 9 ◽  
Author(s):  
Lin Chen
Keyword(s):  
Lower Crust ◽  
Numerical Models ◽  
The Tibetan Plateau ◽  
Mantle Lithosphere ◽  
Laboratory Studies ◽  
Surface Uplift ◽  
Continental Lower Crust ◽  
Lower Crustal ◽  
Flow Laws

The continental lower crust is an important composition- and strength-jump layer in the lithosphere. Laboratory studies show its strength varies greatly due to a wide variety of composition. How the lower crust rheology influences the collisional orogeny remains poorly understood. Here I investigate the role of the lower crust rheology in the evolution of an orogen subject to horizontal shortening using 2D numerical models. A range of lower crustal flow laws from laboratory studies are tested to examine their effects on the styles of the accommodation of convergence. Three distinct styles are observed: 1) downwelling and subsequent delamination of orogen lithosphere mantle as a coherent slab; 2) localized thickening of orogen lithosphere; and 3) underthrusting of peripheral strong lithospheres below the orogen. Delamination occurs only if the orogen lower crust rheology is represented by the weak end-member of flow laws. The delamination is followed by partial melting of the lower crust and punctuated surface uplift confined to the orogen central region. For a moderately or extremely strong orogen lower crust, topography highs only develop on both sides of the orogen. In the Tibetan plateau, the crust has been doubly thickened but the underlying mantle lithosphere is highly heterogeneous. I suggest that the subvertical high-velocity mantle structures, as observed in southern and western Tibet, may exemplify localized delamination of the mantle lithosphere due to rheological weakening of the Tibetan lower crust.

Analysis of Magnetic Anomaly Characteristics of Underground Non-Coplanar Cross-buried Iron Pipelines

2020 ◽  
Vol 25 (2) ◽  
pp. 223-233
Author(s):  
Pan Wu ◽  
Minghui Wei
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Anomaly ◽  
Magnetic Dipole ◽  
Geomagnetic Field ◽  
Magnetic Anomalies ◽  
Buried Pipelines ◽  
Magnetic Declination ◽  
Magnetic Inclination ◽  
Basic Characteristics ◽  
Geomagnetic Intensity

The non-coplanar cross-buried pipelines are a common way of pipeline wiring. In order to investigate the magnetic anomaly characteristics of the non-coplanar cross-buried pipelines and guide the site operation, the influences of a series of factors on the magnetic anomaly of the non-coplanar cross-buried pipelines are analyzed. Based on the principle of magnetic dipole construction, a forward model is established for the magnetic anomaly characteristics of the subsurface non-coplanar cross-buried pipelines. The basic characteristics of magnetic anomaly for the non-coplanar cross-buried pipelines are defined. The influences of geomagnetic parameters (geomagnetic intensity, geomagnetic inclination, and geomagnetic declination), pipeline parameters (thickness, magnetic susceptibility), and cross angle of pipelines on the characteristics of magnetic anomalies are analyzed. The results show that the shape of the total magnetic anomaly is mainly affected by the magnetic inclination, and the curve of magnetic anomaly at ± I site shows some symmetry. The amplitude is approximately linearly affected by the total geomagnetic field, magnetic declination, pipeline thickness, material magnetic susceptibility, and pipeline cross angle. There is a periodic change of the amplitude with the increase of geomagnetic inclination (−90°–>90°). The crest-trough distance is mainly affected by geomagnetic inclination, magnetic declination, thickness, magnetic susceptibility, and pipeline cross angle. A more accurate measurement can be achieved if the direction of the pipelines is roughly measured and then the number of measurement points is augmented near the intersection of pipelines and the measurement lines. Present work obtains the equivalent magnetic dipole units by segmenting pipelines. The magnetic anomaly characteristics of non-coplanar crossed iron pipelines are successfully simulated. The numerical results are in accordance with the experimental analysis.

Joint Geophysical‐Petrological Modeling on the Ivrea Geophysical Body Beneath Valsesia, Italy: Constraints on the Continental Lower Crust

2020 ◽  
Vol 21 (12) ◽  
Author(s):  
Mattia Pistone ◽  
Luca Ziberna ◽  
György Hetényi ◽  
Matteo Scarponi ◽  
Alberto Zanetti ◽  
...  
Keyword(s):  
Lower Crust ◽  
Continental Lower Crust

Tectono-metamorphic evolution of the Calabria continental lower crust: the case of the Sila Piccola Massif

2020 ◽  
Vol 109 (4) ◽  
pp. 1295-1319 ◽  
Author(s):  
G. Ortolano ◽  
R. Visalli ◽  
E. Fazio ◽  
P. Fiannacca ◽  
G. Godard ◽  
...  
Keyword(s):  
Lower Crust ◽  
Metamorphic Evolution ◽  
Continental Lower Crust

scholarly journals Subhorizontal fabric in exhumed continental lower crust and implications for lower crustal flow: Athabasca granulite terrane, western Canadian Shield

Tectonics ◽  
2010 ◽  
Vol 29 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Gregory Dumond ◽  
Philippe Goncalves ◽  
Michael L. Williams ◽  
Michael J. Jercinovic
Keyword(s):  
Lower Crust ◽  
Canadian Shield ◽  
Continental Lower Crust ◽  
Lower Crustal Flow ◽  
Lower Crustal
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