scholarly journals MeltMigrator: A MATLAB-based software for modeling three-dimensional melt migration and crustal thickness variations at mid-ocean ridges following a rules-based approach

2017 ◽  
Vol 18 (1) ◽  
pp. 445-456
Author(s):  
Hailong Bai ◽  
Laurent G. J. Montési ◽  
Mark D. Behn
Keyword(s):  
Three Dimensional ◽  
Crustal Thickness ◽  
Melt Migration ◽  
Ocean Ridges ◽  
Thickness Variations

Regional crustal thickness variations of the Peninsular Ranges, southern California

Geology ◽  
2000 ◽  
Vol 28 (4) ◽  
pp. 303-306
Author(s):  
Jennifer L. Lewis ◽  
Steven M. Day ◽  
Harold Magistrale ◽  
Jennifer Eakins ◽  
Frank Vernon
Keyword(s):  
Southern California ◽  
Crustal Thickness ◽  
Peninsular Ranges ◽  
Thickness Variations

Mesozoic salt tectonics in the Toulon Belt, Eastern Provence : Inversion of a salt-rich fault zone

2021 ◽  
Author(s):  
Vincent Wicker ◽  
Mary Ford
Keyword(s):  
Fault Zone ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Three Dimensional ◽  
Complex Salt ◽  
Salt Diapir ◽  
Lateral Migration ◽  
Northern Flank ◽  
Northern Margin ◽  
Thickness Variations

<p>Detailed structural and stratigraphic field mapping is used to reconstruct the Jurassic to Late Cretaceous diapiric and tectonic evolution of the Toulon Fault Zone, eastern Beausset Syncline and Toulon Belt, southern France, which represents the easternmost vestige of the Pyrenean orogen in Provence. This complex salt-rich area records a complete history from Jurassic-early Cretaceous subsidence and Aptian-Albian oblique rifting to Late Cretaceous Pyrenean-Provençal shortening. Halokinetic sequences and geometries were preserved principally on the northern flank of the Mont Caume salt diapir sourced from the Upper Triassic Keuper unit. Our field observations are best explained by a model where halokinetic activity interacted with regional deviatoric stresses from early-Jurassic to Santonian/Campanian times. Halokinetic wedges of Jurassic and Early Cretaceous carbonates thin toward the diapir, recording early salt mobilisation. Inverted relics of Apto-Albian rift depocenters are aligned along the northern margin of the Toulon Belt and the adjacent Bandol belt that lies to the west.  The Turonian-Coniacian Revest depocenter developed due to localized strong asymmetrical growth of the Mont Caume diapir. The three-dimensional form and growth of the diapir controlled lateral migration of the Revest depocenter, thickness variations, progressive unconformities, and the westward increase in stratal overturning of a flap. A component of N-S compression with related accelerated halokinetic activity can explain our observations and can be considered as the earliest expression of N-S convergence in the Provencal fold belt.  Further west, the overturned Beausset klippe can be interpreted as the remnant of a megaflap on the northern flank of the Bandol diapir. The Toulon belt salt structures are excellent field analogues to others observed in the external Alps and Pyrenees.</p>

Three-dimensional strain accumulation and partitioning in an arcuate orogenic wedge: An example from the Himalaya

2020 ◽  
Vol 133 (1-2) ◽  
pp. 3-18 ◽  
Author(s):  
Suoya Fan ◽  
Michael A. Murphy
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Western Himalaya ◽  
Shear Zones ◽  
High Elevation ◽  
Central Himalaya ◽  
Structural Style ◽  
Orogenic Wedge ◽  
Oblique Convergence ◽  
Thickness Variations

Abstract In this study, we use published geologic maps and cross-sections to construct a three-dimensional geologic model of major shear zones that make up the Himalayan orogenic wedge. The model incorporates microseismicity, megathrust coupling, and various derivatives of the topography to address several questions regarding observed crustal strain patterns and how they are expressed in the landscape. These questions include: (1) How does vertical thickening vary along strike of the orogen? (2) What is the role of oblique convergence in contributing to along-strike thickness variations and the style of deformation? (3) How do variations in the coupling along the megathrust affect the overlying structural style? (4) Do lateral ramps exist along the megathrust? (5) What structural styles underlie and are possibly responsible for the generation of high-elevation, low-relief landscapes? Our model shows that the orogenic core of the western and central Himalaya displays significant along-strike variation in its thickness, from ∼25–26 km in the western Himalaya to ∼34–42 km in the central Himalaya. The thickness of the orogenic core changes abruptly across the western bounding shear zone of the Gurla Mandhata metamorphic core complex, demonstrating a change in the style of strain there. Pressure-temperature-time results indicate that the thickness of the orogenic core at 37 Ma is 17 km. Assuming this is constant along strike from 81°E to 85°E indicates that, the western and central Nepal Himalaya have been thickened by 0.5 and 1–1.5 times, respectively. West of Gurla Mandhata the orogenic core is significantly thinner and underlies a large 11,000 km2 Neogene basin (Zhada). A broad, thick orogenic core associated with thrust duplexing is collocated with an 8500 km2 high-elevation, low-relief surface in the Mugu-Dolpa region of west Nepal. We propose that these results can be explained by oblique convergence along a megathrust with an along-strike and down-dip heterogeneous coupling pattern influenced by frontal and oblique ramps along the megathrust.

scholarly journals Crustal thickness variations in the Aegean region and implications for the extension of continental crust

2006 ◽  
Vol 111 (B1) ◽  
Author(s):  
Lupei Zhu ◽  
Brian J. Mitchell ◽  
Nihal Akyol ◽  
Ibrahim Cemen ◽  
Kivanc Kekovali
Keyword(s):  
Continental Crust ◽  
Crustal Thickness ◽  
Aegean Region ◽  
Thickness Variations
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