BUILDING A UNIFIED TECTONIC MODEL FOR THE TACONIC OROGENY IN THE SOUTHERNMOST APPALACHIANS

2017 ◽  
Author(s):  
James F. Tull ◽  
◽  
Clinton I. Barineau ◽  
Christopher S. Holm-Denoma
Keyword(s):  
Tectonic Model ◽  
Taconic Orogeny

Supplemental material: Cenozoic to Recent plate configurations in the Pacific Basin: Ridge subduction and slab window magmatism in western North America

2006 ◽  
Author(s):  
J.K. Madsen ◽  
D.J. Thorkelson ◽  
R.M. Friedman ◽  
D.D. Marshall
Keyword(s):  
North America ◽  
Pacific Basin ◽  
Western North America ◽  
File Size ◽  
Tectonic Model ◽  
Ridge Subduction ◽  
The Pacific ◽  
Northwestern North America ◽  
Slab Window

Geosphere, February 2006, v. 2, p. 11-34, doi: 10.1130/GES00020.1. Movie 1 - Tectonic model for the Pacific Basin and northwestern North America from 53 Ma to 39 Ma. The file size is 1.3 MB.

Structural development of the Snow Lake Allochthon and its role in the evolution of the southeastern Trans-Hudson Orogen in Manitoba, central Canada

1999 ◽  
Vol 36 (11) ◽  
pp. 1881-1899 ◽  
Author(s):  
Jürgen Kraus ◽  
Paul F Williams
Keyword(s):  
Structural Development ◽  
Southeastern Part ◽  
External Zone ◽  
Local Boundary ◽  
Tectonic Model ◽  
Adjacent Part ◽  
Central Canada ◽  
Tectonic Transport ◽  
The One ◽  
Superior Craton

The Snow Lake Allochthon is a zone of tectonic interleaving of sedimentary rocks of an inverted marginal basin (Kisseynew Domain) with island-arc and oceanic rocks. It is located in the southeastern part of the exposed internal zone of the Paleoproterozoic Trans-Hudson Orogen in Manitoba, Canada, near the external zone (Superior collision zone or Thompson Belt), which constitutes the local boundary between the Trans-Hudson Orogen and the Archean Superior Craton. The Snow Lake Allochthon formed, was deformed, and was metamorphosed up to high grade at low to medium pressure during the Hudsonian orogeny as a result of the collision of Archean cratons ~1.84-1.77 Ga. Four generations of folds (F1-F4) that formed in at least three successive kinematic frames over a period of more than 30 Ma are described. Isoclinal to transposed southerly verging F1-2 structures are refolded by large, open to tight F3 folds and, locally, by open to tight F4 folds. The axes of the F1-2 folds are parallel or near parallel to the axes of F3 folds, owing to progressive reorientation of the F1-2 axes during south- to southwest-directed tectonic transport, followed by F3 refolding around the previous linear anisotropy. A tectonic model is presented that reconciles the distinct tectono-metamorphic developments in the Snow Lake Allochthon and the adjacent part of the Kisseynew Domain on the one hand, and in the Thompson Belt on the other, during final collision of the Trans-Hudson Orogen with the Superior Craton.

Timing of magmatism, foreland basin development, metamorphism and inversion in the Anglo-Brabant fold belt

1997 ◽  
Vol 134 (5) ◽  
pp. 607-616 ◽  
Author(s):  
G. VAN GROOTEL ◽  
J. VERNIERS ◽  
B. GEERKENS ◽  
D. LADURON ◽  
M. VERHAEREN ◽  
...  
Keyword(s):  
Subduction Zones ◽  
Foreland Basin ◽  
Fold Belt ◽  
East Anglia ◽  
Basin Inversion ◽  
Tectonic Model ◽  
The North ◽  
Basin Development ◽  
The North Sea ◽  
And Inversion

New data implying crustal activation of Eastern Avalonia along the Anglo-Brabant fold belt are presented. Late Ordovician subduction-related magmatism in East Anglia and the Brabant Massif, coupled with accelerated subsidence in the Anglia Basin and in the Brabant Massif during Silurian time, indicate a foreland basin development. Final collision resulted in folding, cleavage development and thrusting during the mid-Lochkovian to mid-Eifelian. In the southeast of the Anglo-Brabant fold belt, Acadian deformation produced basin inversion and the regional antiformal structure of the Brabant Massif. The uplift, inferred from the sedimentology, petrography and reworked palynomorphs in the Lower Devonian of the Dinant Synclinorium is confirmed by illite crystallinity studies. The tectonic model discussed implies the presence of two subduction zones in the eastern part of Eastern Avalonia, one along the Anglo-Brabant fold belt and another under the North Sea in the prolongation of the North German–Polish Caledonides.

Focal mechanisms of earthquakes related to the 29 November 1975 Kalapana, Hawaii, earthquake: The effect of structure models

1981 ◽  
Vol 71 (3) ◽  
pp. 713-729 ◽  
Author(s):  
R. S. Crosson ◽  
E. T. Endo
Keyword(s):  
Main Shock ◽  
Horizontal Layer ◽  
Focal Mechanisms ◽  
Local Network ◽  
The South ◽  
Low Velocity ◽  
Tectonic Model ◽  
Low Velocity Layer ◽  
Using Data ◽  
Velocity Layer

abstract Initial focal mechanism determinations for the 29 November 1975 Kalapana, Hawaii, earthquake indicated discrepancy between the mechanism determined from teleseismic data by Ando and the mechanism determined using data from the local U.S. Geological Survey network surrounding the epicenter region. The resolution of this difference is crucial to correctly understand this earthquake, as well as to understand the tectonics of the south flank of Kilauea volcano. When a model with a low-velocity layer at the base of the crust is used for projection back to the focal sphere for the local network mechanisms, the discrepancy vanishes. To further investigate this result, focal mechanisms were determined using several contrasting models for a set of well-recorded earthquakes. A large number of these earthquakes have mechanisms identical to the main shock when the low-velocity layer model is used. Dispersion of P and T axes is also minimized by use of this model. A low-angle slip direction, favored for the main shock and typical of most other solutions, exhibits remarkable stability normal to the east rift zone of Kilauea. Our results suggest a tectonic model, similar in nature to that proposed by Ando, in which the south flank of Kilauea consists of a mobile block of crust which is relatively free to move laterally on a low-strength zone at about 10 km depth. Forceful injection of magma along the rift zones provides the loading stress which is released by catastrophic failure in the weak, horizontal layer in a cycle of perhaps 100 yr.

A model for Archean tectonism. Part 2. Numerical models of vertical tectonism in greenstone belts

1980 ◽  
Vol 17 (1) ◽  
pp. 60-71 ◽  
Author(s):  
Jean-Claude Mareschal ◽  
Gordon F. West
Keyword(s):  
Numerical Models ◽  
Volcanic Eruptions ◽  
Crustal Rocks ◽  
Tectonic Model ◽  
Mechanical Evolution ◽  
Accumulated Strain ◽  
Lava Sequence ◽  
Order Of Magnitude ◽  
Greenstone Belts ◽  
Horizontal Temperature Gradients

A tectonic model that attempts to explain common features of Archean geology is investigated. The model supposes the accumulation, by volcanic eruptions, of a thick basaltic pile on a granitoid crust. The thermal blanketing effect of this lava raises the temperature of the granitic crust and eventually softens it enough that gravitational slumping and downfolding of the lava follows.Numerical models of the thermal and mechanical evolution of a granitoid crust covered with a thick lava sequence indicate that such an evolution is possible when reasonable assumptions are made about the temperature dependence of the viscosity in crustal rocks. These models show the lava sinking in relatively narrow regions while wider granite diapirs appear in between. The convection produces strong horizontal temperature gradients that may cause lateral changes in metamoprhic facies. A one order of magnitude drop in accumulated strain occurs between the granite–basalt interface and the center of the granite diaper at a depth of 10–15 km.

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