Influence of basement foliation attitude on geometry of Laramide basement deformation, southern Bridger Range and northern Gallatin Range, Montana

1993 ◽  
pp. 73-88 ◽  
Author(s):  
Erick W. Miller ◽  
David R. Lageson
Keyword(s):  
Basement Deformation

scholarly journals Initial Laramide tectonism recorded by Upper Cretaceous paleoseismites in the northern Bighorn Basin, USA: Field indicators of an applied end load stress

Geology ◽  
2019 ◽  
Vol 47 (11) ◽  
pp. 1059-1063 ◽  
Author(s):  
W.T. Jackson ◽  
M.P. McKay ◽  
M.J. Bartholomew ◽  
D.T. Allison ◽  
D.L. Spurgeon ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
North American Plate ◽  
Plate Boundaries ◽  
Bighorn Basin ◽  
Group Position ◽  
Clastic Dike ◽  
Basement Deformation ◽  
Field Indicators ◽  
Sand Source ◽  
Mesaverde Group

Abstract Soft-sediment deformational structures associated with paleoseismicity (e.g., planar clastic dikes) exist within Upper Cretaceous Mesaverde Group strata in the Laramide Elk Basin anticline, northern Bighorn Basin (Wyoming, USA). Retrodeformation of the Elk Basin anticline to a horizontal Mesaverde Group position indicates that all basement offset is removed and that clastic dikes exhibit a dominant northeast trend. The trend of clastic dikes corresponds to the interpreted northeast-southwest direction of early Laramide layer-parallel shortening, suggesting that the development of clastic dikes recorded initiation of basement deformation and Laramide tectonism. To determine the timing of clastic dike development, we present zircon U-Pb geochronology from the stratigraphically lowest sand-source bed generating upwardly injected clastic dikes and a volcanic bentonite bed (Ardmore bentonite) above the stratigraphic interval containing clastic dikes. Weighted mean ages bracket clastic dike development between 82.4 and 78.0 Ma. Our results imply initiation of basement deformation ∼8–15 m.y. prior than other estimates in the Bighorn Basin. Therefore, we interpret the development of clastic dikes in the Elk Basin anticline to represent an initial phase of Laramide tectonism associated with an applied end load stress transmitted from the southwestern North American plate margin in response to the collision of the conjugate Shatsky Rise oceanic plateau ca. 90–85 Ma. Results demonstrate how sedimentary responses in the foreland can be used to understand tectonic processes at plate boundaries and provide spatial-temporal parameters for models of Laramide deformation.

scholarly journals Extensional Messinian basins in the Central Mediterranean (Calabria, Italy): new stratigraphic and tectonic insights

2018 ◽  
Vol 73 ◽  
pp. 45 ◽  
Author(s):  
Alfonsa Milia ◽  
Maurizio M. Torrente
Keyword(s):  
Water Environment ◽  
Sedimentary Basins ◽  
Normal Faults ◽  
Seismic Profiles ◽  
Rift Basins ◽  
Central Mediterranean ◽  
Tectonic Events ◽  
Basin Subsidence ◽  
Basement Deformation ◽  
Two Stages

The direction of extension and the architecture of the Messinian basins of the Central Mediterranean region is a controversial issue. By combining original stratigraphic analysis of wells and seismic profiles collected offshore and onshore Calabria, we reassess the tectonic evolution that controlled the sedimentation and basement deformation during Messinian times. Three main deep sedimentary basins in the Calabria area record a Messinian succession formed by two clays/shales-dominated subunits subdivided by a halite-dominated subunit. The correlation with the worldwide recognized stratigraphic features permit to define the chronology of the stratigraphic and tectonic events. Three main rift basins that opened in a N-S direction have been recognized. On the contrary a fourth supradetachment basin opened toward the East. We found that the basin subsidence was controlled by two stages of activity of normal faults and that Messinian rift basins evolve in a deep-water environment. The overall pattern of extensional faults of the Central Mediterranean corresponds to normal faults striking parallel to the trench and normal faults striking at an oblique angle to the trench (Fig. 14). In particular in Campania and Calabria regions are present two rifts parallel to trench and an intervening rift orthogonal to the trench. We maintain that the recognized Messinian rift basins can be interpreted according to the “Double-door saloon tectonics”.

scholarly journals Control of Permian and Triassic faults on Alpine basement deformation in the Argentera massif (external southern French Alps)

2003 ◽  
Vol 174 (5) ◽  
pp. 481-496 ◽  
Author(s):  
Jean Delteil ◽  
Jean-François Stephan ◽  
Mikaël Attal
Keyword(s):  
Sedimentary Cover ◽  
Lower Triassic ◽  
Structural Investigations ◽  
French Alps ◽  
Blind Thrust ◽  
Thrust System ◽  
Block Pattern ◽  
Heterogeneous Deformation ◽  
Basement Deformation ◽  
Compressional Strain

Abstract Structural investigations reveal intense and heterogeneous deformation of the sedimentary cover attached to the basement complex of the southern Argentera and Barrot massifs (southernmost External Basement Massifs of the French Alps). Permian and early Triassic syn-depositional extensional tectonics imparted a tilted block pattern to the massifs. An early Miocene first stage of Alpine compression caused pervasive cleavage. This cleavage was controlled by the former pre-existing faults but is nevertheless consistent with NNE contraction. Where regional shortening is orthogonal to the trend of pre-existing faults the pervasive deformation produced either irrotational compressional strain (where no fault inversion occurred), or rotational compressional strain involving syn-cleavage shearing (where faults with favorable paleo-dip were inverted). Where the shortening direction is oblique to the paleo-fault trends, a component of strike-slip movement may locally prevail. A 22 %, N020o directed horizontal shortening, of 11 km, has been calculated based on deformed sedimentary markers in the Permian series and parallel folds in Lower Triassic quartzite. A shallower deformation as brittle reverse faults postdates the cleavage at the southwestern tip of the Argentera Massif and accounts for 4 km of extra shortening. Both types of deformation are connected at depth to a crustal blind thrust system and the Argentera Massif is over-thrust to the south-southwest. The observed strain indicates the Argentera Massif area underwent, from earliest Miocene to Present, a NNE to N rotating compression at distance from the left-lateral southwestern boundary of the Adria block.

BASEMENT DEFORMATION NEAR THE TERMINATION OF A FAILED MAGMATIC CONTINENTAL RIFT: INSIGHTS FROM NORTH-CENTRAL OKLAHOMA

2019 ◽  
Author(s):  
Max Firkins ◽  
◽  
Folarin Kolawole ◽  
Kurt J. Marfurt ◽  
Brett M. Carpenter
Keyword(s):  
Continental Rift ◽  
North Central ◽  
Basement Deformation

Conceptual model of basement deformation beneath the Southern Atlassic front of Tunisia from gravity modeling, seismic reflection profiles and seismotectonic data

2021 ◽  
Author(s):  
Nesrine Frifita ◽  
Mohamed Gharbi ◽  
Kevin Mickus
Keyword(s):  
Seismic Reflection ◽  
Geological Mapping ◽  
Gravity Modeling ◽  
Basement Faults ◽  
Geophysical Study ◽  
Half Graben ◽  
Basement Structures ◽  
Tectonic Style ◽  
Basement Deformation ◽  
Seismic Reflection Profiles

<p>The nature of the basement beneath the Southern Atlassic front of Tunisia is relatively unknown. To study the basement, a geophysical study was undertaken using gravity, seismic reflection and seismicity data. Additionally, these data were used to determine the relationship and the tectonic environment between the known seismicity and basement structures under the Chotts fold belt and the surrounding basins. Based on 2.5D gravity modeling, 2D seismic reflection profiles and known geological mapping, the geometry of the basement was modeled as consisting of horsts,grabens and half-grabens. Specifically, the Sidi Mansour and El-Fejej basins are located on basement uplifts. The variations in the depths of the known earthquakes reveal that the deepest events occurred on basement faults beneath the Metlaoui and Sidi Mansour basins. While the surrounding anticlines within the northern Chotts range are probably inverted into graben and half-graben structures by both thin- and thick-skinned tectonic events. The geophysical findings indicate that the geometry of the basement to consist of a series of uplifted and downdropped regions, where the depth to basement increases from south to north and from east to west. This basement structure can explain the concentration of earthquakes in the northwestern portion of the study area by linking a reactivation of pre-existing east trending fault systems that formed during Alpine Orogeny. The results provide a coherent model showed a mixed thick and thin-skinned tectonic style was active within the study area. </p>

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