An integrated model of the structural evolution of the central Brooks Range foothills, Alaska, using structural geometry, fracture distribution, geochronology, and microthermometry

AAPG Bulletin ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 2245-2274 ◽  
Author(s):  
Alec Duncan ◽  
Catherine Hanks ◽  
Wesley K. Wallace ◽  
Paul B. O'Sullivan ◽  
Thomas M. Parris
Keyword(s):  
Structural Evolution ◽  
Integrated Model ◽  
Structural Geometry ◽  
Brooks Range ◽  
Fracture Distribution

scholarly journals An integrated model for the tectonic development of the frontal Brooks Range and Colville Basin 250 km west of the Trans-Alaska Crustal Transect

1997 ◽  
Vol 102 (B9) ◽  
pp. 20685-20708 ◽  
Author(s):  
Frances Cole ◽  
Kenneth J. Bird ◽  
Jaime Toro ◽  
François Roure ◽  
Paul B. O'Sullivan ◽  
...  
Keyword(s):  
Integrated Model ◽  
Brooks Range ◽  
Tectonic Development ◽  
Crustal Transect

scholarly journals The Internal Structural Evolution of Calderas: Results from 3D Discrete Element Simulations

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 419
Author(s):  
Stuart Hardy
Keyword(s):  
Hazard Analysis ◽  
Structural Evolution ◽  
Element Model ◽  
Discrete Element ◽  
Surface Expression ◽  
Three Dimensions ◽  
Evolutionary Patterns ◽  
Plan View ◽  
Ring Faults ◽  
Fracture Distribution

The structural evolution of calderas is a key issue in volcanology and has profound implications for hazard analysis and the exploitation of geothermal energy and hydrothermal ores. However, their internal geometry at depth and the detailed fault and fracture distribution are unclear and debated. In order to better constrain the internal structural evolution of calderas, I have developed a 3D discrete element model of a frictional cover undergoing piston-like subsidence at its base, simulating magma chamber deflation and cover collapse. I examine two piston geometries, simulating magma chambers with roofs that are circular and rectangular in plan view, to investigate patterns of faulting and subsidence in three dimensions. In both models a complex arrangement of normal and reverse faults accommodates deeper subsidence at higher structural levels. Bell- to cone-shaped, outward-dipping ring faults are consistently the first structures to develop; these faults propagate upwards from the piston edges towards the surface. Later caldera growth is mainly the result of movement on vertical, or steeply inward-dipping, normal ring faults which enclose the earlier reverse faults. As a result, all calderas widen, in terms of their surface expression, with time. The final stage of caldera development includes significant collapse of the caldera walls and transport of this material towards the caldera center. The results confirm that the evolutionary patterns/stages proposed from 2D numerical and analogue models can be generalized to three dimensions, although significant differences between long- and short-axis geometries do occur when the piston is elongate. Compared to 2D simulations, however, 3D results show the geometric complexity of ring faulting, with variations in strain and fault activity at various stages of development demonstrating that often a simple, continuous ring fault structure is not developed.

Structural Evolution Using Seismic Low Frequency Magnitude Approach: A Case Study on Defining Strike-Slip Development in West Natuna Basin, Indonesia

2020 ◽  
Author(s):  
P Riandini
Keyword(s):  
Late Miocene ◽  
Low Frequency ◽  
Structural Evolution ◽  
Late Eocene ◽  
Strike Slip ◽  
Fault System ◽  
3D Seismic ◽  
Structural Geometry ◽  
History Of ◽  
Frequency Magnitude

West Natuna Basin (WNB) is located in the centre of Sunda Shelf in South China Sea; bordered by the Sunda Shelf's basement to the south, the Natuna Arch to the east, and the Khorat Swell to the north. Tectonic evolution of the WNB has imparted a complex structural history of extension, compression and wrenching related to Cenozoic regional tectonic events, for which the structural evolution reflects a history of Late Eocene-Early Oligocene rifting and Middle-Late Miocene inversion. The regional strike-slip movement that associates to the Three Pagodas Fault System has long been recognised at WNB. However, the understanding of this strike-slip behaviour has not previously been investigated despite its important role in reservoir mapping. This study aims to demonstrate how new approaches of seismic attributes analysis combined with structural evolution through palinspastic reconstruction will define the structural geometry as a key point for fault relationship in the production field. Structure map and cross section are generated by integrating wells data and 3D seismic to identify structural trends. Seismic low frequency magnitude has been generated as an attribute to define faults through Spectral Decomposition method. As the faults feature on the seismic are more related to low or even absent of energy, these attributes provide robust attributes to identify four morphology in study area that represent different structural geometry and history. Seismic interpretation shows the structure commences in the early part of the Late Eocene that developed as NE-SW rifting. The rifting is initiated due to creation of pull-apart basins, as part of the WNW-ESE sinistral strike-slip fault development. The major sinistral strike-slip development was accommodated by collision of India that causes onset of rotation of Sundaland. In relation to the oblique NNE-SSW compression, Middle-Late Miocene inversion follows the post-rift deformation. This condition accommodates the development of NW-SE right lateral strike-slip on the marginal fault and result in N-S trending horsetail structure development that plays a role as an essential structure for reservoir trap.This research verifies that the combination between recent re-evaluations of the 3D seismic and its attributes can identify more detailed fault positions to generate better definitions of fault patterns. Therefore, palinspastic restoration becomes one of the classic approaches that brings further comprehension of the fault pattern’s structural evolutions, which leads to the site-development and production’s improvements.

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