Structural evolution of a major fault zone: the Cape Ray Fault Zone, southwestern Newfoundland, Canada

The Cape Ray Fault Zone is a major Paleozoic structure in southwestern Newfoundland, and occurs at or close to the boundary between two major continental blocks, Laurentia and Avalonia. A detailed structural analysis demonstrates that the fault records early reverse-sinistral thrusting of the Grand Bay Complex at amphibolite grade (D2), followed by a protracted event (D3) characterized by reverse-dextral thrusting of the Grand Bay Complex rocks on top of the supracrustal rocks of the Windsor Point Group and retrogression to greenschist facies, as well as a pre-384 Ma orogen-parallel dextral transcurrent mylonite (D4) during the later stages of the collision. Regional-scale strain partitioning induced heterogeneity of strain both along and across the strike of the Cape Ray Fault Zone. The east–west-oriented segment of the Cape Ray Fault Zone is a tear fault that accommodated differential displacement along the length of the fault. Later stages of the deformation include post-384 Ma sinistral transcurrent reactivation of the dextral mylonite and extension. The reverse-sinistral thrusting and the reverse-dextral motion occurred between 415 and 386 Ma and correspond to the two-phase Acadian orogeny recognized at the scale of the orogen and believed to be related to collision between Laurentia and Avalonia. The Cape Ray Fault Zone preserves evidence of large-scale geodynamic processes affecting rocks where the kinematics and the timing are well constrained.

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Two-phase late Paleozoic magmatism (~ 313–312 and ~ 299–298 Ma) in the Lusatian Block and its relation to large scale NW striking fault zones: evidence from zircon U–Pb CA–ID–TIMS geochronology, bulk rock- and zircon chemistry

International Journal of Earth Sciences ◽

10.1007/s00531-021-02092-y ◽

2021 ◽

Author(s):

A. Käßner ◽

M. Tichomirowa ◽

M. Lapp ◽

D. Leonhardt ◽

M. Whitehouse ◽

...

Keyword(s):

Fault Zone ◽

Large Scale ◽

Age Groups ◽

Spatial Relation ◽

Shear Zones ◽

Igneous Rocks ◽

Geochemical Data ◽

Late Paleozoic ◽

Two Phase ◽

Saxothuringian Zone

AbstractLate Paleozoic (Variscan) magmatism is widespread in Central Europe. The Lusatian Block is located in the NE Bohemian Massif and it is part of the Saxothuringian Zone of the Variscan orogen. It is bordered by two major NW-trending shear zones, the Intra-Sudetic Fault Zone towards NE and the Elbe Fault Zone towards SW. The scarce Variscan igneous rocks of the Lusatian Block are situated close to these faults. We investigated 19 samples from Variscan plutonic and volcanic rocks of the Lusatian Block, considering all petrological varieties (biotite-bearing granites from the Koenigshain and Stolpen plutons, amphibole-bearing granites from three boreholes, several volcanic dykes, and two volcanites from the intramontane Weissig basin). We applied whole-rock geochemistry (18 samples) and zircon evaporation dating (19 samples). From the evaporation data, we selected six representative samples for additional zircon SHRIMP and CA–ID–TIMS dating. For the Koenigshain pluton, possible protoliths were identified using whole-rock Nd-isotopes, and zircon Hf- and O-isotopes. The new age data allow a subdivision of Variscan igneous rocks in the Lusatian Block into two distinct magmatic episodes. The spatial relation of the two age groups to either the Elbe Fault Zone (298–299 Ma) or the Intra-Sudetic Fault Zone (312–313 Ma) together with reports on the fault-bound character of the dated intrusions suggests an interpretation as two major post-collisional faulting episodes. This assumption of two distinct magmatic periods is confirmed by a compilation of recently published zircon U–Pb CA–ID–TIMS data on further Variscan igneous rocks from the Saxothuringian Zone. New geochemical data allow us to exclude a dominant sedimentary protolith for the Koenigshain pluton as supposed by previous investigations. This conclusion is mainly based on new O- and Hf-isotope data on zircon and the scarcity of inherited zircons. Instead, acid or intermediate igneous rocks are supposed as the main source for these I-type granitoids from the Koenigshain pluton.

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Structural evolution of a crustal-scale seismogenic fault in a magmatic arc: The Bolfin Fault Zone (Atacama Fault System)

10.5194/egusphere-egu21-3093 ◽

2021 ◽

Author(s):

Simone Masoch ◽

Rodrigo Gomila ◽

Michele Fondriest ◽

Erik Jensen ◽

Tom Mitchell ◽

...

Keyword(s):

Fault Zone ◽

Large Scale ◽

Damage Zone ◽

Structural Evolution ◽

Crystalline Basement ◽

Fault System ◽

Fault Mechanics ◽

Seismogenic Fault ◽

Magmatic Arc ◽

Atacama Fault System

The nucleation and evolution of major crustal-scale seismogenic faults in the crystalline basement as well as the process of strain localization represent a long-standing, but poorly understood, issue in structural geology and fault mechanics. Here, we addressed the spatio-temporal evolution of the Bolfin Fault Zone (BFZ), a >40-km-long exhumed seismogenic splay fault of the 1000-km-long strike-slip Atacama Fault System. The BFZ has a sinuous fault trace across the Mesozoic magmatic arc of the Coastal Cordillera (Northern Chile). Seismic faulting occurred at 5-7 km depth and &#8804; 270 &#176;C in a fluid-rich environment as recorded by extensive propylitic alteration and epidote-chlorite veining. The ancient (125-118 Ma) seismicity is attested by the widespread occurrence of pseudotachylytes both in the fault core and in the damage zone. Field geological surveys indicate nucleation of the BFZ on precursory geometrical anisotropies represented by magmatic foliation of plutons (northern and central segments) and andesitic dyke swarms (southern segment) within the heterogeneous crystalline basement. Faulting exploited the segments of precursory anisotropies that were favorably oriented with respect to the long-term stress field associated with the oblique ancient subduction. The large-scale sinuous geometry of the BFZ may result from linkage of these anisotropy-pinned segments during fault growth. This evolution may provide a model to explain the complex fault pattern of the crustal-scale Atacama Fault System.

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Large-scale flat-lying mafic intrusions in the granitic Baltica crust of central Sweden and implications for basement deformation during Caledonian orogeny

10.5194/egusphere-egu21-6121 ◽

2021 ◽

Author(s):

Rodolphe Lescoutre ◽

Bjarne Almqvist ◽

Hemin Koyi ◽

Olivier Galland ◽

Peter Hedin ◽

...

Keyword(s):

Large Scale ◽

Regional Scale ◽

Structural Evolution ◽

Shear Zones ◽

Mafic Intrusions ◽

Scandinavian Caledonides ◽

Caledonian Orogeny ◽

Crustal Shear Zones ◽

Structural Architecture ◽

Basement Deformation

The role of inheritance in localizing basement deformation in the foreland has been demonstrated in orogens in different parts of the world. In the external domain of the central Scandinavian Caledonides, questions remain about the amount and the distribution of deformation accommodated by the Baltica basement during Caledonian orogeny. However, to answer these questions, it is necessary to understand the architecture of the Baltica crust underneath the Caledonian nappes and to determine the occurrence of potential detachment horizons or inherited structures that accommodated the shortening.In this work, we study the lithological and structural architecture of the Baltica basement in central Sweden, east and west of the present-day Caledonian front. The aim is twofold: 1) identifying the main geological features of the Fennoscandian Shield and their regional extent underneath the Caledonian nappes to the west, and 2) to address their role in accommodating deformation during Caledonian orogeny.The study area is characterized by mainly ~1.8 Ga granitic bodies intruded by various generations of mafic intrusions and locally bounded by major crustal shear zones. On the one hand, based on seismic interpretations, magnetic and gravimetry forward modeling and mapping, and results from the recently drilled COSC-2 borehole (as part of the Collisional Orogeny in the Scandinavian Caledonides (COSC) drilling project), we show that the basement underlying the Caledonian nappes is characterized by inclined to sub-horizontal mafic intrusions with large extent, emplaced at mid-crustal level. We propose that these intrusions are similar in size, geometry, and potentially age, to the 1.25 Ga Central Scandinavian Dolerite Group (CSDG) that are mapped as 100&#8217;s km long elliptic bodies or described as saucer-shaped intrusions further east. On the other hand, based on observations from COSC-2 drill cores and previous studies, analogue modelling and 2D seismic restoration, we propose that favorably oriented intrusions influenced, at least partly, crustal shortening in this area by localizing deformation along their margins. At a regional scale, we discuss the distribution of thick-skinned and thin-skinned deformation at the present-day orogenic front. On a broader scale, this study raises the question regarding the influence of pre-existing mafic intrusions in controlling the structural evolution and the segmentation of orogenic or rift systems in general.

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Permeability contrasts of fault zones - from conceptual model to numerical simulation

10.5194/egusphere-egu2020-6520 ◽

2020 ◽

Author(s):

Ulrich Kelka ◽

Thomas Poulet ◽

Luk Peeters

Keyword(s):

Fluid Flow ◽

Fault Zone ◽

Large Scale ◽

Regional Scale ◽

Damage Zone ◽

Fluid Pressure ◽

Fault Zones ◽

Strong Impact ◽

Fault Zone Architecture ◽

The Impact

Fault and fracture networks can govern fluid flow patterns in the subsurface and predicting fluid flow on a regional scale is of interest in a variety of fields like groundwater management, mining engineering, energy, and mineral resources. Especially the pore fluid pressure can have a strong impact on the strength of fault zones and might be one of the drivers for fault reactivation. Reliable simulations of the transient changes in fluid pressure need to account for the generic architecture of fault zones that comprises strong permeability contrast between the fault core and damage zone.Particularly, the distribution and connectivity of large-scale fault zones can have a strong impact on the flow field. Yet, modelling numerically such features in their full complexity remains challenging. Often faults zones are conceptualized as forming exclusively either barriers or conduits to fluid flow. However, a generic architecture of fault zones often comprises a discrete fault core surrounded by a diffuse damage zone and conceptualizing large scale discontinuities simply as a barrier or conduit is unlikely to capture the regional scale fluid flow dynamics. It is known that if the fault zone is hosted in low-permeability strata, such as clays or crystalline rocks, a transversal flow barrier can form along the fault core whereas the fracture-rich fault damage zone represents a longitudinal conduit. In more permeable host-rocks (i.e. sandstones or carbonates) the reverse situation can occur, and the permeability distributions in the damage zones can be governed by the abundance of low-permeability deformation features. A reliable numerical model needs to account for the difference and strong contrasts in fluid flow properties of the core and the damage zone, both transversally and longitudinally, in order to make prediction about the regional fluid flow pattern.Here, we present a numerical method that accounts for the generic fault zone architecture as lower dimensional interfaces in conforming meshes during fluid flow simulations in fault networks. With this method we aim to decipher the impact of fault zone architecture on subsurface flow pattern and fluid pressure evolution in fractures and faulted porous media. The method is implemented in a finite element framework for Multiphysics simulations. We demonstrate the impact of considering the more generic geological structure of individual faults on the flow field by conceptualizing discontinuities either as barriers, conduits or as a conduit-barrier system and show were these conceptualizations are applicable in natural systems. We further show that a reliable regional scale fluid flow simulation in faulted porous media needs to account for the generic fault zone architecture. The approach is finally used to evaluate the fluid flow response of statistically parameterised faulted media, in order to investigate the impact and sensitivity of each variable parameter.

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A two-phase heuristic algorithm to solve the large-scale vehicle routing problem

International Technology and Innovation Conference 2006 (ITIC 2006) ◽

10.1049/cp:20061159 ◽

2006 ◽

Cited By ~ 1

Author(s):

Wu Zengyuan ◽

Wu Xiaobo ◽

Fang Gang ◽

Wu Bei

Keyword(s):

Vehicle Routing ◽

Heuristic Algorithm ◽

Vehicle Routing Problem ◽

Large Scale ◽

Two Phase ◽

Routing Problem

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Thermoelectric Properties of Thin Films from Sorted Single-Walled Carbon Nanotubes

Materials ◽

10.3390/ma13173808 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3808 ◽

Cited By ~ 3

Author(s):

Blazej Podlesny ◽

Bogumila Kumanek ◽

Angana Borah ◽

Ryohei Yamaguchi ◽

Tomohiro Shiraki ◽

...

Keyword(s):

Carbon Nanotubes ◽

Thermoelectric Properties ◽

Large Scale ◽

Single Walled Carbon Nanotubes ◽

Parent Material ◽

Free Standing ◽

Two Phase ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes ◽

Aqueous Two Phase Extraction

Single-walled carbon nanotubes (SWCNTs) remain one of the most promising materials of our times. One of the goals is to implement semiconducting and metallic SWCNTs in photonics and microelectronics, respectively. In this work, we demonstrated how such materials could be obtained from the parent material by using the aqueous two-phase extraction method (ATPE) at a large scale. We also developed a dedicated process on how to harvest the SWCNTs from the polymer matrices used to form the biphasic system. The technique is beneficial as it isolates SWCNTs with high purity while simultaneously maintaining their surface intact. To validate the utility of the metallic and semiconducting SWCNTs obtained this way, we transformed them into thin free-standing films and characterized their thermoelectric properties.

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Classification of Recreation Opportunity Spectrum Using Night Lights for Evidence of Humans and POI Data for Social Setting

Sustainability ◽

10.3390/su13147782 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7782

Author(s):

Wenjing Zeng ◽

Yongde Zhong ◽

Dali Li ◽

Jinyang Deng

Keyword(s):

Large Scale ◽

Regional Scale ◽

Hunan Province ◽

Social Settings ◽

Recreation Opportunity Spectrum ◽

City District ◽

Night Lights ◽

Recreational Resources ◽

Metropolitan Counties ◽

Land Types

The recreation opportunity spectrum (ROS) has been widely recognized as an effective tool for the inventory and planning of outdoor recreational resources. However, its applications have been primarily focused on forest-dominated settings with few studies being conducted on all land types at a regional scale. The creation of a ROS is based on physical, social, and managerial settings, with the physical setting being measured by three criteria: remoteness, size, and evidence of humans. One challenge to extending the ROS to all land types on a large scale is the difficulty of quantifying the evidence of humans and social settings. Thus, this study, for the first time, developed an innovative approach that used night lights as a proxy for evidence of humans and points of interest (POI) for social settings to generate an automatic ROS for Hunan Province using Geographic Information System (GIS) spatial analysis. The whole province was classified as primitive (2.51%), semi-primitive non-motorized (21.33%), semi-primitive motorized (38.60%), semi-developed natural (30.99%), developed natural (5.61%), and highly developed (0.96%), which was further divided into three subclasses: large-natural (0.63%), small natural (0.27%), and facilities (0.06%). In order to implement the management and utilization of natural recreational resources in Hunan Province at the county (city, district) level, the province’s 122 counties (cities, districts) were categorized into five levels based on the ROS factor dominance calculated at the county and provincial levels. These five levels include key natural recreational counties (cities, districts), general natural recreational counties (cities, districts), rural counties (cities, districts), general metropolitan counties (cities, districts), and key metropolitan counties (cities, districts), with the corresponding numbers being 8, 21, 50, 24, and 19, respectively.

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Time-resolved PIV measurements of a deflected submerged jet interacting with liquid-gas and liquid-liquid interfaces

Experimental and Computational Multiphase Flow ◽

10.1007/s42757-020-0103-1 ◽

2021 ◽

Author(s):

Stefan Puttinger ◽

Mahdi Saeedipour

Keyword(s):

Liquid Layer ◽

Large Scale ◽

Free Surface Flow ◽

Industrial Applications ◽

Liquid Pool ◽

Surface Flow ◽

Two Phase ◽

Time Resolved ◽

Submerged Jet ◽

Major Interest

AbstractThis paper presents an experimental investigation on the interactions of a deflected submerged jet into a liquid pool with its above interface in the absence and presence of an additional lighter liquid. Whereas the former is a free surface flow, the latter mimics a situation of two stratified liquids where the liquid-liquid interface is disturbed by large-scale motions in the liquid pool. Such configurations are encountered in various industrial applications and, in most cases, it is of major interest to avoid the entrainment of droplets from the lighter liquid into the main flow. Therefore, it is important to understand the fluid dynamics in such configurations and to analyze the differences between the cases with and without the additional liquid layer. To study this problem, we applied time-resolved particle image velocimetry experiments with high spatial resolution. A detailed data analysis of a small layer beneath the interface shows that although the presence of an additional liquid layer stabilizes the oscillations of the submerged jet significantly, the amount of kinetic energy, enstrophy, and velocity fluctuations concentrated in the proximity of the interface is higher when the oil layer is present. In addition, we analyze the energy distribution across the eigenmodes of a proper orthogonal distribution and the distribution of strain and vortex dominated regions. As the main objective of this study, these high-resolution time-resolved experimental data provide a validation platform for the development of new models in the context of the volume of fluid-based large eddy simulation of turbulent two-phase flows.

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Relationship between the Track and Structural Evolution of Hurricane Sandy (2012) Using a Regional Ensemble

Monthly Weather Review ◽

10.1175/mwr-d-18-0121.1 ◽

2018 ◽

Vol 146 (12) ◽

pp. 4279-4302 ◽

Cited By ~ 1

Author(s):

Alex M. Kowaleski ◽

Jenni L. Evans

Keyword(s):

Large Scale ◽

Wrf Model ◽

Structural Evolution ◽

Hurricane Sandy ◽

Weather Research And Forecasting ◽

Extratropical Transition ◽

Ensemble Forecasts ◽

High Predictability ◽

Regression Mixture ◽

The Relationship

Abstract An ensemble of 72 Weather Research and Forecasting (WRF) Model simulations is evaluated to examine the relationship between the track of Hurricane Sandy (2012) and its structural evolution. Initial and boundary conditions are obtained from ECMWF and GEFS ensemble forecasts initialized at 0000 UTC 25 October. The 5-day WRF simulations are initialized at 0000 UTC 27 October, 48 h into the global model forecasts. Tracks and cyclone phase space (CPS) paths from the 72 simulations are partitioned into 6 clusters using regression mixture models; results from the 4 most populous track clusters are examined. The four analyzed clusters vary in mean landfall location from southern New Jersey to Maine. Extratropical transition timing is the clearest difference among clusters; more eastward clusters show later Sandy–midlatitude trough interaction, warm seclusion formation, and extratropical transition completion. However, the intercluster variability is much smaller when examined relative to the landfall time of each simulation. In each cluster, a short-lived warm seclusion forms and contracts through landfall while lower-tropospheric potential vorticity concentrates at small radii. Despite the large-scale similarity among the clusters, relevant intercluster differences in landfall-relative extratropical transition are observed. In the easternmost cluster the Sandy–trough interaction is least intense and the warm seclusion decays the most by landfall. In the second most eastward cluster Sandy retains the most intact warm seclusion at landfall because of a slightly later (relative to landfall) and weaker trough interaction compared to the two most westward clusters. Nevertheless, the remarkably similar large-scale evolution of Sandy among the four clusters indicates the high predictability of Sandy’s warm seclusion extratropical transition before landfall.

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