Structural relationships of the Skeena Fold Belt west of the Bowser Basin, northwest British Columbia

1991 ◽  
Vol 28 (6) ◽  
pp. 973-983 ◽  
Author(s):  
Carol A. Evenchick
Keyword(s):  
Middle Jurassic ◽  
Large Scale ◽  
Volcanic Rocks ◽  
Western Boundary ◽  
Thrust Faults ◽  
Fold Belt ◽  
Clastic Rocks ◽  
Structural Style ◽  
Coast Plutonic Complex ◽  
The Difference

The Skeena Fold Belt is a regional fold and thrust belt that extends across most of the width of the northern Intermontane Belt of the Canadian Cordillera. Structural and stratigraphic relationships at its northeast margin show that it developed between latest Jurassic(?) and early Tertiary time, that it involved strata at least as low as Lower and Middle Jurassic Hazelton Group, and that it is characterized by northeast-verging folds and thrust faults. The structures accommodated at least 44% shortening and appear to root to the west.Most of the fold belt is distinguished by folds in thinly layered Jurassic and Cretaceous clastic rocks of the Bowser and Sustut basins. Its boundary is difficult to establish west of the Bowser Basin in poorly layered Middle Jurassic and older strata. However, map relationships show that Hazelton Group strata are folded with Bowser Lake Group. It is suggested here that the fold belt continues westward to the east margin of the Coast Plutonic Complex, where the increase in metamorphic grade and dominance of plutonic rocks effectively mark the western boundary of the Skeena Fold Belt. The difference in structural style between the Bowser Lake Group and massive volcanic rocks of the Hazelton Group is attributed to their difference in competency. Shortening by thrust faults and large-scale folds in volcanic rocks west of the Bowser Basin may balance with shortening by folds and related detachments in Bowser Lake Group farther east.

The southern Coast Mountains, British Columbia: New interpretations from geological, seismic reflection, and gravity data

2013 ◽  
Vol 50 (10) ◽  
pp. 1033-1050 ◽  
Author(s):  
Amanda M.M. Bustin ◽  
Ron M. Clowes ◽  
James W.H. Monger ◽  
J. Murray Journeay
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Middle Jurassic ◽  
Gravity Data ◽  
Normal Faults ◽  
Southern Coast ◽  
Seismic Profiles ◽  
Coast Mountains ◽  
Clastic Rocks ◽  
Coast Plutonic Complex

The southern Coast Mountains of British Columbia are characterized by voluminous plutonic and gneissic rocks of mainly Middle Jurassic to Eocene age (the Coast Plutonic Complex), as well as metamorphic rocks, folds, and thrust and reverse faults that mostly diverge eastward and westward from an axis within the present mountains, and by more localized Eocene and younger normal faults. In the southeastern Coast Mountains, mid-Cretaceous and younger plutons intrude Bridge River, Cadwallader, and Methow terranes and overlap Middle Jurassic through Early Cretaceous marine clastic rocks of the Tyaughton–Methow basin. The combination of geological data with new or reanalyzed geophysical data originating from Lithoprobe and related studies enables revised structural interpretations to be made to 20 km depth. Five seismic profiles show very cut-up and chaotic reflectivity that probably represents slices and segments of different deformed and rearranged rock assemblages. Surface geology, seismic interpretations, physical properties, and gravity data are combined in two profiles across the Coast Mountains to generate two new 2-D density models that are interpreted in terms of the geological units. The western part of the southern Coast Mountains consists primarily of Jurassic to mid-Cretaceous plutons to depths of 20 km with slices of Wrangellia (in the west) and Early Cretaceous volcanic and sedimentary rocks (Gambier group) in the upper 10 km. The eastern part, east of the Owl Creek fault, consists of slices of Cadwallader and Bridge River terranes and Tyaughton–Methow basin strata with limited slices of plutonic rocks at depths less than 10 km. Below that, Eocene and Late Cretaceous plutons dominate for another 10 km.

Stratigraphy and tectonic setting of the upper part of the Cadwallader terrane, southwestern British Columbia

1990 ◽  
Vol 27 (5) ◽  
pp. 702-711 ◽  
Author(s):  
Paul J. Umhoefer
Keyword(s):  
British Columbia ◽  
Middle Jurassic ◽  
Tectonic Setting ◽  
Source Region ◽  
Upper Triassic ◽  
Magmatic Arc ◽  
Clastic Rocks ◽  
Coast Plutonic Complex ◽  
A Minor ◽  
Depositional Setting

The Upper Triassic to Middle Jurassic Cadwallader terrane lies on the northeastern edge of the Coast Plutonic Complex in southwestern British Columbia. Previous work on the Cadwallader Group, the basal unit of the terrane, suggested it was an Upper Triassic (Carnian to middle Norian) volcanic arc and related clastic rocks. Volcanism ceased in early Norian time. A detailed study of the upper part of the Cadwallader terrane (Tyaughton Group and overlying Last Creek formation) shows that it is a sedimentary sequence deposited on the fringe of the inactive Cadwallader magmatic arc. The Upper Triassic (middle to upper Norian) Tyaughton Group consists of nonmarine to shallow-marine clastic rocks and limestones that show sudden changes in depositional setting. The Lower to Middle Jurassic Last Creek formation, a transgressive sequence of clastic rocks, disconformably overlies the Tyaughton Group. The clastic rocks in the two units were derived from a mixed volcanic and plutonic source region that also included a minor metamorphic component and local lower Norian limestones. The stratigraphy of the upper part of the Cadwallader terrane records long-term thermal subsidence of the basin caused by cooling of the magmatic arc after volcanism ceased in the early Norian. The detailed stratigraphy of the upper Cadwallader terrane supports correlation of the Cadwallader with the Stikine terrane, along which it is currently structurally juxtaposed.

scholarly journals Understanding Structural Style of Onshore Timor Basin from Detailed Fieldwork

2019 ◽  
Vol 13 (4) ◽  
pp. 123
Author(s):  
Agus Handoyo Harsolumakso ◽  
Benyamin Sapiie ◽  
Alfend Rudyawan ◽  
Herwin Tiranda ◽  
Ezidin Reski ◽  
...  
Keyword(s):  
Continental Margin ◽  
Hydrocarbon Exploration ◽  
Thrust Faults ◽  
Sedimentary Sequence ◽  
Fold Belt ◽  
Eastern Indonesia ◽  
Structural Style ◽  
Thrust Sheets ◽  
West Timor ◽  
Economic Reserve

Hydrocarbon exploration in Eastern Indonesia region is mainly concentrated in the related convergent area such as Timor Basin. This area is characterized by the development of complex imbricate thrust-fold-belt deformation involving sedimentary sequence from the Australia continental margin. However, the exploration has not been successfully found the potential economic reserve. Our study utilized extensive and detailed fieldwork campaign  presents the structural style on the onshore region of the Timor Basin. Thick-skinned and thin-skinned thrust faults are both presents in West Timor area divided by the syn-orogenic basin. The change in decolement surface is likely to be caused by inversion structures under the thrust sheets. Our present interpretations indicate that these inversion anticlines structure are likely to occur both onshore and offshore.

Pattern of apparent total strain in the bedded anhydrite cap of a folded salt wall

1989 ◽  
Vol 26 (5) ◽  
pp. 983-992 ◽  
Author(s):  
W. M. Schwerdtner ◽  
J. G. Torrance ◽  
J. T. van Berkel
Keyword(s):  
Structural State ◽  
Large Scale ◽  
Canadian Arctic ◽  
Total Strain ◽  
Western Boundary ◽  
Fold Belt ◽  
Clastic Rock ◽  
Nodule Shape ◽  
Straight Segments ◽  
Horizontal Pattern

The dense anhydrite cap of the southern Muskox Ridge salt wall participated in the large-scale buckling of Mesozoic clastic strata at the western boundary of the Tertiary Eureka Sound fold belt on Axel Heiberg Island, Canadian Arctic. This Carboniferous anhydrite is an aggregate of strained diagenetic nodules and contains relict limestone beds that mark the paleohorizontal plane. The well-exposed cap provides an excellent example of fold decollement and redeformation of foliated rocks.The horizontal pattern of the nodule-shape fabric was delineated within folded and straight segments of the cap. Maps for a well-exposed folded segment show systematic variations in the intensity of apparent total strain (r) and the prolateness factor (k). If the nodule fabric pattern of adjacent straight walls represents the prefold structural state of all walls in the area, then the pattern of folding strain can be reconstructed in the southern Muskox Ridge cap. Here, the preflattened anhydrite was deformed by flexural shear in most localities, but was shortened passively near its contact with competent clastic rock.

scholarly journals Seismic and gravity constraints on the crustal architecture of the Intermontane terranes, central Yukon

2017 ◽  
Vol 54 (7) ◽  
pp. 798-811 ◽  
Author(s):  
Andrew J. Calvert ◽  
Nathan Hayward ◽  
Rajesh Vayavur ◽  
Maurice Colpron
Keyword(s):  
Large Scale ◽  
Upper Cretaceous ◽  
Volcanic Rocks ◽  
Three Dimensional ◽  
Flower Structure ◽  
Alluvial Deposits ◽  
Near Surface ◽  
Clastic Rocks ◽  
Reflection Data ◽  
First Arrival

In 2004, two seismic reflection lines were shot across the Mesozoic Whitehorse trough and adjacent terranes. Three-dimensional first-arrival tomographic inversion is used to constrain lithology to 800–1200 m depth, and surface structures are extrapolated into the middle crust using the coincident reflection data. In the Yukon–Tanana terrane, the metasedimentary Snowcap assemblage is characterized by velocities of 4.5–5.5 km/s, while in Quesnellia, velocities of 5.0–6.0 km/s occur at 500 m depth, and probably represent igneous rocks of the Tatchun batholith. Across the Whitehorse trough, velocities >4.0 km/s correspond to clastic rocks of the Jurassic Laberge and Triassic Lewes River groups; velocities <4.0 km/s probably present the clastic Jurassic to Cretaceous Tantalus Formation. Several near-surface units with velocities of 2.0–3.0 km/s are identified; some correlate well with volcanic rocks of the Upper Cretaceous Carmacks Group, but others could be attributable to alluvial deposits or faulting. The Big Salmon fault is interpreted to dip southwest, implying that rocks of the Yukon–Tanana terrane extend beneath Quesnellia. Stikinia and Quesnellia underlie up to 5–8 km of Triassic to Early Cretaceous sedimentary strata, and appear to be a single allochthon within an 18–20 km deep synform above the Yukon–Tanana terrane, which we name the Northern Intermontane synform. In general, reflection geometries in the upper crust are complex, but are consistent with large-scale imbricate structures that have been dissected into numerous blocks by displacement along moderately to steeply dipping strike-slip faults, which may be part of a crustal-scale flower structure extending to the base of the crust.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

TO THE PROBLEMS OF COMBATING CORRUPTION IN MODERN RUSSIA AND INTERNATIONAL COOPERATION IN THE FIELD OF ANTI-CORRUPTION

2020 ◽  
Author(s):  
Angela Dranishnikova
Keyword(s):  
Large Scale ◽  
The State ◽  
Point Of View ◽  
Modern Life ◽  
Existing Problems ◽  
Moral Point ◽  
Material Goods ◽  
The Russian Federation ◽  
The Difference ◽  
The Government

In the article, the author reflects the existing problems of the fight against corruption in the Russian Federation. He focuses on the opacity of the work of state bodies, leading to an increase in bribery and corruption. The topic we have chosen is socially exciting in our days, since its significance is growing on a large scale at all levels of the investigated aspect of our modern life. Democratic institutions are being jeopardized, the difference in the position of social strata of society in society’s access to material goods is growing, and the state of society is suffering from the moral point of view, citizens are losing confidence in the government, and in the top officials of the state.

scholarly journals Large-Scale Analysis of the Spatiotemporal Changes of Net Ecosystem Production in Hindu Kush Himalayan Region

2021 ◽  
Vol 13 (6) ◽  
pp. 1180
Author(s):  
Da Guo ◽  
Xiaoning Song ◽  
Ronghai Hu ◽  
Xinming Zhu ◽  
Yazhen Jiang ◽  
...  
Keyword(s):  
Large Scale ◽  
Net Primary Production ◽  
Carbon Sink ◽  
Carbon Sources ◽  
Spatial Dynamics ◽  
Tibet Plateau ◽  
Geostatistical Model ◽  
Hindu Kush ◽  
Temporal And Spatial ◽  
The Difference

The Hindu Kush Himalayan (HKH) region is one of the most ecologically vulnerable regions in the world. Several studies have been conducted on the dynamic changes of grassland in the HKH region, but few have considered grassland net ecosystem productivity (NEP). In this study, we quantitatively analyzed the temporal and spatial changes of NEP magnitude and the influence of climate factors on the HKH region from 2001 to 2018. The NEP magnitude was obtained by calculating the difference between the net primary production (NPP) estimated by the Carnegie–Ames Stanford Approach (CASA) model and the heterotrophic respiration (Rh) estimated by the geostatistical model. The results showed that the grassland ecosystem in the HKH region exhibited weak net carbon uptake with NEP values of 42.03 gC∙m−2∙yr−1, and the total net carbon sequestration was 0.077 Pg C. The distribution of NEP gradually increased from west to east, and in the Qinghai–Tibet Plateau, it gradually increased from northwest to southeast. The grassland carbon sources and sinks differed at different altitudes. The grassland was a carbon sink at 3000–5000 m, while grasslands below 3000 m and above 5000 m were carbon sources. Grassland NEP exhibited the strongest correlation with precipitation, and it had a lagging effect on precipitation. The correlation between NEP and the precipitation of the previous year was stronger than that of the current year. NEP was negatively correlated with temperature but not with solar radiation. The study of the temporal and spatial dynamics of NEP in the HKH region can provide a theoretical basis to help herders balance grazing and forage.

scholarly journals Can Mandatory Disclosure Policies Promote Corporate Environmental Responsibility?—Quasi-Natural Experimental Research on China

2021 ◽  
Vol 18 (11) ◽  
pp. 6033
Author(s):  
Yue Liu ◽  
Pierre Failler ◽  
Liming Chen
Keyword(s):  
Property Rights ◽  
Large Scale ◽  
Environmental Responsibility ◽  
Mandatory Disclosure ◽  
Corporate Environmental Responsibility ◽  
Disclosure Policy ◽  
Protection Information ◽  
The Difference ◽  
Csr Disclosure ◽  
Corporate Social

Corporate environmental responsibility (CER) is an important component of the corporate social responsibility (CSR) report, and an important carrier for enterprises to disclose environmental protection information. Based on the corporate micro data, this paper evaluates the effect of a mandatory CSR disclosure policy on the fulfillment of corporate environmental responsibility by adopting the difference-in-differences model (DID) with the release of a mandatory disclosure policy of China in 2008 as a quasi-natural experiment. The study draws the following conclusions: First, a mandatory CSR disclosure policy can promote the fulfillment of CER. Second, after the implementation of a mandatory CSR disclosure policy, enterprises can improve their CER level through two channels: improving the quality of environmental management disclosure and increasing the number of patents. Third, the heterogeneity of the impacts of mandatory CSR disclosure on CER is reflected in three aspects: different CER levels, different corporate scales and a different property rights structure. In terms of the CER level, there is an inverted U-shaped relationship between the CER level and mandatory CSR disclosure effect. In terms of the corporate scale, mandatory disclosure of CSR plays a greater role in large-scale enterprises. In terms of the structure of property rights, mandatory CSR disclosure has a greater effect on non-state-owned enterprises.

scholarly journals Investigating the properties of a galaxy group at z = 0.6

2020 ◽  
Vol 15 (S359) ◽  
pp. 188-189
Author(s):  
Daniela Hiromi Okido ◽  
Cristina Furlanetto ◽  
Marina Trevisan ◽  
Mônica Tergolina
Keyword(s):  
Large Scale ◽  
The Other ◽  
Numerical Density ◽  
Spectroscopy Data ◽  
Stellar Kinematics ◽  
Galaxy Groups ◽  
The Galaxy ◽  
The Difference ◽  
The Impact ◽  
The Universe

AbstractGalaxy groups offer an important perspective on how the large-scale structure of the Universe has formed and evolved, being great laboratories to study the impact of the environment on the evolution of galaxies. We aim to investigate the properties of a galaxy group that is gravitationally lensing HELMS18, a submillimeter galaxy at z = 2.39. We obtained multi-object spectroscopy data using Gemini-GMOS to investigate the stellar kinematics of the central galaxies, determine its members and obtain the mass, radius and the numerical density profile of this group. Our final goal is to build a complete description of this galaxy group. In this work we present an analysis of its two central galaxies: one is an active galaxy with z = 0.59852 ± 0.00007, while the other is a passive galaxy with z = 0.6027 ± 0.0002. Furthermore, the difference between the redshifts obtained using emission and absorption lines indicates an outflow of gas with velocity v = 278.0 ± 34.3 km/s relative to the galaxy.

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