Superimposed Deformations in the Missi Meta-sedimentary Rocks near Flin Flon, Manitoba

1971 ◽  
Vol 8 (2) ◽  
pp. 217-242 ◽  
Author(s):  
Mel R. Stauffer ◽  
Amar Mukherjee
Keyword(s):  
Sedimentary Rocks ◽  
Greenschist Facies ◽  
Axial Plane ◽  
Small Scale ◽  
Second Phase ◽  
Retrograde Metamorphism ◽  
High Angle ◽  
South Side ◽  
Flin Flon

Within the Flin Flon Basin, Precambrian meta-sandstones and conglomerates belonging to the Missi Group have been complexly deformed as a result of three periods of deformation. The first two periods (P1 and P2) involved folding but no apparent faulting, the last (P3) involved both folding and faulting. Progressive metamorphism (M2), within the greenschist facies, occurred during the second phase (P2) and aided in the formation of a pronounced axial-plane foliation (S2). Small-scale folding and retrograde metamorphism (M3) occurred along faults formed during the last phase (P3).The faults in this area all appear to be high angle, oblique-slip reverse faults and can be interpreted as having formed during a single orogenic event (P3) although there is sequence in their initiation. The net-slip directions of different faults are approximately the same, and plunge moderately to the southeast, with either the east or south side upthrown, depending on the attitude of the fault.

Microfabrics of a recumbent fold in cross-bedded sandstones

1979 ◽  
Vol 116 (2) ◽  
pp. 105-116 ◽  
Author(s):  
K. Yagishita ◽  
R. C. Morris
Keyword(s):  
Thin Section ◽  
Similar Type ◽  
Axial Plane ◽  
The Other ◽  
Small Scale ◽  
Fold Axis ◽  
High Angle ◽  
Plane Normal ◽  
Quartz Grains ◽  
Shear Planes

SummaryA thin-section study of the orientation of long-axes of quartz grains was conducted for a similar type fold of overturned cross-bedding in Carboniferous sandstones. Preferred orientation of detrital grains of the fold shows that (a) apparent long-axes of grains are parallel to the axial plane in a plane normal to the fold axis, (b) long-axes of grains in the axial plane are oriented in a high angle to the fold axis, and (c) grains are aligned parallel to the fold axis in a plane perpendicular to the other two directions. From the dimensional orientation of quartz grains in this sample, it is concluded that the overturned fold was made by a shear mechanism immediately following sedimentation in which the original quartz grains were reorientated by small-scale slippage along the shear planes.

scholarly journals Multiscale Mountain Waves Influencing a Major Orographic Precipitation Event

2007 ◽  
Vol 64 (3) ◽  
pp. 711-737 ◽  
Author(s):  
Matthew F. Garvert ◽  
Bradley Smull ◽  
Cliff Mass
Keyword(s):  
Mesoscale Model ◽  
Precipitation Forecast ◽  
Precipitation Event ◽  
Small Scale ◽  
Second Phase ◽  
Mountain Waves ◽  
Low Level ◽  
Orographic Rainfall ◽  
Vertically Propagating ◽  
Horizontal Wavelength

Abstract This study combines high-resolution mesoscale model simulations and comprehensive airborne Doppler radar observations to identify kinematic structures influencing the production and mesoscale distribution of precipitation and microphysical processes during a period of heavy prefrontal orographic rainfall over the Cascade Mountains of Oregon on 13–14 December 2001 during the second phase of the Improvement of Microphysical Parameterization through Observational Verification Experiment (IMPROVE-2) field program. Airborne-based radar detection of precipitation from well upstream of the Cascades to the lee allows a depiction of terrain-induced wave motions in unprecedented detail. Two distinct scales of mesoscale wave–like air motions are identified: 1) a vertically propagating mountain wave anchored to the Cascade crest associated with strong midlevel zonal (i.e., cross barrier) flow, and 2) smaller-scale (<20-km horizontal wavelength) undulations over the windward foothills triggered by interaction of the low-level along-barrier flow with multiple ridge–valley corrugations oriented perpendicular to the Cascade crest. These undulations modulate cloud liquid water (CLW) and snow mixing ratios in the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5), with modeled structures comparing favorably to radar-documented zones of enhanced reflectivity and CLW measured by the NOAA P3 aircraft. Errors in the model representation of a low-level shear layer and the vertically propagating mountain waves are analyzed through a variety of sensitivity tests, which indicated that the mountain wave’s amplitude and placement are extremely sensitive to the planetary boundary layer (PBL) parameterization being employed. The effects of 1) using unsmoothed versus smoothed terrain and 2) the removal of upstream coastal terrain on the flow and precipitation over the Cascades are evaluated through a series of sensitivity experiments. Inclusion of unsmoothed terrain resulted in net surface precipitation increases of ∼4%–14% over the windward slopes relative to the smoothed-terrain simulation. Small-scale waves (<20-km horizontal wavelength) over the windward slopes significantly impact the horizontal pattern of precipitation and hence quantitative precipitation forecast (QPF) accuracy.

A Discussion on global tectonics in Proterozoic times - Late Proterozoic cratonization in southwest Saudi Arabia

1976 ◽  
Vol 280 (1298) ◽  
pp. 517-527 ◽  
Keyword(s):  
Saudi Arabia ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Granulite Facies ◽  
Greenschist Facies ◽  
Arabian Shield ◽  
Granulite Facies Metamorphism ◽  
Quartz Monzonite ◽  
Facies Metamorphism ◽  
Global Tectonics

Early cratonal development of the Arabian Shield of southwestern Saudi Arabia began with the deposition of calcic to calc-alkalic, basaltic to dacitic volcanic rocks, and immature sedimentary rocks that subsequently were moderately deformed, metamorphosed, and intruded about 960 Ma ago by dioritic batholiths of mantle derivation (87Sr/86Sr = 0.7029). A thick sequence of calc-alkalic andesitic to rhyodacitic volcanic rocks and volcanoclastic wackes was deposited unconformably on this neocraton. Regional greenschistfacies metamorphism, intensive deformation along north-trending structures, and intrusion of mantle-derived (87Sr/86Sr = 0.7028) dioritic to granodioritic batholiths occurred about 800 Ma. Granodiorite was emplaced as injection gneiss about 785 Ma (87Sr/86Sr = 0.7028- 0.7035) in localized areas of gneiss doming and amphibolite to granulite facies metamorphism. Deposition of clastic and volcanic rocks overlapped in time and followed orogeny at 785 Ma. These deposits, together with the older rocks, were deformed, metamorphosed to greenschist facies, and intruded by calc-alkalic plutons (87Sr/86Sr = 0.7035) between 600 and 650 Ma. Late cratonal development between 570 and 550 Ma involved moderate pulses of volcanism, deformation, metamorphism to greenschist facies, and intrusion of quartz monzonite and granite. Cratonization appears to have evolved in an intraoceanic, island-arc environment of comagmatic volcanism and intrusion.

scholarly journals The Development of an Android-Based Dictionary for Blind

2020 ◽  
Vol 14 (11) ◽  
pp. 76
Author(s):  
Novi Eka Susilowati ◽  
Imam Syafi'i ◽  
Aftina Aftina ◽  
Azzhan Syahrul ◽  
Dwi Prasetyo Nogroho ◽  
...  
Keyword(s):  
Product Development ◽  
Scale Validation ◽  
Visual Impairments ◽  
Development Model ◽  
Small Scale ◽  
Second Phase ◽  
Voice Input ◽  
Average Percentage ◽  
Input And Output

This study aims to develop an Android-based Indonesian dictionary for the blind. This study was developed using the Borg & Gall development model with some adjustments to the needs of this study. The stages of product development are (1) preliminary studies, (2) planning, (3) product development, (4) product validation, (5) first phase revision, (6) trials, (7) second phase revision, and (8) dissemination. The product developed is an android-based dictionary application with voice input and output. This developed product has been validated and tested on a small scale. Validation is carried out for material expert validators, media experts, and practitioners; while small-scale trials were conducted on 5 people with visual impairments. The results of product validation and trial show that the product developed is feasible to be implemented with an average percentage rating of 91.93%. The product developed provides benefits to the blind, which makes it easier to understand the meaning of words in the dictionary and increases the independence of the blind.

Development of Computer Vision Technique for in Situ Soil Characterization

1996 ◽  
Vol 1526 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Roman D. Hryciw ◽  
Scott A. Raschke
Keyword(s):  
Computer Vision ◽  
Vision System ◽  
Cohesionless Soil ◽  
Software Systems ◽  
Small Scale ◽  
Second Phase ◽  
Video Images ◽  
Subsurface Soil ◽  
Different Levels

Construction and rehabilitation of highways, tunnels, and bridges require detailed information about subsurface stratigraphy. This study presents development of a new method for characterizing subsurface soil in situ using computer vision. Hardware and software systems are integrated to obtain the grain-size distribution (GSD) of subsurface soils continuously with depth and to identify small-scale subsurface anomalies. Research is being conducted in three phases. The first phase consists of measuring the GSD of detached cohesionless soil specimens in the laboratory from digital images obtained with a computer vision system (CVS). The second phase uses the CVS to develop image processing and analysis techniques to classify soil assemblies in the laboratory and identify subsurface anomalies by simulating the manner in which images will be acquired in situ. A texture analysis approach has been developed that can detect changes in stratigraphy. The technique has been successful in identifying different types of dry, uniformly graded soils. Finally, a subsurface vision probe is being designed and constructed that will capture video images at three different levels of magnification continuously with depth.

scholarly journals Structural characterization of the internal domain of Paraguai Belt, in the Cangas region, south central portion of Mato Grosso, Brazil

2015 ◽  
Vol 45 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Bruno de Siqueira Costa ◽  
Carlos Humberto da Silva ◽  
Ana Cláudia Dantas da Costa
Keyword(s):  
Gold Mineralization ◽  
Axial Plane ◽  
Second Phase ◽  
Mato Grosso ◽  
Quartz Veins ◽  
South Central ◽  
Third Phase ◽  
Crenulation Cleavage ◽  
Internal Domain

The structural study of rocks in the district of Cangas showed the identification of three phases of deformation for the Cuiabá Group in this region. The main structure oriented 120/27 is related to the first phase of deformation defined by a slate cleavage, parallel to the bedding and to the axial plane of recumbent folds. In the early stages of this phase a family of quartz veins (V1) was generated, arranged parallel to the structures of this phase of deformation, being all almost deformed. The second phase of deformation formed a crenulation cleavage (Sn+1), axial plane of opened to gentle and asymmetric normal folds, with preferential orientation 110/68. The third phase of deformation is represented by a set of centimetric to decametric scale fractures and faults with metric slip that cut all previous structures, with orientations 35/82. Related to this phase of deformation occurs a second family of quartz veins (V2), which fills the fractures related to Dn+2 and may or may not be carrying gold mineralization.

Time-Domain Simulation of Subsea Equipments Installation Using Hydrodynamic Derivatives

2020 ◽  
Author(s):  
Emerson M. de Andrade ◽  
Joel S. Sales ◽  
Antonio C. Fernandes ◽  
Mario L. Ribeiro ◽  
Pedro V. Teixeira
Keyword(s):  
Hydrodynamic Forces ◽  
Dynamic Responses ◽  
Elastic Behavior ◽  
Strong Interactions ◽  
Small Scale ◽  
Complex Geometries ◽  
Second Phase ◽  
Current Profile ◽  
Resonance Effects ◽  
Hydrodynamic Derivatives

Abstract The installation of a subsea equipment such as manifold needs careful planning and coordination. Studies on the behavior of the dynamic responses are crucial to guarantee safety. Some important factors in these operations include the current profile, waves characteristics, winches motions at topside, and the elastic behavior of the cable (due to resonance effects). Currently, most of the available commercial codes use simplified models for the hydrodynamic forces of submerged equipment. However, for cases with complex geometries and strong interactions with the environmental loads, those models fail to represent correctly the dynamics. In this paper we present an initial method and a hydrodynamic model to include terms that allow the modelling of complex behavior of submerged complex geometries by using hydrodynamic derivatives extracted from model tests. To verify the procedure, tests were performed both at a flume tank and at a towing tank. The model was implemented in a commercial code by using a Simplified Buoy model, to which a python procedure that calculated the hydrodynamic forces was attached. The study was divided into two phases: the first one consisted of the verification of the effectiveness of the external routine. This was done for a manifold in 1DOF and then in 6 DOF. In the second phase, the dynamic maneuvering model using Hydrodynamic Derivatives was implemented as an external routine and, using the output from dynamic excitation experiments at small scale with a manifold, kinematical behavior results were compared. Results showed good adherence, although some further investigations are still needed.

scholarly journals Modelling a Snowdrift by Means of Activated Clay Particles

1985 ◽  
Vol 6 ◽  
pp. 48-52 ◽  
Author(s):  
Yutaka Anno
Keyword(s):  
Angle Of Repose ◽  
Scale Model ◽  
Small Scale ◽  
High Angle ◽  
Clay Particles ◽  
Wide Range ◽  
Wet Snow ◽  
Scale Modelling ◽  
Natural Snow ◽  
Small Scale Model

This paper presents a small scale modelling of a snowdrift using activated clay particles.Characteristic properties of activated clay particles, which are different from model snow particles proposed previously by other investigators, are fineness, high angle of repose and wide range of cohesion. Such properties may provide a similitude of a snowdrift and the phenomena caused by wet snow particles in a small scale model.Experimental results presented in this paper show that activated clay particles are the most suitable substitute for natural snow particles in modelling, and indicate also the possibility of using them to model wet snow particles.

Chronological Framework for the Early Talayotic Period in Menorca: The Settlement of Cornia Nou

Radiocarbon ◽  
2014 ◽  
Vol 56 (02) ◽  
pp. 411-424 ◽  
Author(s):  
Montserrat Anglada ◽  
Antoni Ferrer ◽  
Lluís Plantalamor ◽  
Damià Ramis ◽  
Mark van Strydonck ◽  
...  
Keyword(s):  
Second Phase ◽  
Archaeological Excavation ◽  
The South ◽  
The West ◽  
South Side ◽  
Early Stages ◽  
Architectural Structures

The prehistoric site of Cornia Nou (Menorca) features a number of well-preserved architectural structures belonging to the Talayotic culture. Over the last 6 yr, a team linked to the Museum of Menorca has conducted an archaeological excavation project of a large rectangular building attached to the south side of a substantial and massivetalayot, which is considered the westerntalayot.The main objective of this paper is to present the chronological framework of this building, specifying the period of use and the time of abandonment of the building, as well as the dating of the different phases of its construction. A total of 2714C analyses were obtained from samples of the stratigraphic layers and architectonic structures inside the South Building (SB). This research has provided new insights concerning the early stages of the Talayotic culture. The14C dates allow us to place the first recorded occupation phase of the SB in an interval dated within 1100–900 BC (phase 4). A second phase in the occupation of the SB dates to ∼900–800 BC (phase 5). A final occupation phase could be situated between 800–600 BC (phase 6). However, this record provides evidence to suggest that the construction of the westtalayotmay pertain to a time before the beginning of the 1st millennium cal BC.

Coeval sedimentation, magmatism, and fold-thrust belt development in the Trans-Hudson Orogen: geochronological evidence from the Wekusko Lake area, Manitoba, Canada

1999 ◽  
Vol 36 (2) ◽  
pp. 293-312 ◽  
Author(s):  
Kevin M Ansdell ◽  
Karen A Connors ◽  
Richard A Stern ◽  
Stephen B Lucas
Keyword(s):  
Regional Metamorphism ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Lake Area ◽  
Thrust Belt ◽  
Fold And Thrust Belt ◽  
Minimum Age ◽  
Flin Flon ◽  
Felsic Volcanic

Lithological and structural mapping in the east Wekusko Lake area of the Flin Flon Belt, Trans-Hudson Orogen, suggested an intimate relationship between magmatism, fluvial sedimentation, and initiation of fold and thrust belt deformation. Conventional U-Pb geochronology of volcanic rocks in fault-bounded assemblages provides a minimum age of 1876 ± 2 Ma for McCafferty Liftover back-arc basalts, and ages of between 1833 and 1836 Ma for the Herb Lake volcanic rocks. A rhyolite which unconformably overlies Western Missi Group fluvial sedimentary rocks has complex zircon systematics. This rock may be as old as about 1856 Ma or as young as 1830 Ma. The sedimentary rocks overlying this rhyolite are locally intercalated with 1834 Ma felsic volcanic rocks, and yield sensitive high resolution ion microprobe (SHRIMP) U-Pb and Pb-evaporation detrital zircon ages ranging from 1834 to 2004 Ma. The Eastern Missi Group is cut by an 1826 ± 4 Ma felsic dyke, and contains 1832-1911 Ma detrital zircons. The dominant source for detritus in the Missi Group was the Flin Flon accretionary collage and associated successor arc rocks. The fluvial sedimentary rocks and the Herb Lake volcanic rocks were essentially coeval, and were then incorporated into a southwest-directed fold and thrust belt which was initiated at about 1840 Ma and active until at least peak regional metamorphism.

Sign in / Sign up

Export Citation Format

Share Document