A comparative 40Ar/39Ar study of the Kapuskasing structural zone and the Wawa gneiss terrane: thermal and tectonic implications

1990 ◽  
Vol 27 (6) ◽  
pp. 787-793 ◽  
Author(s):  
Margarita Lopez Martinez ◽  
Derek York
Keyword(s):  
Low Temperature ◽  
Northern Region ◽  
Canadian Shield ◽  
Southern Region ◽  
Closure Temperature ◽  
Superior Province ◽  
Tectonic Implications ◽  
Differential Uplift ◽  
Alkaline Complexes

40Ar/39Ar studies were performed on rocks from two traverses within the southern Superior Province of the Canadian Shield: the Racine traverse across the Wawa gneiss terrane and the Shawmere traverse in the highest grade rocks of the Kapuskasing structural zone (KSZ). Evidence of differential uplift between the two regions was obtained from the hornblende samples analysed. The results suggest that the Wawa gneiss terrane cooled below the hornblende closure temperature about 2570 Ma ago, whereas the KSZ region remained at depth, above the hornblende closure temperature, until about 2450 Ma ago. The Racine biotite samples indicate earlier cooling for the northern region in respect to the southern region within the Wawa gneiss terrane. This would imply tilting in a roughly north-south direction about 2300 Ma ago. Low ages (ca. 1100 Ma) obtained in low-temperature fractions of the microcline samples record the intrusion of the alkaline complexes.

The Spatial and Temporal Distribution of Lightning Strikes and Their Relationship with Vegetation Type, Elevation, and Fire Scars in the Northern Territory

2007 ◽  
Vol 20 (7) ◽  
pp. 1161-1173 ◽  
Author(s):  
Musa Kilinc ◽  
Jason Beringer
Keyword(s):  
Large Scale ◽  
Vegetation Type ◽  
Northern Region ◽  
Northern Territory ◽  
Southern Region ◽  
Transitional Period ◽  
Geographical Information ◽  
Coastal Regions ◽  
Fire Scars ◽  
Lightning Strikes

Abstract In this paper the authors explore the spatial and temporal patterns of lightning strikes in northern Australia for the first time. In particular, the possible relationships between lightning strikes and elevation, vegetation type, and fire scars (burned areas) are examined. Lightning data provided by the Bureau of Meteorology were analyzed for a 6-yr period (1998–2003) over the northern, southern, and coastal regions of the Northern Territory (NT) through the use of Geographical Information Systems (GIS) to determine the spatial and temporal characteristics of lightning strikes. It was determined that the highest densities of lightning strikes occurred during the monsoon transitional period (dry to wet) and during the active monsoon periods, when atmospheric moisture is highest. For the period of this study, lightning was far more prevalent over the northern region (1.21 strikes per km2 yr−1) than over the southern (0.58 strikes per km2 yr−1) and coastal regions (0.71 strikes per km2 yr−1). Differences in vegetation cover were suggested to influence the lightning distribution over the northern region of the NT, but no relationship was found in the southern region. Lightning strikes in the southern region showed a positive relationship with elevations above 800 m, but no relationship was found in the northern region, which could be due to the low-lying topography of the area. A comparison of lightning densities between burned and unburned areas showed high variability; however, the authors suggest that, under ideal atmospheric conditions, large-scale fire scars (>500 m) could produce lightning strikes triggered by either enhanced free convection or mesoscale circulations.

scholarly journals Comparative Analysis of Effects of Heavy Vehicles on Roads in Southern and Northern Nigeria

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
C. C. Osadebe ◽  
H. A. Quadri
Keyword(s):  
Northern Region ◽  
Design Guidelines ◽  
Traffic Volume ◽  
Southern Region ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Passenger Cars ◽  
The Road ◽  
Equivalency Factors ◽  
On The Road

The prevalence of flexible pavement deterioration in the country has been adduced largely by highway researchers to trucks or heavy vehicles carrying much in excess of permitted legal limits. This study investigated levels of deterioration of Abuja-Kaduna-Kano road (Northern region) and Port Harcourt-Enugu road (Southern region) caused by heavy vehicles through a 14 day traffic counts conducted at 5 strategic points each in the Northern and Southern regions. Traffic data generated were analyzed with AASHTO Design Guidelines (1993) to evaluate Equivalent Single Axle Loads (ESALs) and Vehicle Damage effects on the road. The Traffic Volume, Average Daily Traffic (ADT), and Heavy Vehicle per day (HV/day) were estimated to be 2,063,977; 147,427; and 12,246 respectively in the Northern region, while in the Southern region they were estimated to be 750,381; 53,670; and 20,951 respectively. Motorcycles, Passenger cars, Mini-buses/Pick-ups, and Heavy vehicles constitute 18.7%, 49.7%, 23.3% and 8.31% of the total traffic volume respectively in the Northern region while in the South they constitute 4.6%, 30.1%, 26.2% and 39.1% respectively. ESALs were estimated according to AASHTO Design Guidelines in the Northern and Southern regions as 547,730 and 836,208 respectively. An average Load Equivalency Factors (LEFs) of 3.43 and 3.02 were estimated for each heavy vehicle plying the Northern and Southern roads respectively and this could explain some failures (alligator cracks, potholes, depressions, linear or longitudinal cracks along the centre line amongst others) inherent on the road.

Some new measurements of heat flow in the Superior Province of the Canadian Shield

1987 ◽  
Vol 24 (7) ◽  
pp. 1486-1489 ◽  
Author(s):  
Malcolm Drury ◽  
Alan Taylor
Keyword(s):  
Standard Deviation ◽  
Heat Flow ◽  
Canadian Shield ◽  
Superior Province ◽  
Flow Measurements ◽  
Radiogenic Heat ◽  
Radiogenic Heat Production ◽  
Climatic Variations ◽  
The Mean ◽  
A Site

Borehole heat-flow measurements are reported from six new sites in the Superior Province of the Canadian Shield. Values adjusted for glaciation effects, but not for Holocene climatic variations, range from 42 to 56 mW/m2. When these new values are combined with 21 previously published borehole values the mean is 42 mW/m2 with a standard deviation of 11 mW/m2. The data for a site on the Lac du Bonnet batholith suggest that the batholith has a thin veneer, less than 3 km, of rock of high radiogenic heat production at the surface.

Best Practices for Tour Guides in the Northern Region of Jordan

2020 ◽  
pp. 96-118
Author(s):  
Sawsan Khreis ◽  
Foued Benghadbane
Keyword(s):  
Best Practices ◽  
Sustainable Tourism ◽  
Tourism Development ◽  
Northern Region ◽  
Southern Region ◽  
Regional Food ◽  
Sustainable Tourism Development ◽  
Tour Guides ◽  
Regional Tourism ◽  
Alternative Tourism

Tourism investments are concentrated in the southern region of Jordan (Petra and Aqaba). This chapter argues that if food tourism delivers its sustainable benefits, it could be a vehicle for regional tourism development by strengthening the regional food on offer so that deprived areas are regenerated. Villages in Ajloun are selected for the investigation as they are well-known for food production. These villagers have inherited the talent for preparing traditional Jordanian food. This study is the first scientific study conducted to compare two villages in Ajloun, namely Orjan village and Ibbin village for logic justifications: 1) Provide the best example illustrating the best practices of tour guides in Jordan who unconsciously apply the principles of alternative tourism that lead to a sustainable tourism development. 2) This chapter aims to identify many problematic issues such as whether tour guides apply the best practices that are the concrete reflection of sustainable tourism principles.

scholarly journals Do Seedlings Derived from Pinewood Nematode-Resistant Pinus thunbergii Parl. Clones Selected in Southwestern Region Perform Well in Northern Regions in Japan? Inferences from Nursery Inoculation Tests

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 955
Author(s):  
Koji Matsunaga ◽  
Taiichi Iki ◽  
Tomonori Hirao ◽  
Mineko Ohira ◽  
Taro Yamanobe ◽  
...  
Keyword(s):  
Variance Component ◽  
Genetic Resistance ◽  
Northern Region ◽  
Pinus Thunbergii ◽  
Southern Region ◽  
Variance Component Analysis ◽  
Environment Interaction ◽  
Pinewood Nematode ◽  
Northern Regions ◽  
High Sound

Background and Objectives: To determine whether the progeny of pinewood nematode-resistant Pinus thunbergii Parl. clones selected in the southwestern region of Japan could be successful in reforestation in the northern region, we investigated the magnitude of the genotype–environment interaction effect on the resistance against Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle in P. thunbergii. Materials and Methods: We inoculated P. thunbergii seedlings of six full-sib families, with various resistance levels, with B. xylophilus in nurseries at three experimental sites in the northern and southern regions of Japan. All parental clones of the tested families originated from southwestern Japan, and selection of parental clones for resistance was performed in the same region. Sound rates after nematode inoculation were calculated, and survival analysis, correlation analysis and variance component analysis were performed. Results and Conclusions: Families with high sound rate in the southern region also showed a high sound rate in the northern region. In almost all cases, Spearman’s correlation coefficients for sound rates were more than 0.698 among sites. The variance component of the interaction between site and family was small compared to that of site and family separately. Thus, we conclude that the resistant clones selected in the southern region would retain their genetic resistance in the northern regions.

Paleomagnetism of the 1.1 Ga Lackner Lake Complex and tectonics of the Kapuskasing Structural Zone

1989 ◽  
Vol 26 (9) ◽  
pp. 1778-1783 ◽  
Author(s):  
D. T. A. Symons
Keyword(s):  
Fault Zone ◽  
Canadian Shield ◽  
Superior Province ◽  
Thermal Demagnetization ◽  
Abitibi Subprovince ◽  
Reversed Polarity ◽  
Middle Proterozoic

The Middle Proterozoic Lackner Lake Complex is a circular alkalic syenite–carbonatite stock with a diameter of about 5.5 km. It intrudes granulite-rank Archean gneisses in the Kapuskasing Structural Zone of the Wawa Subprovince in the Superior Province of the Canadian Shield. It adjoins the Ivanhoe Lake fault zone, which forms the boundary with the Abitibi Subprovince and is the probable locus of maximum motion between the subprovinces. Specimens from 18 sites in the complex were analyzed paleomagnetically by alternating-field and thermal demagnetization and by saturation isothermal remanence tests. Large, recent viscous remanence components required removal before a stable remanence with a mean direction of 305.4°, 64.1 °(α95 = 5.2°) was isolated. Its pole of 53.7°N, 156.5°W (dp = 6.7°, dm = 8.3°) indicates emplacement at 1108 ± 10 Ma during a brief normal interval in a predominantly reversed-polarity time. This study indicates that there has been no postintrusion tilting of the Kapuskasing Structural Zone and that postintrusion uplift by unroofing did not exceed about 8 km.

A detailed 40Ar/39Ar age study of an Abitibi dike from the Canadian Superior Province

1979 ◽  
Vol 16 (5) ◽  
pp. 1060-1070 ◽  
Author(s):  
J. A. Hanes ◽  
Derek York
Keyword(s):  
Canadian Shield ◽  
Superior Province ◽  
Low Grade ◽  
Polar Wander ◽  
Mafic Mineral ◽  
Fine Grained ◽  
Apparent Polar Wander Path ◽  
Step Heating ◽  
Apparent Age ◽  
Hydrothermal Event

40Ar/39Ar step-heating analyses were performed on 11 felsic and mafic mineral separates from a 90 m wide Precambrian diabase dike of the Abitibi swarm in the Superior Province of the Canadian Shield. Deuterically altered minerals from the dike interior define a primary age of 2150 ± 25 Ma. Updated ages, obtained from felsic separates within 30, and mafic within 1.5 m of the dike border, are evidence of a previously undetected 'Hudsonian' (1.7–1.8 Ga) hydrothermal event in the area. It is possible to distinguish the deuteric from the later hydrothermal alteration by both dating and petrographic methods. The data from this study demonstrate the successful application of 40Ar/39Ar dating to early Proterozoic dikes which have suffered low grade metamorphism. The ages support a north to south sense of motion of the Track 5 apparent polar wander path (APWP). A monotonic decrease in apparent age of felsic spectra indicates reactor induced recoil effects which are correlated with the fine-grained saussurite in the feldspar.

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