Lateral Cryptic Variation in the Great Dyke of Rhodesia

1970 ◽  
Vol 107 (4) ◽  
pp. 319-325 ◽  
Author(s):  
Charles James Hughes
Keyword(s):  
Central Area ◽  
Basic Magma ◽  
Ultramafic Rocks ◽  
Great Dyke ◽  
Cryptic Variation ◽  
Marginal Areas ◽  
Lateral Distance ◽  
Southern Extremity

SummaryA lateral cryptic variation is recognized in layered ultramafic rocks of the Hartley Complex, the largest of the four lopoliths that constitute the Great Dyke. Over a lateral distance of some 120 km, the En content of orthopyroxene from thick, continuous bronzitite layers is up to 6% less at the southern extremity of the Complex than in the central area. This is interpreted to be a result of more rapidly falling temperatures in a thinner body of basic magma that gave rise to a condensed sequence in marginal areas of the lopolith compared to the central area.Following a well-marked period of addition of parental basic magma which appears to have had the incidental effect of linking up the four lopoliths, this compositional relationship in composition is reversed, i.e. the orthopyroxene from the base of an upper bronzitite layer of the southern marginal area of the Hartley Complex is more magnesian than that from the equivalent level in the central area. This is interpreted to arise from the proportion of fresh added magma to previously emplaced and partly crystallized magma being relatively greater in the marginal area than in the central area of the lopolith.

scholarly journals Residential Mobility of Locals and Migrants in Northwest Urban China

2019 ◽  
Vol 11 (13) ◽  
pp. 3507 ◽  
Author(s):  
Xiaoting Jia ◽  
Jun Lei
Keyword(s):  
Residential Mobility ◽  
Urban Areas ◽  
Central Area ◽  
Northwest China ◽  
Urban China ◽  
Residential Satisfaction ◽  
Housing System ◽  
Net Migration ◽  
Migration Direction ◽  
Marginal Areas

With the increase in urbanization, intraurban residential mobility, which underlies urban growth and spatial restructuring, is gradually becoming an integral part of migration in China. However, little is known about the differences in residential mobility between locals and migrants, especially in urban areas in Northwest China. In this study, we aimed to fill this void by investigating the residential mobility patterns among Urumqi’s locals and migrants based on data from a survey and face-to-face interviews that were conducted in 2018. The results first show that the migrants with low homeownership rates relocated more frequently, but had less intentions to move within Urumqi, compared with the locals. A larger proportion of migrants than locals was forced to migrate. Evidence also suggests that the migration directions of locals and migrants differ: both locals and migrants tended to relocate from the southern areas, like Tianshan and Saybark Districts, to northern areas, like Xinshi and Midong Districts, which show the northward migration process of the urban population center in Urumqi. In contrast to the locals, whose net migration direction was from marginal areas to the central area, the net migration direction of migrants was from the central area to the marginal areas, contributing to the formation of migrant communities in the suburbs and spatial segregation between locals and migrants. Lastly, the locals’ intentions to move were widely influenced by age, ethnic group, type of employment, family population, housing area, and residential satisfaction; the migrants’ mobility intentions were mainly influenced by housing type and residential satisfaction. To attract more migrants to the urban areas in Northwest China, a more relaxed migrants’ household registration policy should be implemented, and the inequalities of the social security system and housing system between migrants and locals should be reduced to bridge the gap between migrants and locals.

scholarly journals Tracking the Serpentinite Feet of the Mediterranean Salt Giant

Geosciences ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 352 ◽  
Author(s):  
Vittorio Scribano ◽  
Serafina Carbone ◽  
Fabio Manuella
Keyword(s):  
Central Area ◽  
Mediterranean Area ◽  
Oceanic Lithosphere ◽  
Sea Salt ◽  
Ultramafic Rocks ◽  
Seismic Profiles ◽  
Western Atlantic ◽  
Sea Bottom ◽  
Salt Deposits ◽  
The Mediterranean

Interpretation of seismic profiles and results of scientific drillings in the Mediterranean subseafloor provided indication of gigantic salt deposits which rarely crop out on land, such as in Sicily. The salt giants were ascribed to the desiccation, driven by the solar energy, of the entire basin. Nevertheless, the evaporite model hardly explains deep-sea salt deposits. This paper considers a different hypothesis suggesting that seawater reached NaCl saturation during serpentinization of ultramafic rocks. Solid salts and brine pockets were buried within the serpentinite bodies being later (e.g., in the Messinian) released, due to serpentinite breakdown, and discharged at seafloor as hydrothermal heavy brines. Therefore, sea-bottom layers of brine at gypsum and halite saturation were formed. The model is applicable to the Mediterranean area since geophysical data revealed relicts of an aged (hence serpentinized) oceanic lithosphere, of Tethyan affinity, both in its western “Atlantic” extension (Gulf of Cádiz) and in eastern basins, and xenoliths from Hyblean diatremes (Sicily) provided evidence of buried serpentinites in the central area. In addition, the buoyant behavior of muddled serpentinite and salts (and hydrocarbons) gave rise to many composite diapirs throughout the Mediterranean area. Thus, the Mediterranean “salt giant” consists of several independent geobodies of serpentinite and salts.

scholarly journals Characteristics of Bromus cartharticus Vahl (Poaceae) natural populations collected in the central area of Argentina

2009 ◽  
Vol 66 (2) ◽  
pp. 276-279 ◽  
Author(s):  
Beatriz Rosso ◽  
Elba Pagano ◽  
Pedro Rimieri ◽  
Raúl Ríos
Keyword(s):  
Agronomic Traits ◽  
Natural Populations ◽  
Central Area ◽  
Germplasm Bank ◽  
Marginal Areas

Collection of Bromus catharticus Vahl was carried out in the Argentine humid and sub-humid central area. Sixty-eight natural populations are conserved for medium and long term in Pergamino Germplasm Bank and in IRB Germplasm Bank, and ten morphological and agronomic traits were evaluated in the field during two years. There was variability for the traits considered among the accessions. Those populations from the subhumid area showed differences in valuable attributes for breeding. Exploration of marginal areas for this species might be an effective way to add variability to this collection.

The Quihita-Cunene Layered Gabbroic Intrusion of South-west Angola

1958 ◽  
Vol 95 (3) ◽  
pp. 195-206 ◽  
Author(s):  
P. Stone ◽  
G. M. Brown
Keyword(s):  
Layered Intrusion ◽  
Detailed Examination ◽  
Great Dyke ◽  
Cryptic Variation ◽  
South West ◽  
Isolated Points ◽  
Southern Rhodesia ◽  
Gabbroic Intrusion

AbstractThe detailed examination of rocks recently collected from a traverse and from isolated points within this intrusion has led to the conclusion that it is a large, layered intrusion showing rhythmic and cryptic variation, and comparable in many respects with the Great Dyke of Southern Rhodesia.

The crystallography characteristic of (Mn,Fe)S single crystal

1990 ◽  
Vol 48 (4) ◽  
pp. 898-899
Author(s):  
Jiang Xishan
Keyword(s):  
Single Crystal ◽  
Cast Steel ◽  
Point Group ◽  
Central Area ◽  
Hexagonal Crystal ◽  
Growth Step ◽  
Left And Right ◽  
Relationship Of ◽  
Fcc Structure ◽  
New Discovery

This paper reports the growth step pattern and morphology at equilibrium and growth states of (Mn,Fe)S single crystal on the wall of micro-voids in ZG25 cast steel by using scanning electron microscope. Seldom report was presented on the growth morphology and steppattern of (Mn,Fe)S single crystal.Fig.1 shows the front half of the polyhedron of(Mn,Fe)S single crystal,its central area being the square crystal plane,the two pairs of hexagons symmetrically located in the high and low, the left and right with a certain, angle to the square crystal plane.According to the symmetrical relationship of crystal, it was defined that the (Mn,Fe)S single crystal at equilibrium state is tetrakaidecahedron consisted of eight hexagonal crystal planes and six square crystal planes. The macroscopic symmetry elements of the tetrakaidecahedron correpond to Oh—n3m symmetry class of fcc structure,in which the hexagonal crystal planes are the { 111 } crystal planes group,square crystal plaits are the { 100 } crystal planes group. This new discovery of the (Mn,Fe)S single crystal provides a typical example of the point group of Oh—n3m.

Chronic immobilization stress induces anxiety-related behaviors and affects brain essential minerals in male rats

2020 ◽  
pp. 1-8
Author(s):  
Zafer Sahin ◽  
Alpaslan Ozkurkculer ◽  
Omer Faruk Kalkan ◽  
Ahmet Ozkaya ◽  
Aynur Koc ◽  
...  
Keyword(s):  
Immobilization Stress ◽  
Central Area ◽  
Essential Elements ◽  
Male Rats ◽  
Control Group ◽  
Male Wistar Rats ◽  
Swimming Test ◽  
The Brain ◽  
Center Area ◽  
Chronic Immobilization Stress

Abstract. Alterations of essential elements in the brain are associated with the pathophysiology of many neuropsychiatric disorders. It is known that chronic/overwhelming stress may cause some anxiety and/or depression. We aimed to investigate the effects of two different chronic immobilization stress protocols on anxiety-related behaviors and brain minerals. Adult male Wistar rats were divided into 3 groups as follows ( n = 10/group): control, immobilization stress-1 (45 minutes daily for 7-day) and immobilization stress-2 (45 minutes twice a day for 7-day). Stress-related behaviors were evaluated by open field test and forced swimming test. In the immobilization stress-1 and immobilization stress-2 groups, percentage of time spent in the central area (6.38 ± 0.41% and 6.28 ± 1.03% respectively, p < 0.05) and rearing frequency (2.75 ± 0.41 and 3.85 ± 0.46, p < 0.01 and p < 0.05, respectively) were lower, latency to center area (49.11 ± 5.87 s and 44.92 ± 8.04 s, p < 0.01 and p < 0.01, respectively), were higher than the control group (8.65 ± 0.49%, 5.37 ± 0.44 and 15.3 ± 3.32 s, respectively). In the immobilization stress-1 group, zinc (12.65 ± 0.1 ppm, p < 0.001), magnesium (170.4 ± 1.7 ppm, p < 0.005) and phosphate (2.76 ± 0.1 ppm, p < 0.05) levels were lower than the control group (13.87 ± 0.16 ppm, 179.31 ± 1.87 ppm and 3.11 ± 0.06 ppm, respectively). In the immobilization stress-2 group, magnesium (171.56 ± 1.87 ppm, p < 0.05), phosphate (2.44 ± 0.07 ppm, p < 0.001) levels were lower, and manganese (373.68 ± 5.76 ppb, p < 0.001) and copper (2.79 ± 0.15 ppm, p < 0.05) levels were higher than the control group (179.31 ± 1.87 ppm, 3.11 ± 0.06 ppm, 327.25 ± 8.35 ppb and 2.45 ± 0.05 ppm, respectively). Our results indicated that 7-day chronic immobilization stress increased anxiety-related behaviors in both stress groups. Zinc, magnesium, phosphate, copper and manganese levels were affected in the brain.

Shall I Move My Right or My Left Hand?

2003 ◽  
Vol 17 (2) ◽  
pp. 69-86 ◽  
Author(s):  
Claudio Babiloni ◽  
Fabio Babiloni ◽  
Filippo Carducci ◽  
Febo Cincotti ◽  
Claudio Del Percio ◽  
...  
Keyword(s):  
Bimanual Coordination ◽  
Central Area ◽  
Eeg Analysis ◽  
Complementary Information ◽  
Left Hand ◽  
Mirror Movements ◽  
Related Potentials ◽  
Motor Acts ◽  
Abstract Event

Abstract Event-related desynchronization/synchronization (ERD/ERS) at alpha (10Hz), beta (20Hz), and gamma (40Hz) bands and movement-related potentials (MRPs) were investigated in right-handed subjects who were “free” to decide the side of unilateral finger movements (“fixed” side as a control). As a novelty, this “multi-modal” EEG analysis was combined with the evaluation of involuntary mirror movements, taken as an index of “bimanual competition.” A main issue was whether the decision regarding the hand to be moved (“free” movements) could modulate ERD/ERS or MRPs overlying sensorimotor cortical areas typically involved in bimanual tasks. Compared to “fixed” movements, “free” movements induced the following effects: (1) more involuntary mirror movements discarded from EEG analysis; (2) stronger vertex MRPs (right motor acts); (3) a positive correlation between these potentials and the number of involuntary mirror movements; (4) gamma ERS over central areas; and (5) preponderance of postmovement beta ERS over left central area (dominant hemisphere). These results suggest that ERD/ERS and MRPs provide complementary information on the cortical processes belonging to a lateralized motor act. In this context, the results on vertex MRPs would indicate a key role of supplementary/cingulate motor areas not only for bimanual coordination but also for the control of “bimanual competition” and involuntary mirror movements.

The Distribution of Hospitality Services in Uyo Urban, Nigeria

2018 ◽  
pp. 137-150
Author(s):  
Violet Bassey Eneyo
Keyword(s):  
Data Collection ◽  
Global Positioning System ◽  
Central Area ◽  
Positioning System ◽  
Nearest Neighbour ◽  
Global Positioning ◽  
Neighbour Analysis

This paper examines the distribution of hospitality services in Uyo Urban, Nigeria. GIS method was the primary tool used for data collection. A global positioning system (GPS) Garmin 60 model was used in tracking the location of 102 hospitality services in the study area. One hypothesis was stated and tested using the nearest neighbour analysis. The finding shows evidence of clustering of the various hospitality services. The tested hypothesis further indicated that hospitality services clustered in areas that guarantee a sustainable level of patronage to maximize profit. Thus, the hospitality services clustered in selected streets in the metropolis while limited numbers were found outside the city’s central area.

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