Some Aspects of the Morphometry of Paraglacial Alluvial Fans in South-central British Columbia

1971 ◽  
Vol 8 (10) ◽  
pp. 1252-1264 ◽  
Author(s):  
J. M. Ryder
Keyword(s):  
British Columbia ◽  
Arid Region ◽  
Arid Regions ◽  
Alluvial Fans ◽  
Statistical Relationship ◽  
Regression Analyses ◽  
South Central ◽  
Relationship Of ◽  
Relief Area ◽  
Mud Flow

The construction of paraglacial alluvial fans commenced during deglaciation and was dependent upon the temporary abundance of glacially formed debris. Correlation and regression analyses for five groups of fans located within the Interior valleys of south-central British Columbia, indicate that fan gradient is significantly related to the relative relief, area, height, and slope of associated basins. These factors exerted an influence upon fan geometry through processes of stream and mud-flow deposition.Paraglacial fans are distinguished from fans of arid regions by their steeper gradients and a weaker statistical relationship of fan gradient with basin parameters which is subject to greater variation between local regions. This is attributed to the plentiful supply of glacial drift and local changes in its character. Since the basins of most paraglacial fans were formed preglacially, whereas arid region fans and associated basins were formed concurrently, a weaker control of basin character upon fan geometry is to be expected for the former.

scholarly journals Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Teresa A. Newsome ◽  
Jean L. Heineman ◽  
Amanda F. Linnell Nemec
Keyword(s):  
British Columbia ◽  
Lodgepole Pine ◽  
Geographic Range ◽  
Regression Analyses ◽  
Relative Height ◽  
Trembling Aspen ◽  
Ecosystem Productivity ◽  
Height Ratio ◽  
Critical Height ◽  
South Central

Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximizedR2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. MaximumR2values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

The Stratigraphy and Morphology of Para-glacial Alluvial Fans in South-central British Columbia

1971 ◽  
Vol 8 (2) ◽  
pp. 279-298 ◽  
Author(s):  
J. M. Ryder
Keyword(s):  
British Columbia ◽  
Volcanic Ash ◽  
Alluvial Fan ◽  
Alluvial Fans ◽  
River Terraces ◽  
South Central ◽  
Multi Level ◽  
Local Base

Alluvial fan construction within the interior valleys of southern British Columbia was dependent upon temporary conditions resulting from deglaciation. Glacial drift was reworked by streams and mudflows to form fans whose composition is dependent upon the nature of the drift supply and the hydrologic character of the parent basin.Stratigraphic evidence suggests that fan building commenced soon after valley floors became ice-free, continued during post-glacial aggradation by major rivers and for some time after wards. Most recently, fans were built upon degradational river terraces. Mazama volcanic ash within fans indicates that their construction continued until after 6600 years B.P. After deposition ceased many fans were dissected either as local base-levels were lowered under the control of degrading major rivers or by fan-head trenching initiated as the debris supply declined. Where fan building persisted during degradation, multi-level fans were constructed.

Middle Eocene sedimentary and volcanic infilling of an evolving supradetachment basin: White Lake Basin, south-central British Columbia

2005 ◽  
Vol 42 (1) ◽  
pp. 49-66 ◽  
Author(s):  
Jason D McClaughry ◽  
David R Gaylord
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Hanging Wall ◽  
Metamorphic Core Complex ◽  
Lake Basin ◽  
Alluvial Fans ◽  
Core Complex ◽  
South Central ◽  
Metamorphic Core ◽  
Okanagan Valley

The middle Eocene White Lake and Skaha formations in the White Lake Basin, British Columbia record the sedimentary and volcanic infilling of a supradetachment basin that developed during the latter stages of Shuswap metamorphic core complex exhumation. The 1.1-km-thick White Lake Formation is characterized by volcanogenic sediment gravity flow, fluvial, and sheetflood facies interbedded with volcanic deposits. Facies relations suggest White Lake strata accumulated on coalesced, west-sloping alluvial fans that drained an active volcanic center. The overlying 0.3-km-thick Skaha Formation records increased tectonism and mass-wasting. Pervasively shattered Skaha avalanche, slide, and sheetflood deposits accumulated on alluvial fans, shed from hanging-wall and footwall sources exposed along the Okanagan Valley fault. Clast compositions of the White Lake and Skaha formations record alluvial and tectonic stripping that locally eliminated hanging-wall blocks. Mylonite clasts in upper Skaha beds imply significant Okanagan Valley fault footwall uplift during the middle Eocene and syntectonic erosion of the Shuswap metamorphic core complex. The syntectonic sedimentary record preserved within the White Lake Basin elucidates the relations and timing between core complex exhumation and extensional tectonism in this region. The White Lake and Skaha formations are the apparent age equivalent of the Klondike Mountain Formation of northern Washington (USA.). White Lake Basin strata, however, are more complexly interstratified, post-depositionally disrupted, and contain a more complete record of core complex unroofing. Variations in the spatial distributions and textural and compositional character of middle Eocene strata in this area underscore the need to exercise care when developing regional-scale sedimentary–tectonic–volcanic models.

DINAMIKA KELOMPOK TANI ANUGERAH MOLLO DI DESA NETPALA KECAMATAN MOLLO UTARA KABUPATEN TIMOR TENGAH SELATAN

2020 ◽  
Vol 21 (1) ◽  
pp. 71-80
Author(s):  
Tanggu Dedo Yeremias ◽  
Ernantje Hendrik ◽  
Ignatius Sinu
Keyword(s):  
Formal Education ◽  
Secondary Data ◽  
Nonparametric Test ◽  
Primary Data ◽  
Economic Factors ◽  
Dynamic Level ◽  
South Central ◽  
Group Members ◽  
Relationship Of ◽  
Socio Economic Factors

ABSTRACT This research has been carried out in the Anugerah Mollo Farmer Group, in Netpala Village, North Mollo District, South Central Timor Regency, starting in March - April 2019. This study aims to determine: (1) The dynamic level of the Anugerah Mollo Farmer Group in Netpala Village, North Mollo District, South Central Timor Regency, (2) Relationship between Socio-economic factors of farmer group members and the level of dynamics of the Anugerah Mollo Farmer Group in Netpala Village, North Mollo District, South Central Timor Regency. Determination of the location of the study carried out intentionally (purposive sampling) The type of data collected is primary data obtained from direct interviews with respondents guided by the questionnaire, while secondary data is obtained from the relevant agencies. To find out the first purpose of the data analyzed using a Likert scale, to find out the second purpose of the data analyzed using the Sperman Rank statistical Nonparametric test. The results of this study indicate that: (1) The level of dynamism of the Anugerah Mollo Farmer Group in Netpala Village, North Mollo District, South Central Timor Regency, is in the very dynamic category of 84%, (2) The relationship of socio-economic factors is only one of the five variables that are significantly related namely land area with a coefficient of rs 0.278 and t = 1.782 count greater than t table 1.699 (p> 0.05), while other social factors such as age, formal education, number of family dependents, and experience of farming show no significant relationship with the level of dynamism of Anugerah Mollo Farmers Group in Netpala Village.

scholarly journals Conservation Evaluation of Lemmon's Holly Fern, Polystichum lemmonii, a Threatened Fern in Canada

2004 ◽  
Vol 118 (2) ◽  
pp. 164
Author(s):  
George W. Douglas
Keyword(s):  
British Columbia ◽  
Road Construction ◽  
Montane Forest ◽  
Mountain Area ◽  
Forest Road ◽  
South Central ◽  
Northern Idaho ◽  
Mining Exploration ◽  
Conservation Evaluation ◽  
Forest Road Construction

In Canada, Lemmon's Holly Fern, Polystichum lemmonii, is restricted to the Baldy Mountain area on the eastern side of the Okanagan River valley in south-central British Columbia. This population represents the northern limits of the species which ranges south through northern Idaho, Washington and Oregon to northern California. In British Columbia, P. lemmonii is associated with ultramafic rocky ridges within a montane forest at an elevation of 1900 m. The population in the Baldy Mountain area is relatively small, unprotected and potentially imperilled by mining exploration, forest road construction or wildfires.

scholarly journals Conservation Evaluation of the Pacific Population of Dwarf Woollyheads, Psilocarphus brevissimus var. brevissimus, in Canada

2006 ◽  
Vol 120 (2) ◽  
pp. 163
Author(s):  
George W. Douglas ◽  
Jenifer L. Penny ◽  
Ksenia Barton
Keyword(s):  
British Columbia ◽  
Coalbed Methane ◽  
Groundwater Levels ◽  
Gas Drilling ◽  
Pacific Population ◽  
South Central ◽  
The Pacific ◽  
Recreational Vehicles ◽  
Forest Openings ◽  
Conservation Evaluation

In Canada, Dwarf Woolly-heads, Psilocarphus brevissimus var. brevissimus, is restricted to the Similkameen River valley, south of Princeton in southwestern British Columbia and the extreme southeast and southwest corners of Alberta and Saskatchewan, respectively. This paper deals with the three British Columbia populations which represent the northwestern limit of the species which ranges from south-central British Columbia, southward in the western United States to Montana, Idaho, Washington, Oregon, Nevada, Utah, Wyoming, California and Baja California, Mexico. In British Columbia, P. brevissimus is associated with calcareous vernal pools and ephemeral pond edges in large forest openings. This habitat is rare in the area the few existing populations could easily be extirpated or degraded through slight changes in groundwater levels, coalbed methane gas drilling, housing development or recreational vehicles.

Trap response of cutworm moths (Abagrotis orbis) to a sex-attractant lure in grape vineyards

2010 ◽  
Vol 142 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Peter J. Landolt ◽  
D. Thomas Lowery ◽  
Lawrence C. Wright ◽  
Constance Smithhisler ◽  
Christelle Gúedot ◽  
...  
Keyword(s):  
British Columbia ◽  
Vitis Vinifera ◽  
Field Experiments ◽  
Sex Attractant ◽  
Early Spring ◽  
South Central ◽  
Tetradecenyl Acetate ◽  
Feltia Jaculifera ◽  
Multiple Field ◽  
Lepidoptera Noctuidae

AbstractLarvae of Abagrotis orbis (Grote) (Lepidoptera: Noctuidae) are climbing cutworms and can damage grapevines, Vitis vinifera L. (Vitaceae), in early spring by consuming expanding buds. A sex attractant would be useful for monitoring this insect in commercial vineyards. (Z)-7-Tetradecenyl acetate and (Z)-11-hexadecenyl acetate were found in extracts of female abdominal tips. In multiple field experiments, male A. orbis were captured in traps baited with a combination of these two chemicals but not in traps baited with either chemical alone. Males were trapped from mid-September to early October in south-central Washington and south-central British Columbia. Other noctuid moths (Mamestra configurata Walker, Xestia c-nigrum (L.), and Feltia jaculifera (Guenée)) were also captured in traps baited with the A. orbis pheromone and may complicate the use of this lure to monitor A. orbis. Abagrotis discoidalis (Grote) was captured in traps baited with (Z)-7-tetradecenyl acetate but not in traps baited with the two chemicals together.

Shackanite and related analcite-bearing lavas in British Columbia

1978 ◽  
Vol 15 (10) ◽  
pp. 1669-1672 ◽  
Author(s):  
B.N. Church
Keyword(s):  
British Columbia ◽  
Great Depth ◽  
Bulk Rock ◽  
Rock Composition ◽  
Bulk Rock Composition ◽  
South Central ◽  
Early Tertiary ◽  
Broad Field ◽  
New Localities

New localities of shackanite and related analcite-bearing lavas have been discovered in a broad field of early Tertiary phonolite and mafic phonolite in south-central British Columbia. The development of primary and secondary analcite in these rocks is probably the result of cooling lava during and shortly after extrusion.The possibility of leucite to analcite transformation in Daly's shackanite is unlikely because of lack of petrographic evidence and a preponderance of Na2O over K2O in bulk rock composition. It is also unlikely that analcite, and particularly groundmass analcite, crystallized at great depth and was transported to surface during eruption.

Paleomagnetism of the Triassic Nikolai Greenstone, McCarthy Quadrangle, Alaska

1977 ◽  
Vol 14 (11) ◽  
pp. 2578-2592 ◽  
Author(s):  
J. W. Hillhouse
Keyword(s):  
British Columbia ◽  
High Temperature ◽  
North America ◽  
Vertical Axis ◽  
Upper Triassic ◽  
Present Position ◽  
Stable Component ◽  
South Central ◽  
Early Mesozoic ◽  
Lamellar Texture

Paleomagnetic evidence indicates that the extensive early Mesozoic basalt field near McCarthy, south-central Alaska, originated far south of its present position relative to North America. Results obtained from the Middle and (or) Upper Triassic Nikolai Greenstone suggest that those basalts originated within 15° of the paleoequator. This position is at least 27° (3000 km) south of the Upper Triassic latitude predicted for McCarthy on the basis of paleomagnetic data from continental North America. The Nikolai pole, as determined from 50 flows sampled at 5 sites, is at 2.2° N, 146.1° E (α95 = 4.8°). The polarity of the pole is ambiguous, because the corresponding magnetic direction has a low inclination and a westerly declination. Therefore, the Nikolai may have originated near 15° N latitude or, alternatively, as far south as 15° S latitude. In addition to being displaced northward, the Nikolai block has been rotated roughly 90° about the vertical axis. A measure of the reliability of this pole is provided by favorable results from the following tests: (1) Within one stratigraphic section, normal and reversed directions from consecutive flows are antipolar. (2) Consistent directions were obtained from sites 30 km apart. (3) Application of the fold test indicated the magnetization was acquired before the rocks were folded. (4) The magnetizations of several pilot specimens are thermally stable up to 550 °C. The stable component is probably carried by magnetite with lamellar texture, a primary feature commonly acquired by a basalt at high temperature during initial cooling of the magma. Geologic and paleomagnetic evidence indicates that the Nikolai is allochthonous to Alaska and that, together with associated formations in southern Alaska and British Columbia, it is part of a now disrupted equatorial terrane.

Sign in / Sign up

Export Citation Format

Share Document