Bid dispersion, competition and wage regulation: some field evidence from public contract bidding in British Columbia

British Sovereign, the commercial strawberry variety of British Columbia, has shown no field evidence of degeneration from the virus disease, yellows, that is attacking the Marshall variety in the Pacific Northwest. However, experimental inoculation of British Sovereign by stolon grafting to a yellows-infected Marshall plant proved the British Sovereign to be susceptible to yellows. As with the Marshall, infected plants were reduced in size and the foliage tended to flatten towards the grounds but, unlike the Marshall, there was no pronounced yellowing. When Fragaria vesca was grafted to a yellows-infected Marshall plant the reaction was rapid and severe. The older leaves flattened to the ground, the young runner tips hooked back, the newly developing leaves, though relatively well proportioned, were minute and yellow at the margins, and the plants eventually died.

Download Full-text

Geotectonics of Cretaceous and Eocene plutons in British Columbia: a paleomagnetic fold test

Canadian Journal of Earth Sciences ◽

10.1139/e77-114 ◽

1977 ◽

Vol 14 (6) ◽

pp. 1246-1262 ◽

Cited By ~ 20

Author(s):

D. T. A. Symons

Keyword(s):

British Columbia ◽

North American ◽

Large Scale ◽

Structural Model ◽

Pole Position ◽

North American Plate ◽

The North ◽

Field Evidence ◽

Coast Plutonic Complex ◽

Skeena River

A total of 295 cores (590 specimens) were collected at 59 sites in the Coast plutonic complex along an E–W section southwest of Kitimat, British Columbia. The sites represent the Ponder, Alastair Lake, and Quottoon plutons in the 40–50 Ma eastern K–Ar age zone and the Ecstall and Butedale plutons in the 64–80 Ma central age zone. After af demagnetization a stable remanent magnetization was isolated at 32 sites and these data were combined with available data from the Skeena River section about 100 km to the north. The remanence directions in sites from the NNW-trending north and south limbs of the Hawkesbury Warp provide a positive fold test when compared to the WNW-trending centre limb directions.In the Eocene eastern age zone the NNW limbs give a concordant pole position relative to the cratonic North American pole whereas the centre limb has undergone ≈ 50° of the counter-clockwise rotation and ≈ 10° of upward tilt of its western end to give a discordant pole. In the late Upper Cretaceous central age zone, the Ecstall–Butedale pluton was tilted 15° to the west on all limbs before the Eocene intrusion and Hawkesbury Warp deformation events to give a NNW-trend pole and WNW-trend pole diverging in opposite directions from the cratonic reference pole.The geologic field evidence from structural trends, from fault, fold, contact, and foliation attitudes, and from distribution of plutonic phases is consistent with the structural model. The regional geotectonic events are related to possible Cenozoic plate interactions on the western margin of the North American plate. This combination of concordant and discordant poles cannot be explained in terms of an excursion of the geomagnetic paleopole during intrusion, a large scale northward translation of the western Cordillera during the Cenozoic, or a combination of clockwise rotations and northward translations on the margin of the advancing North American plate. The fold test and polarity reversal pattern indicate that all plutons acquired a primary thermoremanent magnetization (TRM) during cooling and probably within ≈ 1 Ma after emplacement.

Download Full-text

Eruption of Mount Meager, British Columbia, during the early Fraser glaciation

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2021-0023 ◽

2021 ◽

Author(s):

James K. Russell ◽

Martin L. Stewart ◽

Alexander M. Wilson ◽

Glyn Williams-Jones

Keyword(s):

British Columbia ◽

Volcanic Eruption ◽

Ice Sheet ◽

High Elevation ◽

Pyroclastic Density Current ◽

Density Current ◽

Volcanic Complex ◽

Glacial Cycle ◽

Volcanic Event ◽

Field Evidence

A new 40Ar/39Ar date from a pyroclastic density current deposit preserved on the northern slopes of the Lillooet River valley, British Columbia, indicates an explosive volcanic eruption of the Mount Meager Volcanic Complex (MMVC) at 24.3 ± 2.3 ka. The age of this pyroclastic deposit is a record of the second youngest explosive volcanic event for the MMVC and indicates that Mount Meager has erupted, explosively, at least twice in the past ~25,000 years. The age of the volcanic eruption coincides with the early phase of growth of the Late Wisconsin (Fraser) Cordilleran ice sheet. The deposit constrains the distribution and timing of glacier build-up in southwestern British Columbia over the last glacial cycle and suggests that the ice sheet was absent or thin in the upper Lillooet valley at this time. Field evidence suggests the pyroclastic density current was sourced at high elevation near present-day Plinth Peak and was deposited and preserved on the adjoining Lillooet valley wall. Coeval, proximal valley-filling glacial ice was up to ~120 m thick.

Download Full-text