Geochemical and Petrological Characterization of Ash Samples from Cascade Range Volcanoes

1971 ◽  
Vol 1 (2) ◽  
pp. 261-282 ◽  
Author(s):  
Keith Randle ◽  
Gordon G. Goles ◽  
Laurence R. Kittleman
Keyword(s):  
Pacific Northwest ◽  
Volcanic Ash ◽  
Cascade Range ◽  
Crystalline Material ◽  
Refractive Indices ◽  
Crystalline Materials ◽  
The Pacific ◽  
Volcanic Ashes ◽  
Different Sources

Twenty-nine samples of volcanic ash from the Pacific Northwest were analyzed by instrumental neutron activation techniques, with the aim of distinguishing among ashes from different sources. Preliminary results of petrographic studies of 42 ash or pumice samples are also reported. Geochemical characteristics of Mazama ash are defined, and problems induced by winnowing of crystalline material during transport and by weathering are discussed. Contents of La, Th, and Co, and La/Yb ratios are shown to be good discriminants. Data on refractive indices and on proportions of crystalline materials also aid in distinguishing among the various volcanic ashes studied. Ash and pumice found in archaeological contexts at Fort Rock Cave, Paisley Cave, Wildcat Canyon, and Hobo Cave are all from Mount Mazama, presumably from the culminating cruption of 7000 years ago.

Genetic characterization of Flavobacterium columnare isolates from the Pacific Northwest, USA

2021 ◽  
Author(s):  
Fd Alexandre Sebastião ◽  
K Shahin ◽  
BR LaFrentz ◽  
MJ Griffin ◽  
TP Loch ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Genetic Characterization ◽  
Flavobacterium Columnare ◽  
The Pacific

scholarly journals Characterization of root traits for improvement of spring wheat in the Pacific Northwest

2020 ◽  
Vol 112 (1) ◽  
pp. 228-240 ◽  
Author(s):  
Bikash Ghimire ◽  
Scot H. Hulbert ◽  
Camille M. Steber ◽  
Kim Garland‐Campbell ◽  
Karen A. Sanguinet
Keyword(s):  
Pacific Northwest ◽  
Spring Wheat ◽  
Root Traits ◽  
The Pacific

Postglacial Vegetation and Climate of the Cascade Range, Central Oregon

1995 ◽  
Vol 43 (3) ◽  
pp. 370-381 ◽  
Author(s):  
Debra S. Sea ◽  
Cathy Whitlock
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Climatic Conditions ◽  
Cascade Range ◽  
Pollen Record ◽  
Climate History ◽  
Vegetational Change ◽  
The Pacific ◽  
Closed Forest ◽  
Vegetation And Climate

AbstractPollen data from two sites provide information on the postglacial vegetation and climate history of the Cascade Range. Indian Prairie in the western Cascade Range was colonized by subalpine forests of Pinus, Picea, and Tsuga and open meadows prior to ca. 12,400 14C yr B.P. The treeline lay 500 to 1000 m below its modern elevation and conditions were cooler than at present. From ca. 12,400 to ca. 9950 14C yr B.P. Abies became important and the forest resembled that presently found at middle elevations in the western Cascade Range. The pollen record implies a rise in treeline and warmer conditions than before. From ca. 10,000 to 4000-4500 14C yr B.P., conditions that were warmer and effectively drier than today led to the establishment of a closed forest composed of Pseudotsuga, Abies, and, at lower elevations, Quercus and Corylus. During this period, Gold Lake Bog in the High Cascades was surrounded by closed forest of Pinus and Abies. The early-Holocene pollen assemblages at both Indian Prairie and Gold Lake Bog lack modern analogues, and it is likely that greater-than-present summer radiation fostered unique climatic conditions and vegetation associations at middle and high elevations. In the late Holocene, beginning ca. 4000-4500 14C yr B.P., cooler and more humid conditions prevailed and the modern vegetation was established. A comparison of these sites with others in the Pacific Northwest suggests that major patterns of vegetational change at individual sites were a response to large-scale changes in the climate system that affected the entire region.

Late-Glacial Vegetation and Climate Change in Western Oregon

1998 ◽  
Vol 49 (3) ◽  
pp. 287-298 ◽  
Author(s):  
Laurie D. Grigg ◽  
Cathy Whitlock
Keyword(s):  
Pacific Northwest ◽  
Younger Dryas ◽  
Late Glacial ◽  
Warming Trend ◽  
Cascade Range ◽  
Subalpine Forest ◽  
Coast Range ◽  
The Pacific ◽  
Dry Conditions ◽  
Vegetation And Climate

Pollen records from two sites in western Oregon provide information on late-glacial variations in vegetation and climate and on the extent and character of Younger Dryas cooling in the Pacific Northwest. A subalpine forest was present at Little Lake, central Coast Range, between 15,700 and 14,850 cal yr B.P. A warm period between 14,850 and 14,500 cal yr B.P. is suggested by an increase in Pseudotsuga pollen and charcoal. The recurrence of subalpine forest at 14,500 cal yr B.P. implies a return to cool conditions. Another warming trend is evidenced by the reestablishment of Pseudotsuga forest at 14,250 cal yr B.P. Increased haploxylon Pinus pollen between 12,400 and 11,000 cal yr B.P. indicates cooler winters than before. After 11,000 cal yr B.P. warm dry conditions are implied by the expansion of Pseudotsuga. A subalpine parkland occupied Gordon Lake, western Cascade Range, until 14,500 cal yr B.P., when it was replaced during a warming trend by a montane forest. A rise in Pinuspollen from 12,800 to 11,000 cal yr B.P. suggests increased summer aridity. Pseudotsuga dominated the vegetation after 11,000 cal yr B.P. Other records from the Pacific Northwest show an expansion of Pinus from ca. 13,000 to 11,000 cal yr B.P. This expansion may be a response either to submillennial climate changes of Younger Dryas age or to millennial-scale climatic variations.

scholarly journals Characterization of Environmental Sources of the Human and Animal Pathogen Cryptococcus gattii in British Columbia, Canada, and the Pacific Northwest of the United States

2006 ◽  
Vol 73 (5) ◽  
pp. 1433-1443 ◽  
Author(s):  
Sarah E. Kidd ◽  
Yat Chow ◽  
Sunny Mak ◽  
Paxton J. Bach ◽  
Huiming Chen ◽  
...  
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Sampling Site ◽  
The United States ◽  
Cryptococcus Gattii ◽  
Environmental Distribution ◽  
The Pacific ◽  
Genetic Subtype ◽  
The Central Nervous System

ABSTRACT Cryptococcus gattii has recently emerged as a primary pathogen of humans and wild and domesticated animals in British Columbia, particularly on Vancouver Island. C. gattii infections are typically infections of the pulmonary and/or the central nervous system, and the incidence of infection in British Columbia is currently the highest reported globally. Prior to this emergence, the environmental distribution of and the extent of colonization by C. gattii in British Columbia were unknown. We characterized the environmental sources and potential determinants of colonization in British Columbia. C. gattii was isolated from tree surfaces, soil, air, freshwater, and seawater, and no seasonal prevalence was observed. The C. gattii concentrations in air samples were significantly higher during the warm, dry summer months, although potentially infectious propagules (<3.3 μm in diameter) were present throughout the year. Positive samples were obtained from many different areas of British Columbia, and some locations were colonization “hot spots.” C. gattii was generally isolated from acidic soil, and geographic differences in soil pH may influence the extent of colonization. C. gattii soil colonization also was associated with low moisture and low organic carbon contents. Most of the C. gattii isolates recovered belonged to the VGIIa genetic subtype; however, sympatric colonization by the VGIIb strain was observed at most locations. At one sampling site, VGIIa, VGIIb, VGI, and the Cryptococcus neoformans serotype AD hybrid all were coisolated. Our findings indicate extensive colonization by C. gattii within British Columbia and highlight an expansion of the ecological niche of this pathogen.

scholarly journals Characterization of mercury, arsenic, and selenium in the product streams of the Pacific Northwest Laboratory 6-kg retort

1985 ◽  
Author(s):  
K.B. Olsen ◽  
J.C. Evans ◽  
D.S. Sklarew ◽  
D.C. Girvin ◽  
C.L. Nelson ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Pacific Northwest Laboratory ◽  
The Pacific
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